AndyUK's Build - 1.2x1.0m Gantry

[AndyUK]

Hi All,

First things first - Thankyou everyone. This forum is an amazing resource. I've spent the past year lurking and researching, and thought it was about time to get a build log started. Now, if you don't mind, lets begin the self-indulgence!

What do I want out of this?
The biggest draw for me is learning the skills in building and improving the thing. I want your opinions and suggestions. Secondly, I want an awesome tool that can help with my DIY projects going forwards - I would like to be able to work primarily in wood (I'm thinking small furniture building, engraving etc), but want to do small things in aluminium too (like parts for models, handy things for the house or whatever). One of the more exciting applications I have in mind for the future is helping my wife with her glass work - either by scoring / cutting / engraving glass, or creating moulds for the kiln.

Tools
So, I intend to expand my garage substantially... but, I have the basics like a chop-saw, bench drill, etc. My designs are conscious of the fact I have (occasional) access to a Bridgeport milling machine and a reasonable size lathe. The largest 'tool' in the garage is me (in every sense)... I'm a Physicist by trade so can handle electronics and equations - I have greater trouble with the structural design aspects and the physical creation, so those are what I want to learn the most about - I've never welded or tapped a hole before, so they're going to be fun to learn.

The Design So Far
I've thusfar chosen a gantry-based design, about 1.2m by 1.0m which gives me a working area of approximately 1.0m by 0.8m. I think this will be large enough for any project I can throw at it, but small enough to fit in the garage and still have a degree of stiffness! I've particularly liked the common design on this forum, and have used Joe Harris' thread (http://www.mycncuk.com/threads/4513-3-Axis-CNC-router) and video logs in particular for ideas and inspiration (cheers!). I've also chosen a L-shape gantry, currently proposed to be created from a rectangular and box section steel extrusion, and a C style carriage to wrap around it, after looking at the gantry design study threads and following through the mathematics (largely helped by the cutting forces calculation spreadsheets on this forum (http://www.mycncuk.com/threads/2017-Unsupported-Precision-Round-Rail-Calculator)). I was thinking of having a dual X-motor setup, which I know is the slightly less-favoured setup around here, but I don't like the idea of large timing belts - they just weird me out. I do plan to use small belts on all the drives though to give myself some gearing and alignment flexibility. I'd expect to go for one of the large Chinese water-cooled spindles with a VFD. I was anticipating welding the square sections for the gantry, and then using the milling machine to give me good parallel even faces - same goes for the large square tubes that the gantry moves along, but they won't be welded. Not sure if the gantry side plates and the z drive plates should be made from 20mm aluminium or steel yet, so would appreciate comments on that aspect - I think the weight is still feasible with steel, and as I can machine it...? I'm also not very good at knowing where it would be good to add adjustment features, and what form they should take.

Heres a few pictures of my plans so far.... Forgive my Solidworks skills... they're not the greatest!
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I'd like your help with...
Everything!
Specifically at the moment, I'm at the stage of wanting to get the build started. I plan to construct the base frame and the adjustable height bed first, which means learning to weld. Before I dive in head first - I'd like your opinions on the overall design and in particular my base and bed design. Is there anything I've completely overlooked? The base is made from 80x80x4mm and the bed is made from 60x60x4mm square mild steel tubing, with the plates and angles you see made from 3mm mild steel. I planned to construct the base in four welded parts which will then bolt together - the two end squares, and the two central sections.

Here are a couple of detail shots:
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Thanks All, and Happy Christmas!

[Clive S]

Andy Welcome to the forum and a merry Xmas.

You have certainly done some good research with the design. I use dual motors and home them independently with no problem.
The usual advise on here is to advise not to order any electronics (or kits of electronic)s as thing often change in the design. I don't think you will need the dual screws to be full length as you can move the nut mounting a bit further back on the gantry side and save about 200 mm of screw length.

I would also consider for the gantry HD ally profile say 90 x 45 two pieces one horizontal and the other on top vertical the slots in them are correct for BK12 bearing mount etc. so make it very simple.

Anyway just two sleeps for Xmas:beer:

[Nr1madman]

Looks awesome!

I see a few improvements in your design that I will use if I start again with a new machine ;)

One thing I cant see clearly is the spacing of the bearings on the gantry sides compared to the spindle?
Its generally recommended to have the cutter inside of the bearings if you look from the side..
And it might be thats the case here.. but cant see clearly ;)

Skickat från min SM-G955F via Tapatalk

[AndyUK]

Andy Welcome to the forum and a merry Xmas.

You have certainly done some good research with the design. I use dual motors and home them independently with no problem.
The usual advise on here is to advise not to order any electronics (or kits of electronic)s as thing often change in the design. I don't think you will need the dual screws to be full length as you can move the nut mounting a bit further back on the gantry side and save about 200 mm of screw length.

I would also consider for the gantry HD ally profile say 90 x 45 two pieces one horizontal and the other on top vertical the slots in them are correct for BK12 bearing mount etc. so make it very simple.

Anyway just two sleeps for Xmas:beer:

Hi Clive,

Thanks for the comments, much appreciated! I'm glad to know dual motor setups will work and I'll have someone to bug when I come across some niggles ;)

I'll try adjusting those motor mounts to see if I can shorten the screw - from memory, I think I put them there to have the motors embedded into the end of the frame (may not work, but its nice to dream - I'm thinking of adding cooling into there...) and I sort of thought having the nut mounted half-way between the linear bearings made sense - I don't suppose you happen to have any advice on placement?

Definitely will head your warning on the electronics - at the very least technology will have advanced somewhat before I'm ready to get them going! ;) I'll also try and run the numbers on the Ally profile.

Best Wishes, and a Happy New Year!





Looks awesome!

I see a few improvements in your design that I will use if I start again with a new machine ;)

One thing I cant see clearly is the spacing of the bearings on the gantry sides compared to the spindle?
Its generally recommended to have the cutter inside of the bearings if you look from the side..
And it might be thats the case here.. but cant see clearly ;)

Skickat från min SM-G955F via Tapatalk

Thanks Nr1madman! I don't think theres anything too original in here, I've just pulled in ideas from a couple of people around here - its essentially intellectual theft! ;)

The spindle vs. gantry spacing is an interesting point; at the moment the spindle is just outside the bearing (see picture below), which I gather isn't ideal. Originally this was so I could get right up to the edge of the waste board - should I make the bearing footprint larger to encompass the spindle or is the current setup okay? If so - do you have any suggestions as to how far within the footprint the spindle needs to go?

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Thanks!
Andy

[Nr1madman]

The way to get ahead is to steal the best ideas and improve on them. So well done ;)

The way you have the bearings probably will work just fine because of the square rails you have chosen to work with. They should take the load.
Just so you know its unnecessary leverage and will intruduce forces that you could avoid.
If you were using other types of rails like unsupported rods it would be a much bigger issue :)

I know I spotted something else that I wanted to comment on but right now Im drawing a blank.. must be the snaps yesterday :D

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[Neale]

You could take the top rails slightly beyond the end of the machine to allow travel of the spindle past the edge of the base board and still keep it within the bearing span. I pinched that idea from somewhere else (sorry - "research") and it works well.

[routercnc]

Design is basically sound. Setting motors inside the section has probably occurred to most people at some point. If worked hard they may reach 80 degrees or more so you may want vent holes in the section.

I can't see how the gantry cross beam connects to the platforms it sits on apart from the small angle bracket. You will need more than that. You can bolt down through lower inner edge of the gantry into the platform on the rectangle and possibly the square if you can get a tool inside. Or if you can weld then cap off the end of the section and drill and tap to fix the side plates. Popular way to do it for steel.

Alum profile was mentioned and this is another way to do it as you can easily tap the ends.

I would go steel as it is stiffer but both can work.

[AndyUK]

The way to get ahead is to steal the best ideas and improve on them. So well done ;)

The way you have the bearings probably will work just fine because of the square rails you have chosen to work with. They should take the load.
Just so you know its unnecessary leverage and will intruduce forces that you could avoid.
If you were using other types of rails like unsupported rods it would be a much bigger issue :)

I know I spotted something else that I wanted to comment on but right now Im drawing a blank.. must be the snaps yesterday :D

Skickat från min SM-G955F via Tapatalk

Thanks Nr1madman, I guess its an easy thing to fix if I'm not happy - just need to remake the end plates to the gantry to extend the bearing location. Let me know as soon as you remember the other issue - personally I'm on 'Bad Santa' ale this evening which is going down a treat...!



You could take the top rails slightly beyond the end of the machine to allow travel of the spindle past the edge of the base board and still keep it within the bearing span. I pinched that idea from somewhere else (sorry - "research") and it works well.

Hi Neale,

Great plan! I guess if I do this or not sort of depends on the gantry rails levelling method I choose. I'd like to avoid epoxy if I can get away with just using the Bridgeport (which has a 4ft bed travel - hence the limitation of these rails to 1.2m) - but I guess that doesn't perfect the height between the two rails, so I may end up with having to epoxy anyway.




Design is basically sound. Setting motors inside the section has probably occurred to most people at some point. If worked hard they may reach 80 degrees or more so you may want vent holes in the section.

I can't see how the gantry cross beam connects to the platforms it sits on apart from the small angle bracket. You will need more than that. You can bolt down through lower inner edge of the gantry into the platform on the rectangle and possibly the square if you can get a tool inside. Or if you can weld then cap off the end of the section and drill and tap to fix the side plates. Popular way to do it for steel.

Alum profile was mentioned and this is another way to do it as you can easily tap the ends.

I would go steel as it is stiffer but both can work.

Thanks - Its really encouraging to have experienced eyes looking over things.

My plan for the motors was, as you point out, cut some ventilation holes in the rails, and to try and mount a fan inside the rail (assuming the vibration isn't too much) - I'm not massively set on having them there, whilst its aesthetically pleasing I can see that placement causing all sorts of headaches while I'm trying to diagnose things!

The gantry cross beam is connected with the small angle bracket, and a pair of M6 bolts from the carriage plate up into the square steel sections (see below - this view is from below the gantry with the bearings removed). I must admit, this connection was one of the most puzzling parts of the design for me, and I'm not entirely sure that this will be up to the job. What I haven't added to the model yet, but intended to do in order to firm up this connection was add a square-ish steel plate to the back of the gantry with bolts into the smaller square steel tube, carriage plate, and gantry side plate (see second picture). I like your idea of welding a cap onto the end, thankyou - although I might not block it off completely and just half-cap to thread into - would be nice to retain an exit path for swarf and I've gathered the impression from youtube that welding things like this completely shut was generally a bad idea?

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Regards the Aluminium profile, I've been running the numbers of 90x45 Heavy Duty profiles against the steel box section. The biggest draw for me simply, as you say, the stiffness of steel - Aluminium's young's modulus is a quarter that of steel. Practically, thats the difference between 0.1mm and 0.05mm max deflection under weight once the profiles are taken into account - I'm not even sure if that'll be noticeable at the accuracy levels this machine will eventually keep - but may as well aim high now while I can!

[routercnc]

Hi Andy,

I think bolting the gantry beams to the platform will be a bit awkward from underneath and will make it difficult to align everything.
Better to bolt from the top side - you will also get a better joint because the bolt will pass through the thin gantry section and tap into the thick platform. These can be cap head bolts, but if tool access it tricky then hex head will be better.

I didn't quite follow your 'square-ish steel plate idea' but if you want to bolt the gantry in place (i.e. without any welding) then better to use a solid block at the top and bolt it to the gantry, and bolt the side plates to that. Will get a nice support from the top of the gantry down to the platforms. The small L corner brackets are not really up to the job.

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I think you said as much but make sure the gantry pieces are connected to each other otherwise you don't get the benefits of the much larger overall shape. Either bolt the inner faces together, using a clearance hole in the rear face of the small square to pass the bolt through, or weld them.

p.s. aluminium is 1/3 the Young's modulus of steel, not 1/4. So in like-for-like sizes steel is stiffer. But as aluminium is less dense (therefore lighter in a like-for-like size) you can increase the aluminium size or wall thickness and recover the stiffness and be no heavier than the steel version. Aluminium profile is easier to bolt together, so good if you don't have a welder. But then aluminium is expensive. In short, use what you feel comfortable working with - either can work well.

[Clive S]

Aluminium profile is easier to bolt together, so good if you don't have a welder. But then aluminium is expensive. In short, use what you feel comfortable working with - either can work well.

It might also be worth noting that the 90x45 ali profile can be tapped 12mm with a spiral tap very easily in the end holes which make a build quite simple.

[Desertboy]

It might also be worth noting that the 90x45 ali profile can be tapped 12mm with a spiral tap very easily in the end holes which make a build quite simple.

Or if you buy it from KJN they'll tap the ends for a couple of quid if you're lacking taps and I remember I think it was alex had issues until he got the right tap then it was super easy.

I never tapped the extrusion I used an impact driver to force the M12 bolts into the extrusion, I used corners and T nuts to keep the extrusion straight (My frame is 9045) but the gantry I recessed the aluminium into the aluminium plates by 5mm each side (20mm thick plates) which kept the gantry straight whilst I bolted it on.
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I got the Hiwin recess wrong so I ended chopping 1.5cm off the Hiwin's which when I checked the Cad model was obviously wrong lol I must have been having a moment.

Hiwin's are rated for 95%+ of their loading capacity when mounted sideways on this is why on my machine I mounted the Hiwin's where the ballscrew is on yours and the ballscrew when you have the hiwins.

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Removes triangles considerably simplifies the build but increase gantry plate height which can be an issue with flex. I'm only cutting wood and I made my gantry mounts 20mm thick so I don't think this is a problem for me. If and when I build again I'm going to build it same way I did before but undersling the ballscrew so it's out of way of any debris.

I have to say the No.1 thing I would do differently is rotating ball nut but if not then 10mm pitch ballscrews my router is very close in size to yours my travel is 130cm*70cm but I got 5mm pitch ballscrews and this is the biggest mistake I made on my build. (If you exclude me blowing up 1 PSU lol)

As for electronics I went with 4 AM882 (£240 new from China, Toroidal transformer for 70v (£80 from Rapid), $5 BOB for control with a PC parallel port and linuxcnc. I do intend to add an 7i73 board (allows me to use ethernet to breakout boards instead of PP) but I would say the setup I have is the bear minimum for a decent router. Stall protection being the bare minimum in a stepper driver.

Good luck with your build.

[AndyUK]

Okay, so its been approximately a year. I suppose I'd better post an update or two!

First things first, current drawings:


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I mulled over the advice I got from Clive and routercnc for a long time. far too long. I repeated my deformation calculations with various materials and geometries. Ultimately, Aluminium won :) There's a few solid reasons:

Cost - It isn't as bad as I expected. The aluminium profiles are only about £50.
Ease of working with. The connection to the side plates is just so much easier.
Deformation is tolerable. I think it increases vs my steel design from 3.0um to 4.9um - Lets be honest, its never getting close to those tolerances elsewhere!
Proven history of this configuration working for others on this forum.


That decision also cemented the plan for making the side plates out of 20mm aluminium plate - and I think they look reasonable. The other factor is that the milling machine is currently in storage a couple of hundred miles away, and at least I can work aluminium in my garage :D This means I'm also planning on going down the epoxy route for levelling the x-axis, and my belief is that the y axis on the ali-profile should be reasonable out of the box (?). That also allowed me to further copy Joe (thanks bud!) and start designing my motor mount locations etc.

Plan for the motors is that they're all going to have a 15mm timing belt connection to the ballscrews. I believe this allows me some flexibility to gear up/down in the future.

I want to start ordering the linear motion bits - so I've got a few questions:

I've up-beefed the x-axis ballscrews to 2010 1100mm. The y axis is currently 1610 750mm, and the z is 1605 250mm. I'm having a little crisis of confidence in these though, so before I bother Fred for a quote, does that sound right to everyone? Does that get appropriate speeds for what I'm planning on doing? I'm probably mostly cutting wood and occasionally glass and aluminium - I guess I can gear the x axis if it becomes a problem? I was planning on 4x 6nm Nema 23s.

Second crisis of confidence about the screws is the bearings. I'm planning for a BK15 and BF15 (one either end, fixed at motor) for the x axis, then BK12 and BF12s for the Y and Z. Add to that a ballnut for each screw, and thats everything right? :)

Finally, I think my linear rails are as follows: All 20mm, 1200 on X, 850 on Y, and 400 on Z. I think I'll need 12 carriages. Sound good?

[AndyUK]

And, just to prove I haven't been completely slacking off since last year - some progress photos!

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Large steel delivery (about three hundred quid for the base frame and adjustable bed + some sizable offcuts). Lots of cutting... then lots of cleaning up the pieces to make them nice and shiny and easy to weld. At this point, also, you know, learnt to weld a bit :)

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Marking up - discovering what marking up fluid is, and then having to find my own tub! At this point I couldn't wait to layout the steel in approximate locations to give me a better idea of size (wife redacted!)

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Worth also mentioning that part of the reason I've been so slow with this project to date is that I started it a couple of months after buying our first home. My workshop needed a little attention due to a steel lintel which rusted and pushed up the top few brick layers, and the window had rotted out - so here's a couple of pictures illustrating what we did with it. We followed this up with a complete rewire. Notice large pile of steel under bench...

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LOTS of drilling, and LOTS of tapping. I said in my first post I'd never tapped a hole before this. Well, Now... lets just say there were evenings I wore blisters! Should probably have got myself a power-tap, but hey, all good experience.

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By this point the milling machine had made it into storage (for various reasons...), and I wanted to get on with my steel plates for the bed. The shape is cosmetic anyhows, so I went ahead and used the solution to hand, which was a jigsaw with a metal blade. Was quite exciting to do a quick visualisation - although a bit of a tight fit before clearing the space for it! Note that one of the key changes I've made is bolting the frame together initially - I still plan to weld it, but I liked the idea that I could assemble then tack weld once I'm happy with the structure and basic alignment. Whilst I doubt it will help much with distortion, it has prevented me from making any big cockups with the basic dimensions of the base frame - and that steel is expensive!

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Time to sort out the angle iron - needed quite a few of these since I started bolting together. Took the opportunity to borrow the bandsaw whilst at the in-laws and get them nicely cut to size. Marking them was a bit of an onerous task, so as my wife had recently taken up 3D printing as a hobby, printed out a jig to prevent me needing to measure! Worked surprisingly well, as our off-the-shelf middle-of-the-range printer is astonishingly accurate on its dimensions.

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Now that I had the angle pieces, I could start bolting the base together. This is pretty much how it stands today - I've added the other two cross bars, and tightened it all down. I was gobsmacked when I went around measuring the dimensions against the CAD model, to find everything was smack on what I designed it to be - although I don't have a meter long pair of calipers so I'm calling close enough!

Next stage is to start assembing the adjustable height bed - this time I'll be welding straight out of the gate, then I need to tack weld the base frame together and design some height adjustable feet. I'm considering drilling into the concrete base of the workshop and attaching it down - thoughts? Otherwise, as I mentioned in my last post, I want to get the linear motion components on order, and order the aluminium profiles for the gantry to begin assembling those.

Thanks for reading this far - its quite fun sharing this now I've eventually gotten around to it! :) I certainly wouldn't be able to get any of this done without the help and guidance I've found on this forum already.

[AndyGuid]

. . . . . . .

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Marking them was a bit of an onerous task, so as my wife had recently taken up 3D printing as a hobby, printed out a jig to prevent me needing to measure! Worked surprisingly well, as our off-the-shelf middle-of-the-range printer is astonishingly accurate on its dimensions. . . . . . . .


Like that thinking! What make and model 3D printer are you using?

The large dimension box section you've used for the base frame is great but I would suggest that, when you get to the welding stage, you stiffen the frame by triangulating with diagonal bracing.

Personally I would brace roughly the bottom half of the side frames (sorry about negating those bottom drilled holes for the adjustable bed. Eek!)

Your build thread reminds me of the build by Joe Harris, and is a good one to follow!

Andy

[AndyUK]

Like that thinking! What make and model 3D printer are you using?

Thanks Andy :) We're using a Creality CR10-S. Was printing accurately with PLA within an hour of opening the box - very pleased with it so far.


Personally I would brace roughly the bottom half of the side frames (sorry about negating those bottom drilled holes for the adjustable bed. Eek!)

So we're on the same page, I guess you're talking about adding the red lines in the diagram below, rather than the green? I suppose if they were removable bracing they wouldn't foul the adjustable bed permanently... I was hoping to use the lower sections of the frame for a second structure, like a coolant trap or something.

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[AndyUK]

I want to start ordering the linear motion bits - so I've got a few questions:

I've up-beefed the x-axis ballscrews to 2010 1100mm. The y axis is currently 1610 750mm, and the z is 1605 250mm. I'm having a little crisis of confidence in these though, so before I bother Fred for a quote, does that sound right to everyone? Does that get appropriate speeds for what I'm planning on doing? I'm probably mostly cutting wood and occasionally glass and aluminium - I guess I can gear the x axis if it becomes a problem? I was planning on 4x 6nm Nema 23s.

Second crisis of confidence about the screws is the bearings. I'm planning for a BK15 and BF15 (one either end, fixed at motor) for the x axis, then BK12 and BF12s for the Y and Z. Add to that a ballnut for each screw, and thats everything right? :)

Finally, I think my linear rails are as follows: All 20mm, 1200 on X, 850 on Y, and 400 on Z. I think I'll need 12 carriages. Sound good?

No readers objected violently, so I've got a quote for the above from Fred. Very helpful and quick service.

First thing he pointed out was that I needed to specify that I'm planning to use timing belts on the ballscrews rather than direct connections, as the machining will be different. Can anyone shed some light on why? Is it a different shaft diameter or is it keyed or flatspotted for a grub screw?

Second point is he has offered two types of BK support, one with upgraded P5 AC bearings. Any thoughts?

[Clive S]

No readers objected violently, so I've got a quote for the above from Fred. Very helpful and quick service.

First thing he pointed out was that I needed to specify that I'm planning to use timing belts on the ballscrews rather than direct connections, as the machining will be different. Can anyone shed some light on why? Is it a different shaft diameter or is it keyed or flatspotted for a grub screw?

Second point is he has offered two types of BK support, one with upgraded P5 AC bearings. Any thoughts?

Probably because on the ball screw where the pulley fits is called the F length I think from memory this is about 25mm if you are using pulleys then tell him to make it 30 or 35mm you can always cut it shorter.

Go for the best bearings re the BK

[Zeeflyboy]

My plan for the motors was, as you point out, cut some ventilation holes in the rails, and to try and mount a fan inside the rail (assuming the vibration isn't too much) - I'm not massively set on having them there, whilst its aesthetically pleasing I can see that placement causing all sorts of headaches while I'm trying to diagnose things!

If motor heat is a concern (and generally they are designed to run hot without a problem, worth a quick check of the specs) you could always plumb them into the water-cooling loop you will have anyway for the spindle. Just a generic water block attached to the motors enough to pull away a good amount of heat - i've seen similar done for 3d printers where the motors are inside of the heated enclosure.

Overall design looks very nice, you've clearly done a good deal of reading and research. I'm sure it'll be a good machine!

End machining will be different re pulley or direct coupling. That is not to say you couldn't make a direct drive coupling end work with a pulley, you'll just be making your life more complicated.... go with best angular contact bearings you can afford.

[AndyUK]

If motor heat is a concern (and generally they are designed to run hot without a problem, worth a quick check of the specs) you could always plumb them into the water-cooling loop you will have anyway for the spindle. Just a generic water block attached to the motors enough to pull away a good amount of heat - i've seen similar done for 3d printers where the motors are inside of the heated enclosure.


What a great idea! It was only this morning I was pondering making some sort of heatsink for them. Last night I read a thread on here from July which was quite negative about enclosed motors. I'd been thinking along the lines of aluminium block and some copper heat pipes, but water cooling is an excellent idea which deserves investigation :)

http://www.mycncuk.com/threads/12075-can-Nema-23-s-be-placed-inside-box-tubing-X-Y-axis


Overall design looks very nice, you've clearly done a good deal of reading and research. I'm sure it'll be a good machine!

Thanks! As I say, mostly ideas are 'borrowed' from others ;) I'd love to make something that looks as professional as your current project (I love the way everything is covered and enclosed on yours) but I think that is a bit beyond me for now... maybe next time eh? :)



End machining will be different re pulley or direct coupling. That is not to say you couldn't make a direct drive coupling end work with a pulley, you'll just be making your life more complicated.... go with best angular contact bearings you can afford.

Cool, thanks for the tip. I'm currently discussing Clive's suggestion with Fred, and taking his advice as he clearly knows his stuff. Hopefully not too far away from getting these major components ordered. Going to go with the upgraded bearings, and I'm also taking the opportunity to get the Spindle + VFD while I'm at it from someone reputable. Hopefully will also cut down on the shipping costs.

[AndyUK]

Very exciting package just arrived!

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Still working my way through it, but all looks spot on so far. Very pleased and impressed by Fred.

For those of you who are trying to price up your builds in the future, I think this set me back approx £1150. It includes everything you see above - all my rails, ballscrews (+bearings and mounts), and spindle, inclusive of delivery, VAT and Customs. I think it would have cost ~£2000 from a UK (re-)seller.

[AndyUK]

Hi All,

Hard at work as ever, just about finished welding the frame and will be painting soon... I've also got the main gantry structure together, and have starting cutting the aluminium components to form the Y and Z carriages. Photos soon, I promise!!

Quick question though - my linear rails on the gantry are collecting a bit of dust - whats the best way to clean and (oil?) them? Any recommendations for grease to flush the HGR20 carriages through with? And I need a grease gun... any advice appreciated.

Thanks in advance folks!

[Lee Roberts]

I'd clean and flush with oil then use some multipurpose lithium 2 grease as its quite cheap to buy, some links on it below :).

Spec me some lube! (http://www.mycncuk.com/threads/11748)

Profiled rails - Installation guidelines and manufacturer comparison chart (http://www.mycncuk.com/threads/4862-Profiled-rails-Installation-guidelines-and-manufacturer-comparison-chart?p=55256#post55256)

Lithium Grease 400g - Toolstation (https://www.toolstation.com/lithium-grease/p89691)

[AndyUK]

Legend! Thankyou - Your forum searching foo is far superior to mine ;)

[AndyUK]

Promised a couple of photos of the aluminium parts... so here we go - Don't judge my sloppyness too harshly ;)

I've been using the printer at work to get drawings printed out as accurately as possible. I'm then using contact adhesive to attach them to the aluminium, which makes the drilling process a lot easier. The drawings get a little busy and unprofessional, but it helps when I'm checking how accurate the printout is to be able to quickly know what each relative dimension should be.

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Oh my life - the counter bore cutters are amazing. I love these things.

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So, after some bandsaw action, some broken drill bits, a screwed up aluminium part (try and spot whats asymmetrical!), and some other parts made, I finally got around to some rough first-time assembly this evening. The rails aren't perfect yet - they're dialed in to about 0.02mm from the surface of the Ali extrusion whilst I'm awaiting my precision straight edge which is back ordered, but the carriage went together like a dream, and runs nice and smoothly along them.

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[Lee Roberts]

Looking good Andy,

I and a few others I know print things out like this and it works quite well, if you set your printer to print at a 1:1 scale, it should print out "reasonably close" to true 1:1, then you can just measure what you get on the print out and adjust your printer settings accordingly, though I've never had to do this as its always been good enough.

Great build keep up the good work !

[AndyUK]

Hi All,

Small progress update; welding and grinding on the frame and bed is completed, I'm currently prettying it up, and will start painting soon. Once my ugly welds are covered up sufficiently I'll share an updated photo ;) I've got the Epoxy sorted, so that'll be the next job on the frame once the weather improves sufficiently.

I'm starting to ponder the electronics, and its all a little overwhelming. I don't think my budget stretches to servos, so steppers it is, and from the quick calculations I've done it appears I'll be wanting the standard ~3nm steppers with a ~70V homebuilt PSU. I'll be putting more thought into specifics and posting my thoughts before ordering them, but I'm utterly lost when it comes to narrowing down drivers.

Lets take Zapp Automations 3.1nm NEMA 23 stepper (https://www.zappautomation.co.uk/home-page-products-2/sy60sth86-3008b-nema-23-stepper-motor-48577.html) for example (it appears to me to be the standard) - it has a bipolar parallel (which appears to be the standard config) max rated current of 4.2A, so I'm thinking any stepper motor driver able to cope with >4.2A will be able to use the motor to it's full potential (more to the point, I'll have to limit the current on the driver). I'll probably want a motor driver capable of microstepping - and in this regime there appears to be named brand and off brand:

Gecko G2xx Drives - the difference appears to be the native stepping resolution and their microstepping capabilities, generally all in the £100+/ea region. I've seen a few US-based bloggers I trust using these and seem quite happy which is tempting.
Leadshine as used by a few people here... £50-100/ea from that I can see.
Random Brands, Same black box... £40-50/ea

Regards microstepping I have 2010 on X, 1610 on Y, and 1605 on Z (currently all planned for 1:1 but pulleys so room to gear) - lets take the 10mm pitch screws, 1.8steps/degree means half stepping nets 0.025mm/step - is that a reasonable target?

So can anyone shed some light on Drivers and point me in the right direction? Maybe point me to a resource which explains whats what, and what I need to look for to identify a reasonable product?


Second, I had originally thought of using a CSMIO/IP-M controller - I liked the ethernet functionality, 24V lines, and the fact that it was well documented, recommended, and provided a command buffer - BUT - I've been very aware that it has two very key draw backs for me: no good slave axis functionality for my dual x-axis screws, and four axis limit which would be a pain in the future if I wanted to add a 4th axis. I'm not keen on the cheaper parallel port breakout board style (rightly or wrongly, I'm kinda dumping the UCxxx controllers in here - please correct me if I'm wrong), but I have been thinking about the ESS ethernet smoothstepper. From what I can tell, it has the capability to handle up to 6 motors which allows future expansion, and can handle the dual screws and independent homing well - but it needs to be combined with a suitable BoB and only provides me with 5v IO which I'll need to put more effort into sorting.

Can someone tell me if I'm on the right lines, or if theres something drastic I'm missing or some better option? I'm really keen to have a robust and smooth machine.

Thanks for listening to the fevered rant this far - double thanks if you're able to put me straight on a question or two!

[Neale]

Microstepping - yes, half-stepping probably gives you as good a resolution as you need for a router, but the thing will run like marbles in a cement mixer! Go to x8 microstepping and it runs much more smoothly. Go much higher and you start to lose torque - x8 or so is a good compromise. That's my experience - steppers just don't run at all smoothly unless you microstep them.

Try some critical speed calculations (there are online calculators available) to see what max speed you can run your ballscrews at. Those X screws will probably go up to around 800RPM (exact figures depend on which calculator you use - my machine uses 1750mm 2005 and I can run up to about 900-1000RPM). Then look at what kind of rapid speed you would like, and work backwards to get pulley ratio. My 3Nm steppers run at around 1000RPM before starting to lose torque, so 1-1 with my ballscrews gives me about 4500-5000mm/min rapid. That's fine for me but your 2010 with, say, 2-3 pulley ratio, would give you more speed and the pulley ratio will increase available torque on the ballscrew to help. But play with the numbers - there are trade-offs here. I am happy with my machine because I mainly do small fiddly work which needs acceleration rather than high max speed but your needs might be different. There are also 4Nm steppers around (I think that CNC4YOU sell them, for example).

Drivers - I use EM806 and am very happy with them. Gecko are popular in the US but remember that they are a US product and there is an automatic bias towards "locally made". Understandably - and i believe that there are now tariffs which penalise Chinese imports! But in the UK we have a wider choice. Main points are enough current capacity (you have identified this), enough voltage headroom (EM806 is rated at 80V which works well with 68-70V PSU), and digital control - partly for smoother motion, partly for stall detect which I feel is vital if you are using dual-motors. Every so often I get a stall for some reason and the machine stops immediately without tearing itself apart. The 806 is a more recent Leadshine offering but there are clones of the previous model whose number I forget) widely available at lower cost. Any driver in this kind of range will support adequate microstepping, almost certainly. Plenty of people use the cheaper version although I chose the 806 as it looked as if the previous version was becoming obsolete. And so it was, but it seems only from Leadshine and the clone industry then took over!

I also use an IP/M. No, it does not properly support dual-axis homing, although assuming you have a way to home your machine, it does understand the concept of a slave axis and will drive it happily. For a long time, I homed my machine via the usual Mach3 option, then disabled the drivers to allow the slave stepper to be turned by hand, and tweaked it until the LED on the proximity switch tripped. Crude but effective. However, someone recently reported on the forum that you could go into the IP/M config tool in Mach3, disable slaving, then use a modified Mach3 homing routine to home X+A at the same time. This works very well. You then go back and re-enable slaving and carry on as before. My machine was built with adjustable targets for X and A, and by tweaking I can get good reliable squaring this way. It's a slight fiddle, but you normally only need to do it once at the start of a session.

The 4-axis limit is more problematic with the IP/M. If I were doing it again, I would probably go UC300ETH plus UB1 breakout board. As far as I can see, this is very similar to the IP/M with 24V signalling and plenty of I/O. And 6 axes! Can't remember now if it does differential signalling to the stepper driver, though, which is an CSMIO feature and, I feel, worth having if possible. Better noise rejection, in short, as with 24V signalling. 24V is useful if you use proximity switches as these typically run with 10V plus. When i tested mine, I found them a bit flaky at their nominal lowest voltage but they are fine at 24V, and I happily run them in pairs in series on X and Y so upper and lower limits go to the same input pin. Keeping XYZA on separate pins is useful on a larger machine as you can home multiple axes simultaneously that way in Mach3 (I home Z for safety, then X and Y at the same time, or XYA at the same time for initial homing as above). Using the UC300 also means that you could look at the UCCNC software in place of Mach3. I still have reservations about Mach4, and you have to be very careful about the exact version of Mach3 you run with the CSMIO plugin.

Anyway, just my thoughts, and I'm sure that others will disagree!

[AndyUK]

Thanks Neale, that was a super helpful post, and its going to take me a few evenings to reply in full!

Lets talk numbers first, because I've being doing these calcs behind the scenes. I've written my own version of irving2008's motor calc sheet. Its basicly the same, but I'm doing the calcs myself so I understand it, and I'm doing all three axis at once. I've also modified it to cope with dual screws on the X (I've doubled the screw inertia then doubled the Est Torque output - which in my head counters the additional drag of driving an extra screw against the additional power output.)

I've set the sheet up here for 5500mm/min, with a 50N (Ali) cutting force. Its currently not setup for gearing at all - and I have a microstepping factor of 1x because I haven't thought how to include these factors yet.

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So, with 2x 4.0 Nm on the X we can just achieve this setup (I say just - as per the original spreadsheet there's a 3x Margin on the required torque), and rapids at 9000mm/min whilst staying below 900rpm (below corner and 80% of critical speeds). Note that although I've simulated 3.1 Nm on the Y and Z, they're massively overkill. Especially the Z.

Questions are - does this look realistic and okay? Is my dual screw fudge acceptable or are there any obvious holes?

Any tips on how to integrate the pulley factor and microstepping? How do I take these results and figure out what gearing to use?

Thanks!

[AndyUK]

Quick Update;

I've decided to go with a 1:1 ratio for now (which was always the intention) but by designing in the pulleys, I'll have the option for change in the future. This means that the dual 4.0Nm on the X should do okay, and despite the overkill, I've gone for 3.1Nm on the Y and Z (thinking being if I have issues with one motor, I'll have an identical one to swap in and out for troubleshooting).

I've also done a lot of investigation around motor drivers, and have ultimately followed Neale's recommendation with the EM806s - they seem to tick all the boxes for me and the stall detection is a really big draw. That, and Zapp's sale means they're very reasonably priced! (£62/ea rather than £105-£110/ea elsewhere).

Still quite undecided about breakout boards / control boards, although I'm moving further away from the CSMIO offerings. Watch this space!

[AndyUK]

Now that I know my motor and drive choices, my thoughts have rushed ahead to the PSU for the drives. This is all speculative, but I wanted to air my thoughts.

We have 2x 4.2A Max steppers, and 2x 4.0A Max steppers. Thats a load of 16.4A at full pelt, but the drivers only need 60-70% of that current. So worst case, I need between 9.9 and 11.4A. Lets call it 12A for the sake of overbuilding things.

The highest inductance of my motors is 3.2mH. So, 32*sqrt(3.2) = 57.2V Ideal voltage. Drivers can take up to 80V.

The secondary voltage of an unregulated PSU is increased by the capacitor bank by a factor of sqrt(2) - So I'm aiming for an ideal secondary voltage of 41V.

12 A * 41 V = 492VA. This is the minimum power of transformer I'll need. Standard size options are therefore a 500VA transformer, or a 625VA transformer would be the next size up. Standard secondary voltages in my range are 2x25V (in Series = 50V), 2x40V (in parallel) or 2x45V (in parallel). I'm therefore looking at a 500 or 625VA transformer with 2x45V secondaries, giving a voltage to the drives of 64V.

Capacitors wise, to achieve a 5V ripple at 50Hz under full load (which keeps me above the ideal supply voltage) I'm looking at C = 12A / (4*50Hz*5V) = 12,000uF. But more won't hurt. Also, while we're talking capacitors, I ideally want them to be able to cope with 2x V (so 120V), but 100V rated caps will probably do the job.

[fgfreek32]

looks like mine,like it25744

[Doddy]

Just a thought with the selection of a transformer - ignoring core flux (not realistic, but bear with me) - you can use the typical twin secondaries not so much in parallel, but as two separate supplies. It costs an additional capacitor (though lower capacitance) and an additional rectifier. It means that your copper losses are reduced on individual supplies and regulation is arguably better. It's an approach that I'm trying with my type of machining (typically machining In X/Y, not 3d profiling) - so I intend to bond Y/Z on one supply and X/A on the second - my thoughts are that only one stepper is likely under load at any point in time on any one supply.

80V drivers?, some common ones in this range are AC/DC - if so just remember that the first thing these will do is rectify/smooth the supply internally.

Your preference to rate the caps at 2x VDC - your money. A bit of head-room is a good idea but 2x is a little bit frivolous. Admittedly mine are more so - at 160VDC (50V secondaries) but that's simply because I had them in the shed as part of a bulk-buy.

[AndyUK]

looks like mine,like it

Thanks! They certainly share a few design ideas don't they? :)


Just a thought with the selection of a transformer - ignoring core flux (not realistic, but bear with me) - you can use the typical twin secondaries not so much in parallel, but as two separate supplies. It costs an additional capacitor (though lower capacitance) and an additional rectifier. It means that your copper losses are reduced on individual supplies and regulation is arguably better. It's an approach that I'm trying with my type of machining (typically machining In X/Y, not 3d profiling) - so I intend to bond Y/Z on one supply and X/A on the second - my thoughts are that only one stepper is likely under load at any point in time on any one supply.

Interesting idea - I don't know much about power supplies and transformers though, so I'll need to do more research! On mine with the two drives on X, I'd be wary of joining the X/A because they'll be drawing significantly more that Y/Z, and they'll be doing so at the same time as each other.


Your preference to rate the caps at 2x VDC - your money. A bit of head-room is a good idea but 2x is a little bit frivolous. Admittedly mine are more so - at 160VDC (50V secondaries) but that's simply because I had them in the shed as part of a bulk-buy.

Good point - but it looks like I'll end up paying about £12-15 for the four capacitors I need, at that price I can afford to over-rate them!

[AndyUK]

So, because I've sorted my motors and drivers before the rest of the control system, I've spent the evening checking that everything works as expected before I pack them away and let the warranties tick away.... At least I'll know they all worked at least once eh?

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Simple setup with a 48VDC power supply I had lying around and an Arduino to generate the pulses. Always nice to see a stepper womble back and forth, and it means as soon as my mechanicals are ready I can test the steppers in place without needing the control system finalised.

[AndyUK]

1x PSU Fabracobbled together.

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Still needs some hot glue on the caps (I've misplaced the glue gun - d'oh) - Testing will need to wait until the Wife gets back from a work trip, I'm not turning this one on whilst I'm alone in the house! Went with a 625VA with 2x 40V secondaries in the end, gave me 45V on the secondary, so hopefully about 63V after rectification and smoothing.

Oh, and yes I'm a muppet and ordered the wrong size capacitor clamps. 3D Printer to the rescue!!

[Nickhofen]

It looks good!

[AndyUK]

Hi All,

Wiring Diagram, V1 attached! Please note future builders, this is a very early days schematic - I don't have half the components and most of these connections are untested.

Questions I'm currently pondering:


Theres currently no ground to the UB1, and by extension anything that it connects to, other than cable shielding. I feel like I should be grounding the motor drivers or something...!
Does the E-Stop circuit look okay?
Need to find Limit and Home switches and then tailor diagram to their requirements.
Need to figure out what I'm doing with the 4th pin on the spindle re grounding. Does the ground go to the VFD like I've shown?
Noise suppression - The VFD and the 24V/60V PSUs will be sharing a mains connection. The garage is on a 16A spur, so it's quite hard to get cable distance between them, is there something I can put into the system to suppress the noise from the VFD?


Thanks Nick, I've been using a few of your diagrams on here and CNC Zone :)

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Edit - Heres the updated version, don't use the one above.

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[Doddy]

Hi All,

Wiring Diagram, V1 attached!

Questions I'm currently pondering:


Theres currently no ground to the UB1, and by extension anything that it connects to, other than cable shielding. I feel like I should be grounding the motor drivers or something...!
Does the E-Stop circuit look okay?
Need to find Limit and Home switches and then tailor diagram to their requirements.
Need to figure out what I'm doing with the 4th pin on the spindle re grounding. Does the ground go to the VFD like I've shown?


Thanks Nick, I've been using a few of your diagrams on here and CNC Zone :)

25828


1) Why? you're driving the stepper drivers through their own opto isolation - no need for common ground there, and I *think* the analogue output from the UB1 for spindle speed control is also an isolated supply. Don't worry about galvanic shielding - the UB1/UC300 isn't shielded so you're gaining nothing.
2) Let someone else answer
3) Let you answer
4) Should ideally go to a common/star earth point, similar to the VFD earth (and the supply lead earth)

Not familiar with the UB1 - can it drive the 24V contractor coil directly?, and back emf?

[AndyUK]

Thanks Doddy,

1) That makes sense. I think I just have a pathological need to make sure everything is grounded as much as possible..!!

4) That's my plan - it looks like that connection is the only place on the VFD to earth it, so I may end up connecting that to both the spindle body via pin 4 and the mains gnd.

Not sure, haven't spec'd a contactor yet, but will look into it. At the moment I don't think I'm asking the UB1 to drive it directly? Its driven by the 24V PSU via the PNOZ.

Re Back EMF, from the VFD? If so I've added a question above about noise suppression above. I guess I'll also get back EMF in the 60V PSU, but was expecting the capacitor bank to help out with that, will that cause issues upstream?

[Doddy]

Back emf: from the coil of the contactor/relay.

But I don’t know the particular UB1 output spec. If a mosfet might find it has a commutatinf diode built in, otherwise place a 1N4001 across the coil, cathode to 24v line, anode to ground

[Nickhofen]

Does this answer one of your your questions about VFD?
http://www.mycncuk.com/threads/4985-VFD-Cable-and-2-2kw-spindle-wiring
About the last question i believe this can do the job :
https://www.aliexpress.com/item/32781939486.html?spm=a2g0s.9042311.0.0.27424c4d4Nk JmR

[AndyUK]

Back emf: from the coil of the contactor/relay.

But I don’t know the particular UB1 output spec. If a mosfet might find it has a commutatinf diode built in, otherwise place a 1N4001 across the coil, cathode to 24v line, anode to ground

Perfect, Thanks


Does this answer one of your your questions about VFD?
http://www.mycncuk.com/threads/4985-VFD-Cable-and-2-2kw-spindle-wiring
About the last question i believe this can do the job :
https://www.aliexpress.com/item/32781939486.html?spm=a2g0s.9042311.0.0.27424c4d4Nk JmR


Cheers Nick!

Little more progress on the Z axis - managed to mill the channels required for the Z ballscrew yesterday. Bridgeport wasn't trammed perfectly, so the surface is a little off, (I was under quite strict time constraints and the tramming worm screw is broken - so its as good as I could get without it) but it will certainly do the job I need it to. Assembled the Z axis for a test-fit late last night, but forgot to take pictures, so they'll follow.

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My monster of an electrical cabinet has also arrived... 800x600x300 is massive, but should fit everything!! Went for the glazed door option, although unfortunately it has some dings in the door - I'm guessing its just a grey hammerite paint touchup job.

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I know I promised frame photos.... but I'm still halfway through painting the bed, and I'm not massively pleased with my 'smooth' hammerite finish. Despite our best efforts, the paint ran all over the place and whilst the surface is smooth, the light clearly reflects the brush strokes. :/ Any advice appreciated!

[Nickhofen]

I use paint rollers to paint my bed,the painting is faster and easier to applied this way .
If you see lines this means that you have to thinner the paint , when the paint is thinner is leveled when applied, but be careful not to use too much thinner.

[AndyUK]

Thanks Nick, what do you use to thin it? How much?

Test assembly of the Z axis with obligatory drill movement test (although I can rotate the screw by hand):
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[Nickhofen]

You have to use the exact thinner type that the company suggest,about how much you will find it on the color container. I usually start with less thinner than the amount the company suggest,then try the thinned paint on a surface with the paint roller and let it seat for about ten minutes .
If it is not transparent and the color is leveled it self,I mean you do not see marks after ten minutes,you can do your job, with the roller you might notice small bubbles in the color,it is ok those are going to disappear when the color cures
If the paint is sticky add thinner, shake well before use!
Make one thick pass and do not repaint after some minutes or hours , because the new paint will dilute the old one and you will end up with a mess....
Good luck!

[AndyUK]

Thanks Nick, the thinners and your advice has really helped. I've recoated it, and although it's still not removed the paint brush lines and the surface is nowhere near perfect, it's improved a lot. I think ultimately, I'll need to take the frame back to bare metal to fix this mess, but then again, it's just looks - the metal is protected as is, so I'm going to forge on regardless.

Also been cleaning up a few of the Z axis components now they're complete, ready for final assembly when I got the surface plate out.

In other news, put my slightly dented but massive cabinet up on the wall... Used a spirit level on the edges... The damn thing is a rombus!! The door is extra wonkey to boot... Serves me right for buying a cheaper cabinet I suppose...

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Next steps...

The current challenge on the base frame front is the epoxy framing and pour - I've sourced the MDF side pieces and cut to size, time to start gluing and siliconing!

On the gantry front, my next challenge is the motor mounts (thats the only thing, besides no belts, stopping me driving the Z and Y with motors).

And on the electronics front, I'm currently sourcing cables and components for the cabinet... its all go!

[AndyUK]

Visited the science museum yesterday, saw this and it made me smile and think of you lot:

25997

But the smile has faded, because today, I've been tackling the demon that is E-P-O-X-Y. Unfortunately, I don't think its gone too well, but I'm going to let it do its thing for two weeks, then if needs be chip it off and start all over.

So, first off, I started by levelling the base frame on its levelling feet. Turns out my longest spirit level has an error in it, and I wasted a good half hour chasing the damn thing until I figured out it changed when rotated 180 degrees. Oops. Trusty digital spirit level to the rescue, which was much easier to flip round every time.

Once my lovely smooth and flat steel beam was level, I then set about mauling it with the grinder. The idea was to give the epoxy something better to stick on to.

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We then assembled the epoxy frame. This seemed to go really well - the only thing i'd change would be the width of those spacers you see over the top of the frame - it was quite a pain in the arse getting below them on the later stages. Take special note of the blue bottle we purchased to do the epoxy pour with - it has a tap on the other side which we thought would be ideal. We then started heating the garage up, got the air temp up to about 28 dungarees, and whilst we were doing this we taped the bottom edge of the epoxy frame, and then used silicone sealant all the way around on both the inside and outside faces (we really don't want any epoxy leaks). We also clamped the frame down onto the bed before doing this.

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After letting all that silicone set, and a bloody-good chineese takeaway, we set about the epoxying. We measured out and mixed the 1.3L in six equal sets by weight, taking a minute to thoroughly stir after each set. Naturally I got the wife to do this, as she is an expert stirrer.... When we got to the end, we did a two minute stir, then thought it would be a really good idea to let it sit for 10mins to let the bubbles rise out. It was going really really well - the bubbles were rising to the surface nicely, away from our little tap....

26003

Cue minute eight. The tub starts to look a little strange. Cries of "Oh Shit! The pots melting!!" come from the other side of the garage as the tub starts imploding and the epoxy level rapidly rises towards the rim of the bottle. Thankfully, we already had our gloves on and at the ready, so taking the very hot bottle, I swing it over to the frame and start the first pour by hammering on the tap's release button....

Of course, the damn thing had already jammed shut. At this point, theres nothing for it but to up-end the bottle and start pouring from the top. Bubbles are being created everywhere, and there are a lot of fumes being released into my unsuspecting garage. I think they were mostly melting plastic fumes... but they could also have been fumes from the rapidly curing quatermass.

Somehow, we managed to get the epoxy poured (taking shifts on who could hold their breath in the toxic air for the longest, the other running outside for some palatable air). I managed to go round 3/4 of the frame with a scribe and poke a few of the biggest bubbles before it became too gelled to continue, but most of them have left small craters. I'm quite sure the last 10cm or so hasn't been able to level before gelling.

Heres the good bit (that was poured first and attended to) - We then decided to coat everything but the bridge in clingfilm, so that nothing can fall into it, and then we retreated putting the mangled bottle in the emergency bucket.

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Videos of the final result to follow....

[AndyUK]

https://youtu.be/2-7Gt-XMFd4

https://youtu.be/UW6zPT2v4nc

[Scustom]

Hi Andy,already sent you a pm about what may happened,and here is the answer from west system site:https://www.westsystem.com/instruction-2/epoxy-basics/epoxy-chemistry/
Controlling Epoxy’s Cure Time

In warm conditions use a slower epoxy hardener, if possible. Mix smaller batches that can be used up quickly, or pour the epoxy mixture into a container with greater surface area (a roller pan, for example), thereby allowing exothermic heat to dissipate and extending open time. The sooner the mixture is transferred or applied (after thorough mixing), the more of the mixture’s useful open time will be available for coating, lay-up or assembly.

[AndyUK]

Thanks to both Scustom and routercnc, think you have both nailed it, the combination of waiting for bubbles, and mixing in a tall narrow container allowed the exothermic reaction to spiral out of control.

I've got a new set of Epoxy on order, I've spent the evening clearing off the crap pour and the mountain of silicone, and will try again soon. Thankfully the frame hasn't suffered and can be used again with a fresh set of silicone. Expensive mistake but hey, we all screw stuff up every now and again!

This time, I'm going to make the amount in three mixes rather than 6, and in a wider tub. I'll then transfer to another jug with a taped up hole in the bottom, and immediately pour onto the rails.

Sent from my SM-G950F using Tapatalk

[AndyUK]

Living near Southampton has some advantages - fast epoxy delivery!

Poured again tonight, and fingers crossed, I think we've nailed it.

We mixed in a very wide tub - an old decking screws container. Did the entire 1.3L in one go, adding 175g 105 and 50g alternatively, mixing a little inbetween. The mixup process took about 6.5mins start to finish, then did another final mix for 1.5min until no streaks were visible and the colour was entirely uniform. We then transferred to a 2L ice-cream tub which had two 8mm holes in the side at the bottom corner taped over (we measured the flow time of 0.5L of water through a 5mm hole, and decided it needed to be 8mm. Found about 20seconds for water through 8mm - so decided that should be a nice 1-2min pour of the epoxy which worked well. Second hole was a backup and never used.

The pour went really well - managed to time it so that the fizzy bubbles at the end of the tub landed in the centre of the bridge. Surface looks glassy smooth - had two 1-2mm bubbles on the main beams, but managed to easily pop them with a scribe. There are some very small <0.5mm bubbles in the epoxy itself throughout - but I'm not too worried about these as they're so small.

Weather looks good for the week, not dipping below 14 degrees, and the garage was 23 degrees when we poured. I haven't used any artificial heating yet - the plan is to poke the bridge section on Sunday, and if its still not gelled, we'll start heating then.

Thanks for the help everyone... fingers crossed!!

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[AndyUK]

Lets talk cabinet layout for a moment or two.

I've just started a thread about tidy wiring (here (http://www.mycncuk.com/threads/12956-Tidy-Cabinet-Wiring?p=110025#post110025)) so I'm currently still deciding how to do my wiring channels (shown as green in the annotated diagram) as neatly as possible, but I think I've got a plan for the overall layout.

26184 26185

As you can see, I've silently been buying more and more electronical bits (psst... please don't tell the wife how much this stuff costs...). My plan is to have the drives vertical in the bottom right with heatsinks facing each other, right by the inlet fan. The outlet fan will then be at the top of the case directly above the VFD (or possibly top left facing out sideways... which might be better from a water point of view if the roof were to leak (a real possibility in my garage...). My thinking here is that they'll have the most urgent cooling need in the cabinet, so they get the coldest air first. I'll probably put the two X drives at the top, as they'll be working the hardest and I don't want their heat transferring to the Y and Z drives - Who knows if that logic makes any sense or not? Maybe it should even be the other way around...

This position allows the driver outputs to get straight out through the GX20 connections on the base, and the input signals can come directly in from the right hand edge (as shown) of the UB1 where all the step and direction signals come from. The drive PSU is a little awkward here, but shouldn't be too far for the power to get to the drives from the right hand side of the PSU.

The GX16 connections (limit switches, homing switches etc) also come in at the bottom and can go straight up to the UB1.

My plan is for mains to come in bottom left, skirt behind or up the side of the PSU, and into the distribution/fuses area. From there each mains device will connect via individual EMF filters and relays/contactors/big on off switch as required.

Finally, theres a low voltage section up top. My plan for this is to have the safety / 24V circuits up here. This is where the control panel will interface - I have a selection of LED buttons for this, each with a specific function in mind, but I still haven't decided exactly where the panel will go (having a glass fronted cabinet is nice, but not so many options for things like buttons!).

Anyhow, I hope that either this post is helpful to others, or someone can point out any glaring problems or things I've not thought about! Update on the mechanicals soon - there is currently paint drying, and the garage has been even messier than usual in the last few weeks so I've not gotten around to photographing and writing up the most recent developments.

[AndyUK]

I promised an update on the frame - here she is in all her badly painted glory!!

Since the last photos, I've

Faired the edge of the epoxy into the frame and repainted the box sections.
Filed off the meniscus along the edges and at the ends.
Marked drilled and tapped the epoxy for the rails.
Roughly aligned the rails for parallelism
Checked the levelling with a precision straight edge - more details below.
Thrown the gantry on the rails - it glides super smooth (and made me very happy!)
After getting happy about that, I then got very sad. Turns out my steel frame is a bit of a rhombus! When I bring the gantry to one edge, it hits the end of one rail about 3-5mm before the end of the other, and the opposite occurs at the other end. I don' t think this will actually affect anything, except perhaps my pride...
I then did some more milling, making my Z and Y nema 23 motor mounts. That was fun. :)
Did a rough assembly - All I need now to make the Z and Y axis move under their own power are the belts which are on order. It was nice to be able to measure the distances between pulley centres physically rather than just in CAD.


The rails both show the same trend, they're high at the ends and low in the middle with an error of about 0.05mm - I'm sure this could be better, the epoxy still set relatively quickly, so I'm sure there are improvements to make. It could be that I just haven't filed down the ends of the epoxy enough and they're slightly propped up at the ends, but its 'close enough' for me at this stage. The other consideration is that this value is the stated accuracy of my straight edge, so optimising it now seems counter productive. I will probably come back and shim the rails, but I'm keen to do a 'proof of concept' and am aiming to have the machine cut something by Christmas.

I've noticed that the Z axis isn't as smooth as the others; I think it might be the alignment of the ballscrew vs the rails, I've discovered that my design is a bit of a nightmare to try and measure the alignment between the two, because the rails and the screw are attached to different parts. The other thing it might be is that the Z axis is the only one thats had a load of EP2 applied - does that typically increase the resistance on the screw? I can turn the pully by hand no problem, but you can feel that it has more and less resistance at different ends of the travel, which is something I don't feel on the Y. Any hints or tips?

The other problem I'm now considering is how to check the axis are perpendicular... can anyone point me in the right direction? I think Boyan mentioned needing two precision squares to align properly... I can see why you'd need one, but two?

Thanks!

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[Nickhofen]

If the diagonals of the x (long axis ) are equal, then the axis is orthogonal,start from this !
Then bring the Y axis at a point and measure with a square, that you know it is at true angle.
How you know that you square is really a square?
Check this video:
https://m.youtube.com/watch?v=gDh-E5xhm0o
If your square is not as it should ,do not through it away,check on YouTube how you can make it square again.
Good luck!
And remember any precision tool that is fall on the ground or it it is banged on something hard,stops to be a precise any more,it needs re calibration.

[NordicCnc]

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Hello. Looks really good! Is there any benefit if looking a how rigid the machine is by having the gantry rails on top and at the bottom, compared to mounting both on the same side?

For example if we compare these 5 options, which one is the best for rigidity?


Both rails on the spindle motor side of the gantry, ballscrew in between rails.
Both rails on one spindle motor side of the gantry, ballscrew in between on the opposite side.
One rail on the spindle motor side side, ballscrew on the same side and the other rail on the top of the gantry.
One rail on the top, one at the bottom and the ballscrew on the opposite side of the spindle motor side.
One rail on the top, one at the bottom and the ballscrew on the same side as the spindle motor side.

[AndyUK]

Both rails on the spindle motor side of the gantry, ballscrew in between rails.
Both rails on one spindle motor side of the gantry, ballscrew in between on the opposite side.
One rail on the spindle motor side side, ballscrew on the same side and the other rail on the top of the gantry.
One rail on the top, one at the bottom and the ballscrew on the opposite side of the spindle motor side.
One rail on the top, one at the bottom and the ballscrew on the same side as the spindle motor side.


See the Beginner Moving Gantry Design Thread (http://www.mycncuk.com/threads/9082-Beginner-Moving-Gantry-Build-Read-This%21)

[NordicCnc]

Thanks for that link!

By the way do yiu have a youtube chabbel? I saw a very similar if not the exact same build. Joe Harris is the name of the channel.

Skickat från min SM-A530F via Tapatalk

[MikeyC38]

Hi Andy. Didn't see an answer to your question about VFD harmonics. I fitted an emi filter from the mains to the input of my control box using one of these https://www.ebay.co.uk/itm/EMI-RFI-Filter-AC-250V-10A-CW1D-10A-T-Suppressor-Power-Line-Noise-Filter-new/172353686432?hash=item2821148ba0:g:7DUAAOSwYIxX54F f&redirect=mobile . This plus star farthing all the shielded cabling eliminates the problem I had when the vfd was running (false estops). Also mounted my vfd external to the controller again to avoid electrical noise getting through.

[AndyUK]

Hi Andy. Didn't see an answer to your question about VFD harmonics. I fitted an emi filter from the mains to the input of my control box using one of these https://www.ebay.co.uk/itm/EMI-RFI-Filter-AC-250V-10A-CW1D-10A-T-Suppressor-Power-Line-Noise-Filter-new/172353686432?hash=item2821148ba0:g:7DUAAOSwYIxX54F f&redirect=mobile . This plus star farthing all the shielded cabling eliminates the problem I had when the vfd was running (false estops). Also mounted my vfd external to the controller again to avoid electrical noise getting through.

Hi MikeyC,

Thanks for the tips! I bought three of those from Ali Express a while back; I chose three because I placed them after the mains input and before each main component (VFD, 24V PSU, and Drive PSU) - hopefully so that noise from each didn't affect the other, because it had two filters to pass through, if that makes any sense. When it came to wiring them though, I realised the IEC cable wasn't what I wanted (being that theres three inside the cabinet), so I got some alternatives with spade connectors on. Something like this (https://www.aliexpress.com/item/32635753265.html?spm=a2g0o.productlist.0.0.b7eb7a3 8WuGdej&algo_pvid=28e10bc4-3fef-403c-8bc1-2885b629f83d&algo_expid=28e10bc4-3fef-403c-8bc1-2885b629f83d-6&btsid=e61e5ce9-1528-46cb-88d9-6cdd61ee02e3&ws_ab_test=searchweb0_0,searchweb201602_10,searchw eb201603_55).


Thanks for that link!

By the way do yiu have a youtube chabbel? I saw a very similar if not the exact same build. Joe Harris is the name of the channel.

Skickat från min SM-A530F via Tapatalk

Yep - If you look at the start of this thread, you'll see its heavily based on Joe's build. I'm a bit more camera-shy though, so haven't gotten on the old youtube.

In other news, I'm slowly but surely wiring away. Taking a little time over it - life has become rather busy at the moment with all the other distractions :) I'll try and post a picture of current progress sometime this week.

Thanks,
Andy

[JanBo]

Hi Andy. That's a very nice layout on your machine - it's certainly strong enough to handle aluminium. Grats on the build JanBo

[AndyUK]

Heya All,

Promised an update, so here we go!

Wiring is in progress in the living room - oh my life there are a lot of wires on these things. Trying to keep it as neat as possible, but certainly not an easy task. Slightly concerned about how close the UC300eth is to the VFD; but it leaves room for a mini ITX sized PC in the future if I want to move in that direction, or a fifth motor driver for a forth axis.

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I've also been designing my gland plate - the plan is to have it detachable from the inside (as well as the outside) so the plate can be taken out with the entire electronics panel for reworking in the future if required. To do that, my plan is to put a stainless steel plate on top of the current gland plate. Apparently I took the layout photo the opposite way around though!

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In other news, my X Axis ballscrews are on and connected - the aluminium stand-offs for the ballscrew mounts are temporary, but they are the correct thickness. There's a certain aspect of 'I'll make that better later once its working' going on here... ;)

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I've also ordered an aluminium block to try out water-cooling those motors inside the frame. Hopefully it should fit right in, and do the job nicely - but we shall see. My next job on the mechanicals is to make the X axis motor mounts, but that needs another day on the old bridgeport.

[AndyUK]

I can see why everyone posts a video when they get their E-Stop circuits working for the first time :) Its quite a nice amount of clicking and clunking going on.

Until you decide to leave the panel running for five minutes with the motor driver supplies latched in.

And then you smell smoke.

And realise that the 24V contactor you purchased has the confusing symbols "50/60Hz" following the 24V designation...

Oh well. Off to find myself a new 24VDC contactor... ;)

That video may have to wait - although I can attest to the fact that if the contactor short circuits, the PILZ will cut the power to it pretty sharpish.

[Crunch]

Hi Andy
If it makes you feel any better I did exactly the same thing,
Whoops..

[AndyUK]

Haha it does! Thankyou :)

In all seriousness, hopefully by sharing the woopsie moments I can prevent someone else doing the same in the future. This is my first time purchasing and specing out these types of components, and on the rapid electronics page and datasheet there is only a single line which alludes to the fact it's an AC coil; "for AC switching" which I took as "for switching AC loads" - I've never seen 24VAC used for control circuitry before, but clearly it's the default.

[CharlieRam]

Haha it does! Thankyou :)

In all seriousness, hopefully by sharing the woopsie moments I can prevent someone else doing the same in the future. This is my first time purchasing and specing out these types of components, and on the rapid electronics page and datasheet there is only a single line which alludes to the fact it's an AC coil; "for AC switching" which I took as "for switching AC loads" - I've never seen 24VAC used for control circuitry before, but clearly it's the default.+1 I did the exact same thing on my build too!! [emoji85]

Sent from my SM-G920F using Tapatalk

[Kitwn]

I've never seen 24VAC used for control circuitry before, but clearly it's the default.
Andy, you're showing your age (or lack of it:tennis:) 24v AC dates back to when control systems were relay based (eg the 1960's Marconi BD272 250kW radio transmitter). AC is better for 'wetting' relay contacts and obviously does away with the expense of a rectifier and smoothing.

Kit (aka Old Fart)

[AndyUK]

Haha - well, I'm glad I'm not the only one. It has prevented me smoking my other relays, which were also 24VAC... and I've managed to find a replacement 24VDC contactor at work which was for a machine we removed a long time ago and otherwise going to waste.

I was born before the Berlin wall fell, but not by much - so I'll have to take your word on the 60s! :)

Now that the contactor is working as expected I can share my E-Stop circuit video as promised! I appreciate its the same as everyone elses, but hey, its a progress milestone. I also couldn't resist playing with the LED switches - the Red is E-Stop reset, the Green is the motor drive power latch, and the Blue are auxiliary switches for water pump/air solenoid. There will also be a yellow momentary limit OVR, but I haven't gotten around to installing that one yet. The plan is to have a control panel on the front of the machine rather than at the electronics box - so at the moment everything is wired up to these terminals at the top of the plate, and then I'll take them to the panel with a couple of 7-core CY cables.


https://youtu.be/3QmBGxghq9s

I've also got the signals for the motor drivers wired in, and I've connected up the Z axis motor just to test the communication with UCCNC, so theres a video of that in the mix as well - enjoy! You'll see the Y and X drivers instantly fault out - the UC300 is reading those fault signals, however they're currently configured the wrong way around (I'm waiting for my RJ11 crimper to reprogram the drivers). The fault signal wiring has changed somewhat from my last published schematic; my plan is to use the OSSD on the UB1 to enable or disable the drives, so that a fault signal on one drive causes all of them to stop - but again I need to program the drives to listen to the enable line.


https://youtu.be/U-uzLlwuTG4

The proximity switch has also been tested, although my trial one was an NC 2mm NPN - 2mm is a bit small, so I'm planning to try a 4mm next. I'll probably use proximity switches for both limits and homing, but thats still up for debate.

[Crunch]

Looking good. It's nice when things start to move.
I've just finished mine. Just running a few codes through it not cutting anything to see if it gets any false stops.
It doesn't look like you will be long before it starts moving it's self.


Sent from my SM-G900F using Tapatalk

[Kitwn]

I was born before the Berlin wall fell, but not by much - so I'll have to take your word on the 60s! :)
I was born before the Berlin wall was built, but not by much, so whilst I saw the 60's I didn't learn about their control systems until the 80's.

Nice work on the controller. Yours is much neater than mine!

Kit

[Nickhofen]

Andy have you post a wiring somewhere for your control box?

[AndyUK]

If you're after the wiring diagram, there is an early version in post #37 (page 4 for me). It needs some updates though - most notably it needs 2k resistors on the enable + lines else it's a good way to blow the EM806, and it doesn't have the UC300 disabling the drives through the OSSD because this is new for me and still needs testing.

My plan is to update the diagram and post soon :)

[Nickhofen]

Awesome,thanks.
I am struggling to find time to continue with my build and it is very helpful to have a wiring to start with.

[AndyUK]

Here's the current version of the circuit diagram - don't take it as gospel, check every connection against the datasheet of both things you're connecting as you go (that's how I realized before it was too late that +24V to the drives on the enable without the 2k resistor was a bad idea). I haven't made all these connections yet, so that's why I'm warning everyone!

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Having said that - let me know when you find a mistake ;)

[Doddy]

Andy, quick question - the schematic suggests the 4x2k resistors are commoned, unless you mean to draw a bus supply (yellow line to EN inputs on the drivers) - is that correct?

I'd also protect the LED indicators from back emf from the relay coils - LEDs don't take reverse polarity well (unless these or the relays already have protection?)

[AndyUK]

Thanks Doddy -

I'm being very economical with my lines - the resistors arn't commoned at all - I'm just trying to say that it doesn't matter which line goes into which input, and I didn't have room to draw them all individually, however I'm constantly rejigging it so will try and fix that for clarity.

I don't think the LEDs are protected - good point. Is that just a diode across the LED in the opposite direction to allow the back EMF to flow past it? Haven't wired those relays yet - they're on order (as the initial ones were 24VAC).

Edit - Diagram updated above.

[Doddy]

Understood about economy of lines, I’d originally interpreted the schematic a described but there’s other examples of 1:1 mapping which was enough to ask the question.

Led protection?, what you describe is perfectly good. I’d have thought to suppress directly across the coil but across the led works as well

[Nickhofen]

Good point about the diode protection from back emf, I have placed mine directly on the relay to protect the coil from back emf.
What do I miss about the resistors on the enble+ line? I mean obviously the resistors will reduce the current flow but how much is the current that will run if the resistor is not there and how much is acceptable?
I have the AM882 that is why I am asking!
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[AndyUK]

Good point about the diode protection from back emf, I have placed mine directly on the relay to protect the coil from back emf.
What do I miss about the resistors on the enble+ line? I mean obviously the resistors will reduce the current flow but how much is the current that will run if the resistor is not there and how much is acceptable?
I have the AM882 that is why I am asking!


The AM882 has the same logic signal current specifications as the EM806 (hardly surprising considering they're basically the same thing, but I thought I'd check). 7-16mA with a nominal of 10mA. They've designed it for a 5V signal, so I expect the internal resistance is ~500 Ohms (because that's what gives 10mA for 5V). V=IR, so I = 24V / 2.5kOhm = 9.6mA. (I used 2.5kOhm because my 2k resistor plus 0.5k internal).

Or, you can just read the diagram in the driver's manual about the connection where it specifies in a small box below that you need to add a 2kOhm resistor if the signal is 24V, which is a far simpler way to do it!

We don't need the resistors on any of the other lines - The pulse and direction outputs from the UB1 are 5V signals, and the alarm signal is an output not an input, so it has different specifications.

[AndyUK]

Looking at limit and home switch placement... I've kinda put this off as long as possible, but here goes.

The idea is to use proximity switches for both - and to use two travelling switches on Z and Y, then 3 fixed switches on each X axis.

Unfortunately because I've only thought about these late in the game, they're a bit shoe-horned in - I'd appreciate any comments or suggestions... I feel like I've tried about a million different placements.

I remember reading somewhere that proximity switches should be triggered by a sloped target - I'm not sure if I've got my targets sloped in the right direction, or even what angle to aim for.... Some advice would be awesome!

Zoomed Out for Reference:
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Z Axis:
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Y Axis Limit
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Y Axis Home + Limit
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X Axis Limit
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X Axis Home + Limit
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[AndyUK]

I've also posted a few wiring questions over on CNCRoom - my hope was that they'd be able to help more with the UB1 specifics, but seems to be drawing a blank so-far. If anyones interested, the post is here: https://www.cnczone.com/forums/uccnc-control-software/392066-cnc.html

[JAZZCNC]

Why 2 switches on each axis if they are traveling.? The point of having traveling switches is to lower the number of switches.

All you do to use 1 switch is set the same input number for each Limit IE: X Lim (++) = Input 1 and X Lim (- -) = 1. X Home = 1. Then when Switch sees the target at each end it trips Both Limits, It doesn't matter which Limit shows on screen all that matters is that it trips when triggered.
When it's homing it ignores limits and looks for the Switch trigger.

Regards Sloped Target then it's not needed for proximity switches. Just needs to see the metal target, However, it is better if switch passes over the target rather than butting up to it.

Also, you don't need 3 switches on Each X-axis. Only need 3 Switches for Both sides. X2 only needs a Home SW it doesn't need Limits the other side deals with Limits.

[AndyUK]

Why 2 switches on each axis if they are traveling.? The point of having traveling switches is to lower the number of switches.

All you do to use 1 switch is set the same input number for each Limit IE: X Lim (++) = Input 1 and X Lim (- -) = 1. X Home = 1. Then when Switch sees the target at each end it trips Both Limits, It doesn't matter which Limit shows on screen all that matters is that it trips when triggered.
When it's homing it ignores limits and looks for the Switch trigger.


Thanks Jazz, didn't realise you could use the same switch for both limit and home! I can see two advantages to using two switches; it means the limits can form part of the safety circuit, and I'm not sure I like the idea of needing software to guarantee a stop.., and on the off-chance I have a faulty home switch or messed up homing sequence, I'm still protected (which is hopefully the only situation that I'm headed towards the limits blindly).

Clearly needs more of a think :)



Regards Sloped Target then it's not needed for proximity switches. Just needs to see the metal target, However, it is better if switch passes over the target rather than butting up to it.

Cool that saves some shaping.



Also, you don't need 3 switches on Each X-axis. Only need 3 Switches for Both sides. X2 only needs a Home SW it doesn't need Limits the other side deals with Limits.

Good catch - clearly not with it yesterday :) That is what I've drawn in the circuit diagram, just wasn't thinking straight when playing with CAD...

[JAZZCNC]

Thanks Jazz, didn't realize you could use the same switch for both limit and home! I can see two advantages to using two switches; it means the limits can form part of the safety circuit, and I'm not sure I like the idea of needing software to guarantee a stop..,

It depends on how you look at it.? Limits are not really a Safety or E-stop situation, they are a positional error not really an emergency situation.
For instance, the most common limit trip isn't because machines run off on its own accord but rather because you jogged into them or set Work zero too close to limits. In which case the Software will warn you and won't allow when soft limits are turned on. However, having to reset the drives every time you jog into a limit soon becomes a pain and on small machines, this happens a lot when first learning.
Also your not actually relying on software with the UB1 or better controllers because the controller's hardware actually stops the motion and then informs software it's happened.

[AndyUK]

Spent the day thinking about Jazz's suggestions - decided to listen to wisdom :)

The clincher is that it really simplifies the circuits, and I don't have to now work out how to connect the proximity switches I have (NPN NC) in series - I can now just run each back to the controller and have enough input pins to deal with it.

Leaves me needing 5 proximity switches in total - a Positive X limit, two Negative Xs (one each side, doubling as the X homes), a Y and a Z (each doing triple duty). You can see most of them and their trigger plates highlighted in the diagram below.

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[JAZZCNC]

Spent the day thinking about Jazz's suggestions - decided to listen to wisdom :)

The clincher is that it really simplifies the circuits, and I don't have to now work out how to connect the proximity switches I have (NPN NC) in series - I can now just run each back to the controller and have enough input pins to deal with it.

KIS approach works best every time. I've built dozens machines that use this setup without any safety issues. The only time I use separate limits is when using Servo motors because they do just take off when Encoders fail.

[AndyUK]

So, I've had a very frustrating evening trying to get my EM806s to talk to my computer running the Protuner application.

After about three hours of getting 'unable to connect to drive' messages, trying every version of the software known to man, every pin combination I could think of, and every port setting I could muster, on windows 10, Mac OS, and windows 7, I was having absolutely no luck getting my USB to RS232 FTDI adaptor to work. I finally remembered that the old PC i'm using for the CNC has a physical com port on it, and within two minutes everything is working perfectly.... I suppose it counts as a success if it works eventually right?

Anyhow, all my drives are now programmed with the opposite settings for fault output and enable, which means that the fault output is NC, and the drive is only enabled with a high output signal from the UB1's safety circuit. Therefore, if the Spindle or a single drive faults, the drives remain powered but disabled.

The anally retentive label fairy has also visited; I realised whilst wiring up the lines to the control panel I had the potential for 24 terminal blocks each doing different things with no labels, and although I have diagrams and terminal block numbers.... didn't feel like in a years time I'd remember what the hell each one did. Out came the 3D printer, and I printed some stages which fit over the terminal blocks and allow me to place labels on them. I also printed some blanking plugs for my spare GX20 and GX16 holes on the gland plate.

If you also feel like the fairy needs to visit, I've put the files up on thingiverse (https://www.thingiverse.com/thing:3972884).

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[AndyUK]

Time for the Sunday night update!

Electronics have been relocated to their cabinet - everything in there is wired up and done (... I think...). I'm waiting on a couple more bits for the gland plate which are delaying things somewhat (I can't really solder the connectors on until the gland plate has all the right holes in). Thinking a 300mm deep cabinet may have been slightly overkill, but initially I was very concerned about how far the VFD was sticking out.

I've also sorted out the water coolant tank - rather a nice skip find! I've put my water pump in that bottle, just needs wiring up and re-sealing.

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Next up - the home/limit switches. I've 3D printed holders for them, and mounted two of the three X switches. I plan to silicon that hole to prevent the cable rubbing with vibration once I'm happy with their locations.

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And last but not least, I've been working on keeping the wiring on the machine tidy. I 3D printed a set of clips to route the wires from the X Right side across to the wall side of the machine, and plan to use this technique all around. This is one of the clip prototypes:

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And here they are in action:

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In order from bottom to top, this is the Motor wire, then the water cooling for the motor, then two limit switches. Quite fond of these :)

In other news, I've managed to find some cable chain for Z and Y from another skip, and will order the X axis cable chain tomorrow. You might also spot that I've added in the holder for the Y axis cable chain.

I'm having trouble finding some U section perspex to act as a finger guard on the X right hand side over the ballscrew - if anyone knows a company or person that might be able to help with a custom extrusion or who can bend this, it would be ace. I'd really like to keep it transparent, but keep little fingers out...

[Nickhofen]

Nice and tidy,good job Andy!

[AndyUK]

Small Circuit Diagram Updates:

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I've added an extra control line to the spindle to enable the reverse spindle command. Don't know if I'll ever use it, but may as well wire it up while I'm here. I've also added the Z probe, and control line labels, which will probably only make sense to me, but hey, now its here as a backup for me in years to come!

Planned Spindle Parameters with my setup:

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These are basically as per the sticky thread, but I've customized the multi-input and FA/FB/FC functions, and chosen other parameters for my setup (and added labels for anyone who can't be bothered to look them up in the manual!!).

Progress otherwise has been generally quite slow having been away for a while...

I've finished the gland plate wiring and soldering, and am now working on the cable chain arrangements before finishing up the GX20 plugs on the motors and spindle. I've rescued some old Igus chain from work, but it didn't have any ends, and they're no longer in production, so I'm 3D printing my own mounts which is taking a few iterations.

With the gland plate finished, that is essentially everything in the cabinet done, so I powered it up for the first time in place the other night to test communications etc (PC is on the other side of the garage, had some fun with evil CAT5 cables, panel mount CAT5 joiners, and a apparently one of my crimpers is dodgy). The airflow through the cabinet sounds proper industrial... :) That was then followed up by the PC's graphics card dying, and ironically a licencing issue with UCCNC exactly like Voicecoil's that magically fixed itself after about an hour... I genuinely have no idea what I changed. Fun week.

Bridgeport time has also been limited, so I have one of my x-axis motor mounts and am hoping to mill the second this weekend. The water-cooling blocks are in and waiting, so I'll try mounting the motors in the steel tubing as per the design and see what burns out first :)

[JAZZCNC]

PD 14 and PD15 are too low you will get overvolt or over current trips at higher rpm because it cannot get to commanded speed in 2 second or stop spindle in 1 second so it dumps in a load of volts/current to try get there but cannot possibly do it.

Set PD14=5 PD15=10 for safe settings. Then if your not quite at full RPM before G-code starts moving set an M3 delay in the spindle settings.

[AndyUK]

Hi All,

So, I thought I had the machine all ready to make its first self-powered movements this evening, however I've stumbled!

I'm pretty sure the problem is that the drives are not enabling, because they worked before I reprogrammed the enable to be active high rather than active low, so one of the things I'll do to test is reprogram a drive enable to be active low again and retest.

I thought I'd throw this out to people to see if you can see where I've gone wrong. The drives are wired as per the EM806 manual (below) and my circuit diagram two posts ago.

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So, each drive has a line from +24V on the UB1 to ENABLE + on the drive via a 2k ohm resistor. The ENABLE - lines are then commoned, and fed into the OSSD output on the UB1. This is the output of the safety circuit, which I can override with a button (so I know the cause isn't limits etc).

The UB1 manual says this about the outputs:

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And lists the OSSD as just another output that is controlled by the safety circuit:

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My thoughts were, that when the output is off (i.e. safety circuit broken), no current can flow through the enable optocoupler, so its a logic low. When the output is on current can flow, logic high, drive enabled.

The drives target 10mA on those optocouplers, so 40mA approximately should be within the 70mA sink of the output.

I know the OSSD output is doing its thing because I can see the LED come on when I press the override.

Have I missed something?

[Neale]

My thoughts were, that when the output is off (i.e. safety circuit broken), no current can flow through the enable optocoupler, so its a logic low. When the output is on current can flow, logic high, drive enabled.


I haven't ploughed my way through the UB1 manual, but in general terms it looks like the internal "switch" in the UB1 shorts the pin to earth (in which case current can flow) or not, in which case no current flows. What might be causing confusion is that when the switch is on, current flows, and the output voltage on the pin is more-or-less at earth potential. When the switch is off, the output pin is high voltage (as the resistor and enable output path on the driver form a pull-up circuit). So is your logic the wrong way round? :Low and high usually refer to the voltage on the pin, not current flow.

[AndyUK]

Yeah that thought did trouble me too...

I didn't notice the drive working when I wasn't overriding the safety circuit, but it's also possible that in that condition the UB1 won't send the step signals.

I need to dig up some example circuit diagrams where people are switching the enable lines of the AM882 or EM806.

[Neale]

I use EM806 and I switch the enable line. Offhand, though, I can't remember exactly how, but I think it's a direct connection from a relay contact on my safety relay. Too late tonight but I'll try to sort out some info tomorrow. I know that my EM806 are in the default "disconnect to enable" mode as I've never tried to reprogramme them.

[Kitwn]

Optocouplers work a little like elctromechanical relays: When you apply a voltage across the input terminals the output terminals are connected together. In practice most couplers contain a LED which lights up to turn on an open collector transistor. The most common circuit implementation connects the LED cathode and the emitter of the transistor to ground. Your external circuit will normally include a pull-up resistor between the open collector and the positive supply so the output voltage (the collector of the transistor) is high until pulled low by a positive voltage applied to the anode of the LED. The device therefore acts as an inverter in this configuration.

There is no reason why the collector of the transistor cannot be connected to the positive supply and a pull-DOWN resistor connected between the emmiter and ground. The output is now the emitter and the circuit is non-inverting. As long as the collector is allways positive with respect to the emitter the device will work.

Simillarly the anode of the LED can be connected to the positive rail and the cathode pulled low to turn it on if that suits your circuit voltages.

All clear as mud?

27268

The stepper controllers I have used have all deaulted to 'enabled' if the enable input is left unconnected. You could test the rest of the beast's function this way.

Kit

[AndyUK]

All clear as mud?

The stepper controllers I have used have all deaulted to 'enabled' if the enable input is left unconnected. You could test the rest of the beast's function this way.

Kit

Thanks Kit, I've read through a few times and I think that talley's with my understanding. The problem is, I can't get to the collector or emitter in the drive, and only the collector on the UB1, so I don't have a lot of wiggle room to add pull up or down resistors?

It definitely all worked before reprogramming the drivers, it's just a hassle now everything is in place, but that's the first step.

[JAZZCNC]

Are the drives powered up when your trying to enable them.? If so it should work if you have switched the Active state to High in the drive it's self and pulled the Opto high. To test the drives then just reset Active state and disconnect the enable.

[AndyUK]

Yeah drives have power, and I can see the LEDs on the UB1 flashing to indicate the Step and Dir pulses are sent. Unfortunately I'm away from home for the weekend so testing is delayed!

Have just found this from vrasak himself (post #3) - so perhaps I'm just confusing my logic states as per Neale's suggestion, and really the drives just need to be configured active low. Vrasak refers to the need to switch the fault state, but not the enable, which is suggestive :)

https://www.cnczone.com/forums/uccnc-control-software/379474-cnc-forum.html

[Doddy]

Andy,

I think you understand a fair bit on the old electronic side. I was casually browsing this thread and one thing is niggling me. Opto isolators typically have a low CTR - usually significantly less than 1, often less than 0.5. That does mean that cascading optos is going to end (eventually, depending on CTR and number of optos in chain) with the latter optos not switching effectively. Really, the opto should be switching a high-z logic device rather than the relatively high current LED input on the successive circuit.

You link a rating of the output at 100mA - that /could/ just be the Ice(max) for the PT in the opto, rather than an actual expected switching current (reading the 4n25 data sheet this is the case).

I'm not suggesting this is your problem, but bear it in mind and measure the switching voltages along the opto-cascade,

[Kitwn]

You learn something new every day!

A scan of the RS catalogue shows you can get inexpensive devices using Darlington output stages with CTR values as high as 50 and more if you have the luxury of designing the circuit yourself, though they have a higher sturated output voltage. Problem is we're often dealing with couplers already installed in larger devices and cannot choose.

Pull-up/down resistors are often already included in many devices, it being a very bad idea to leave logic inputs to float as the mood takes them. This is how the common "enabled if left unconnected" principle is implemented.

[AndyUK]

Andy,

I think you understand a fair bit on the old electronic side. I was casually browsing this thread and one thing is niggling me. Opto isolators typically have a low CTR - usually significantly less than 1, often less than 0.5. That does mean that cascading optos is going to end (eventually, depending on CTR and number of optos in chain) with the latter optos not switching effectively. Really, the opto should be switching a high-z logic device rather than the relatively high current LED input on the successive circuit.

You link a rating of the output at 100mA - that /could/ just be the Ice(max) for the PT in the opto, rather than an actual expected switching current (reading the 4n25 data sheet this is the case).

I'm not suggesting this is your problem, but bear it in mind and measure the switching voltages along the opto-cascade,

Hi Doddy,

Thanks - that is quite high praise, but I'm still very much stumbling my way around so don't assume too much!

I hadn't really considered the CTRs of the optoisolators, however is this relevant if I'm effectively connecting each drive in parallel with oneanother? My intuition is only really concerned about the fact that I have the Optoisolator from the drive, and then the one in the OSSD output which as I understand is effectively acting as a transistor to ground. Upstream of the drive is merely the current limiting resistors and the +24V rail. My ~40mA came from the sum of 10mA per drive based on the current limiting resistors, and if the CTR<1 then I shouldn't have damaged anything staying under 70mA.

I suspect I've totally missed the point here though :) Please educate me further!

[AndyUK]

Managed to reprogram one of the drives last night (its a faff now they're in the cab) to be Enable Active low, and instantly was able to get my first self-powered movements on that axis (huzzah!! - I'll post a video once I have all three axis working and this enable issue resolved, because as usual the garage is a tip).

I didn't change the enable wiring, and noticed that the drive was enabled whatever happened (one of the other unconnected drives faulted out which dropped the OSSD output, but it had no effect on the active low drive). Therefore, the problem isn't that I've got my logic states messed up, or at least that's not exclusively the problem.

My next step is to try experimenting with wiring setups to try and get the enable functioning. First I'm going to try Vsarak's two suggestions above, first utilising the 5V rail and another output (schematic B), and second, using a differential connection from a spare axis output (schematic A).

The third step would be to try the NPN connection recommendation in the EM806 manual (which I now realise is effectively what I've been trying to do). The only difference here is that the resistors are placed on the ENABLE - line rather than the ENABLE + line - would that really make a big difference? See attached.

27311

[Doddy]

I suspect I've totally missed the point here though :) Please educate me further!


I'm trying not to mis-direct this thread (tangent?, what tangent...), but to explain my logic....

If I redraw your schematic (lesson #1, "Eagle" is not good for this)

27314

and zoom into a bit of text that I torturously added

27315

If you /assume/ that the opto-isolator on the UB1 OSSD output has a forward current through the LED (I1) of 10mA (not unreasonable, and likely a design goal). Also, /assume/ the CTR is 0.5 for that device. That means that the switching current (Iossd) would be I1 * CTR = 5mA.

Now, Kirchoff's law says basically that the sum of the currents at a node equals zero. So, if 5mA is flowing into the OSSD input, then the sum of currents through the 4 separate '806 drivers must also equal 5mA. Give them the benefit of the doubt and say that all '806's are created equal, then your forward current through each '806 LED is that 5mA, divided equally by 4, or 1.25mA. Not the 10mA that you believe you have. Then you're at the mercy of the circuit design in the '806 behind the internal opto-isolator. That 1.25mA is multiplied by the local CTR and further diminished. Also, the CTR is impacted by the forward current - it's less at 1.25mA than if driven by 10mA, and so the internal switched voltage swing is further diminished, and may, or may not impact on the performance of the ENA input.

The bit of maths around Vossd is easily verified by yourself - measure the voltage, wrt ground, at the OSSD output when you have a fault condition. If the OSSD output was an ideal switch you'd expect it to be 0V. I expect it to be rather higher (calculated around 20V), based on the less-than-ideal switching behaviour of the opto-isolator (and if I have to correct my auto-correct for opto/onto once more....).

I'm cautious of playing too much behind a calculator - measure the voltage yourself. Reality beats theory any day. The one thing that worries me about my theory is that I would expect the behaviour to be accurately described in the owner's manual of the UB1. And the manual doesn't describe my perceived behaviour - so I could be wrong here.

I've tried to look online for a high-res image of the UB1 for information on the opto-isolator chosen - to no avail. If you can check and advise? It could be an intelligent selection of a device with an unusually high CTR. Pretty sure they are not buffered devices as they look to be 4-pin devices.


EDIT:

Here's an idea. Short the OSSD output to ground (or just the wire from the OSSD output). Either that will work as expected (inhibit each driver) or not. That's a quick way to fault-find the circuit.

[AndyUK]

Wow thanks for that Doddy, I see what you mean now :)

27317
What I think are the optoisolators (4pin IC directly above each output) have 838 written in small font above a larger central "P185". Bottom row is "GB JG".

Also, how the hell did that board get so dusty?

Measured the voltage but wrt 24V not ground (oops). Withe all drives on and connected, OSSD output off (i.e. fault condition drive should be disabled) I get 0V reading (so the OSSD pin is at 24V). With the OSSD output on (drives should enable) I get a reading of 23.3V (so OSSD pin is at 0.7V).

Connected a single drive to 5V and the OSSD pin without resistors, worked perfectly. Enabled and disabled the drive like a champ exactly as expected in both active low enable mode and active high enable mode (enabled in opposite situations obviously). Will try connecting all drives simultaneously next, and I guess worst case will just run them through a spare relay operated by the OSSD pin?

[Doddy]

Likely a TLP185 or equivalent. CTR = 100-400%. Your measured voltage is fine and indicates the behaviour should be as you expected. Disregard all my random ramblings about optos.

[Kitwn]

Likely a TLP185 or equivalent. CTR = 100-400%. Your measured voltage is fine and indicates the behaviour should be as you expected. Disregard all my random ramblings about optos.

As someone who likes to design and build the odd circuit of his own, I have found your 'ramblings' extremely informative.

[AndyUK]

I have found your 'ramblings' extremely informative.

Seconded, this train of thought has more than doubled my knowledge of Optos.

[Lee Roberts]

If I redraw your schematic (lesson #1, "Eagle" is not good for this)

Sorry to side track Andy...

Doddy have a look at Fusion 360, they've been working on updates for the PCB design side more recently, I don't know if schematic support is available as I haven't had time to explore just yet...Autodesk owning Eagle i'm now thinking probably not.

[Doddy]

Lee, the work auto desk have done is to integrate the eagle board design together with 3d models of components to post forward into F360 for correlation between electrical and mechanical design. Think of it as a 3D viewer for Eagle, but with obvious advantage for designing the mechanicals around the electrical design.

It’s neat when it works but a complete buggeration from a component library manager POV.

Unfortunately it doesn’t make schematic capture any better (though in fairness autodesk have developed Eagle more in the last couple of years than any of the previous owners)

Sorry!, Andy, thread hijack

[Doddy]

Lee, the work auto desk have done is to integrate the eagle board design together with 3d models of components to post forward into F360 for correlation between electrical and mechanical design. Think of it as a 3D viewer for Eagle, but with obvious advantage for designing the mechanicals around the electrical design.


Apologies, Lee - I think I understand where you was coming from. The latest update from AutoDesk for Fusion360 starts to integrate the functions, including schematic capture, from Eagle into the design editor. This is starting to make sense from the changes to the licensing introduced by AD recently - I'm guessing they're looking for convergence between F360 and Eagle - perhaps into a single product. Not sure I like this, and the integration at this time is a bit clumsy, but I'll hold my breath to see how this develops.

[AndyUK]

Y and X axis moving, apologies for the poor videography and mouth breathing; there are still no limit switches so I was trying to manually control and stay near the estop whilst filming, took far too much concentration.

The Y is substantially quieter (smaller single screw and better alignment I guess) and here its setup for 10m/min and 500mm/s^2.

The X still needs some alignment attention, here its running at 8m/min and 500mm/s^2. I think it was slightly crooked because at 10m/min something mechanical was slipping causing it to stall. Once a pulley was tightened and the gantry realigned it seems okay at 10m/min but time shall tell.

It's sounding and seeming okay to me, but I have very little experience to compare against, so comments and concerns appreciated.


https://youtu.be/e19MUBl4nDw

Here's a short clip of the slipping I was seeing, after tightening the pulley grubscrew but before realignment:


https://youtu.be/5qFjtBsfzp8

[JAZZCNC]

Hi Andy, Well done mate it's coming along nicely. Have you checked the steps per is correct because It doesn't look like it's traveling 8 or 10mtr/min to me, thou it's hard to tell from a video? Just use MDI and tell it to move a distance and check it moved the commanded distance. ie: G0 X100 it should move 100mm. Make sure you Zero the axis first and leave enough space to travel.

[AndyUK]

Thanks Dean :)

Interesting to know it doesn't look like 10m/min, I'll try measuring the speed. Haven't verified the steps per yet, I'm merely going off the theory. Steppers are 1.8° per step, 8x microstepping, 10mm pitch screw, set to 160 steps per unit, jogging at 100% (although granted I could be using the UCCNC software incorrectly!)

[JAZZCNC]

Thanks Dean :)

Interesting to know it doesn't look like 10m/min, I'll try measuring the speed. Haven't verified the steps per yet, I'm merely going off the theory. Steppers are 1.8° per step, 8x microstepping, 10mm pitch screw, set to 160 steps per unit, jogging at 100% (although granted I could be using the UCCNC software incorrectly!)

Well that's all correct going by the numbers(provided the MS are correct on drives) so could just be the video but quick measure will verify if it is or not.

[routercnc]

Great work well done !
For comparison my Y axis is sweet running like yours, and my dual screw X axis is much noisier. I think it’s because they are longer and there is much more going on.

The slipping in the second video sounds like classic stepper stalling to me. The stepper torque just falls away with speed so if the mechanicals are good then just drop the speed back.

Well done for getting this far it’s a great achievement !

[JAZZCNC]

For comparison my Y axis is sweet running like yours, and my dual screw X-axis is much noisier. I think it’s because they are longer and there is much more going on.

Yep happens on all machines over a certain length and it's a combo of vibrations through the frame and resonance from the screws. You should hear what a 10 x 5 sounds like in comparison. I'm currently just finishing one that's using rotating nuts and the X-axis still sounds much noiser than the Y-axis. I'll do a video when it's fit to be seen, it's still not fully dressed with wires and pipes hanging out everywhere.

[AndyUK]

The slipping in the second video sounds like classic stepper stalling to me. The stepper torque just falls away with speed so if the mechanicals are good then just drop the speed back.

Well done for getting this far it’s a great achievement !

Thanks :)

I haven't yet tuned the drivers to the steppers, and I've been a bit conservative with the current through them (the water cooling loop which feeds the spindle and the x motors isn't running yet) as I don't want to let them overheat inside the steel box section. Hopefully I'll be able to hit 10m/min reliably when that's done, otherwise I'll live with 7.5.

Today I got the spindle running and the Z axis moving, both seem okay for first use :) Had to swap the spindle rotation direction, and I'm not sure it's hitting the full speed (the VFD says 200 when the dial is at full range, but that might be because I changed the analogue input range for the UB1 which isn't yet in control). Now time to focus on getting those limit switches working before I smash into something!

Jazz, I also quickly verified the steps per using a pair of digital callipers, and the X axis was spot on at 10mm and 50mm. Y axis was 49.95 on a 50mm move which when considering I don't have ultimate faith in the measurement method I'm happy with for now :)

[AndyUK]

Also, having some fun finding an appropriate waste board. Being that its out in the unheated and uninsulated detached garage, I need something thats going to be stable.

I've been canvassing local shop fitters / plastics suppliers / kitchen fitters for some Tufnol 1P/13, Phenolic Sheet, or Trespa Athlon. Looking for approximately 20x800x1000mm - any quotes I get back are in the £300ish range which feels quite dear, is that expensive or about right? Does anyone have any recommended suppliers or alternative materials to look at?

[JAZZCNC]

Also, having some fun finding an appropriate waste board. Being that its out in the unheated and uninsulated detached garage, I need something thats going to be stable.

I've been canvassing local shop fitters / plastics suppliers / kitchen fitters for some Tufnol 1P/13, Phenolic Sheet, or Trespa Athlon. Looking for approximately 20x800x1000mm - any quotes I get back are in the £300ish range which feels quite dear, is that expensive or about right? Does anyone have any recommended suppliers or alternative materials to look at?

You should be able to get a piece of HDPE for a lot less than £300. I've just bought a 10' x 5' x 30mm and it was only £500.

[Dean jeffery]

I use these for HDPE and acetal

https://www.directplastics.co.uk/hdpe-sheet

[JAZZCNC]

I use these for HDPE and acetal

https://www.directplastics.co.uk/hdpe-sheet

Nar then stranger.!! . . . . Bit expensive that place. I'll find the name of the place I bought from and let you know. 3000 x 1500 x 30mm was less than half what they want and delivered.

[AndyUK]

And there was me thinking this chap had saved me some dosh!

[JAZZCNC]

And there was me thinking this chap had saved me some dosh!

Ah ah Dean is fairly local to me and they only deliver local so no point giving you their number down in the deep south. . .Lol

[Dean jeffery]

Nar then stranger.!! . . . . Bit expensive that place. I'll find the name of the place I bought from and let you know. 3000 x 1500 x 30mm was less than half what they want and delivered.

Hi Dean

Yeah it’s been a while [emoji106] don’t frequent on here often.

Yeah it’s not the cheapest of places but still cheaper than the OP [emoji23]

[Dean jeffery]

Ah ah Dean is fairly local to me and they only deliver local so no point giving you their number down in the deep south. . .Lol

Thanks anyways I don’t buy often or use a great deal when I do, just a few meter lengths.

Dean I’ve just given your email to a bloke at work, he’s been wanting a cnc router for a while.

He’s been asking me questions over the months and keeps sending me links to pre built low spec machines, so I’ve said just contact the bloke who built mine.

On a side note

Did some maintenance on mine last weekend, just a clean and re pack bearings and what not.

Also checked positioning and backlash

It’s not changed in over 3.5 years of use and it’s been used, I was shocked tbh

Back lash is under 0.01mm my DTI only measures in 0.01 increments but I’d guess at 0.005, and positional error well at 10m/min full travels it’s bang on the money [emoji106]

[JAZZCNC]

On a side note

Did some maintenance on mine last weekend, just a clean and re pack bearings and what not.

Also checked positioning and backlash

It’s not changed in over 3.5 years of use and it’s been used, I was shocked tbh

Back lash is under 0.01mm my DTI only measures in 0.01 increments but I’d guess at 0.005, and positional error well at 10m/min full travels it’s bang on the money [emoji106]

That's good to hear, always nice to get feedback like that.! . . You still cutting Carbon fibre and Ali parts for RC Cars.? Heath's lad (guy who deliverd machine with me) is racing Model touring cars and he's an expert crasher so might have some business for you. ..Lol

[Dean jeffery]

That's good to hear, always nice to get feedback like that.! . . You still cutting Carbon fibre and Ali parts for RC Cars.? Heath's lad (guy who deliverd machine with me) is racing Model touring cars and he's an expert crasher so might have some business for you. ..Lol

Credit mate it’s really holding up to tight tolerance all these years [emoji106]

Carbons the main material and the off plastic run not so much alloy now just makes far to much mess, and messes my spoil board up with using mist so only cut this for personal 1 offs that don’t require mist.

Been using some new cutting data and halved the previous machining time in carbon, been using this for around 18 months now.

Well if your mate needs anything just cad the parts up and the crashes will be cheap to fix [emoji106]

[AndyUK]

Regards limit switch end point placement, how close to the physical stop should I place the trigger point? Obviously want maximum travel, but don't want to slam into them at 10m/min.

[JAZZCNC]

Regards limit switch end point placement, how close to the physical stop should I place the trigger point? Obviously want maximum travel, but don't want to slam into them at 10m/min.

Machine dependant really because of different Gantry mass and inertia, do a little test hit the estop at a mark low down the travel and see how far it over travels. This will give some idea then just little more to be safe.

[AndyUK]

Had a weekend playing with the machine and finishing up a few bits.

27441 27442

I've used a 75mm cable tray to hold the 62.5mm wide X cable chain and fitted it with 3D printed supports. Looks great, and I think that cable tray size must be made for the cable chain, smoothly fits right in and glides in and out when going back and forth (gosh this post is starting to get a little suggestive...).

I've tidied up the wiring around the machine generally, although I still need to make a control box for all those switches!

All the limit / home switches are in place and working nicely, again 3D printed mounts. Thanks for the advice on placement Jazz.

I've got the coolant circuit filled and burped - the flow rate is absolutely tiny though, just a trickle, serves me right for running such a long loop with just the crappy little pump that turned up with the kit. Its 15m of loop in all due to the X axis stepper cooling, and 8mm piping, so I might need to upgrade the pump.

UCCNC is now controlling the spindle speed and direction which is great, and I'm using an old Xbox 360 controller to move the machine around which works great. However, I'm seeing the digital display on the VFD fluctuate and can hear the spindle isn't at a steady speed. This is an issue I've seen described with the analogue control methods with the UB1 and UCCNC, so I suspect I'll need to change over to a digital control signal in the future.

Regards spoil board, I plan to use trespa, but am using some cheap MDF to start with in an attempt to get some mistakes out of the way on something that really doesn't matter.




Roughly aligned the rails for parallelism
Checked the levelling with a precision straight edge - more details below.
Thrown the gantry on the rails - it glides super smooth (and made me very happy!)
After getting happy about that, I then got very sad. Turns out my steel frame is a bit of a rhombus! When I bring the gantry to one edge, it hits the end of one rail about 3-5mm before the end of the other, and the opposite occurs at the other end. I don' t think this will actually affect anything, except perhaps my pride...



Spent last night doing spot drilling on a waste board at all four corners and roughly measuring the squareness of the machine. I should have paid more attention to the above at the time - Its not that the steel frame is a rhombus. The X and Y axis are not quite 90 degrees, which leads to an error of 4mm across the two diagonals. I have a precision angle, but haven't got a way to nicely attach a dial gauge to the gantry yet - Its on my list though!

Initially I'd forgotten the above, and tried correcting by adjusting the home position switches, assuming the gantry was racking. I got the error to 1.5mm (thats 90.1 degrees) on the diagonal, and the next correction stalled the X axis, so clearly I was pushing the ballscrews out of alignment with one another and was twisting the gantry beyond it's limits. That was a big warning sign that I was doing something stupid; obviously the gantry should be nicely aligned to evenly wear the screws and not try to twist against the rails.

Now, I'm not too concerned. Ultimately this just means I've screwed up somewhere along the way getting the squaring on the gantry. Looking at the gantry carefully, I can see the gap between the side plates and the X carriages is slightly larger at the front than the back on one side, and the opposite on the other, which tallies with the rhombus I'm seeing. So I think the main problem is that the carriages are bolted onto the gantry slightly askew. My hope is that addressing this will solve my issue, and mean that without any screws attached my bearings will hit the same point on my rails and remove that earlier error I spotted.

Ultimately, worse case I'll need to remake the bearing plates which those carriages bolt onto (which I already planned to do anyway, I broke a drill bit in one of them so one carriage only has two bolts in - I was kinda hoping I could remake them with the machine itself...!).

I might however do a few cuts with this error in place, just because I'm at the stage where I can start to use the machine for it's purpose, and if I don't get some output soon I think I may get lynched by SWMBO....

[AndyUK]

The wife is happy! The CNC has produced something for her glass!

27465

Psstt... don't tell her that it would have probably been quicker on the table saw.....

Anyhow, very valuable day of learning. First cut was a V carve little sign. Very simple CAD and CAM in Vectric. Second cut was trying to get more serious making the above model, mostly to test the pathway through fusion. Unfortunately I didn't home the machine first, and the bastard had G28s hidden throughout... goodbye 4mm endmill and a few VFD fuses!! The item you see above is my 3rd ever cut with a little sanding. This is going to be a steep learning curve.....

[JAZZCNC]

TIP: Cut Air for the first few jobs until confident machine and Cam do as expected.!

[CNCRY]

The wife is happy! The CNC has produced something for her glass!

27465

Psstt... don't tell her that it would have probably been quicker on the table saw.....

Anyhow, very valuable day of learning. First cut was a V carve little sign. Very simple CAD and CAM in Vectric. Second cut was trying to get more serious making the above model, mostly to test the pathway through fusion. Unfortunately I didn't home the machine first, and the bastard had G28s hidden throughout... goodbye 4mm endmill and a few VFD fuses!! The item you see above is my 3rd ever cut with a little sanding. This is going to be a steep learning curve.....

Nice one Andy - good to see actual cutting and know it's possible to get there in the end! Although if its a steep learning curve for you it'll be a mountain for me:)

[Nickhofen]

Awesome work, I am glad to see you have finished with your machine.
Enjoy your cnc mate!

[CNCRY]

Interested how your machine is going Andy ? Managed to make anything in metal/ aluminium ? Photos :)

[AndyUK]

Machines going really well thanks - Haven't had an awful lot of time to dedicate to it recently (healthcare worker...) but having some fun when I do get the odd minute.

First thing was to add the temporary MDF bed, attach, level and surface it, along with tramming the spindle. Wish my spindle mount was a bit more conductive to that process, but hey ho, it works.

I've fitted my coolant mister with enhancements (thanks to Voicecoil) but haven't gotten around to any metals yet. All wood so far, got myself some birch ply for a project and have used it for a couple of other things too. I've got some composites on order which I'm looking forward to trying out too.

First thing was to make a quick and temporary control box - the random DIN rail with buttons hanging off was getting a little haphazard. Found an online CAD generator for the tabbed box of whatever size. I had to manually sharpen up those corners though, so it all got a bit rough! I tried using a compression bit, but hadn't got the first pass deep enough, hence the furry edges.

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Then I gained a new nephew - so clearly this needed more glass work and a frame. First try of 2-sided machining to create a pocket on the back for the glass plate to sit into.

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I'm currently working on a project that I'll probably make a thread about once I'm happy with it... but here is a sneak peak:

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Any guesses?

[Kitwn]

That's my kind of control box!
There are loads of designs for wooden joints that are designed not to have sharp corners so you can cut then on a CNC machine. Some nice examples at the link below. I've used the first, simple finger tenon design for some boxes.

I suspect you're building something inspired by David C Roy.

http://mkmra2.blogspot.com/2014/08/cnc-cut-wood-joinery.html

[Nickhofen]

I was ready to say that the project is one of those wheels for kids that they push them around the house and make a noise that drill your ears,but after that I think that this is not a wise man's choice to build something like that now that we stay home because of the pandemic! :smiley_simmons:
I am kidding,I do not know what it is.

[AndyUK]

That's my kind of control box!
There are loads of designs for wooden joints that are designed not to have sharp corners so you can cut then on a CNC machine. Some nice examples at the link below. I've used the first, simple finger tenon design for some boxes.

I suspect you're building something inspired by David C Roy.


Thanks Kitwn, really helpful link! :)

Yep - got it in one, I suspected anyone into their wooden clocks would know.

[CNCRY]

Good to see you are getting some time at least and some real life creations Andy! I think I need to use mine for every birthday/xmas present for the next 10 years to recoup the cost:)
What method did you use to tram the spindle?
Interested in the coolant mister too for the future - don't think I saw that in your build log?
Ryan

[Kitwn]

Thanks Kitwn, really helpful link! :)

Yep - got it in one, I suspected anyone into their wooden clocks would know.

I love some of the designs on that site, especially the ones that use the wood as a spring to snap pieces together. They do test the accuracy of your machine though, I copied one idea which made a joint that had the pieces fit rather like the pieces of a jigsaw. Except they didn't. That was the inspiration for the latest round of upgrades which I'm hoping will significantly improve the accuracy of my machine. The Z axis is now made of aluminium instead of plywood so I'm cautiously optimistic!

I consider wooden clocks to be a form of 'kinetic sculpture' just like Mr Roy's creations. Problem is I (unlike everyone else it seems) insist that a clock, any clock, should tell the right time. Hence my current (stalled for want of a working router) project for a GPS-locked wooden pendulum clock.

[AndyUK]

Good to see you are getting some time at least and some real life creations Andy! I think I need to use mine for every birthday/xmas present for the next 10 years to recoup the cost:)
What method did you use to tram the spindle?
Interested in the coolant mister too for the future - don't think I saw that in your build log?
Ryan

Haha - yeah. I've already gotten a couple of those ticked off...!

The mister is a £5 jobbie off ebay - nothing special to it, just the generic Chinese one you'll find. Voicecoil has made me a new nozzle for it to open up the flow - he discussed the modification in one of his threads; I'll post a picture when I next use it.

Spindle tramming - I used a dial gauge in the spindle, rotating it around on a surface place that is already setup to be planar to the Y and X axis. I have a tramming gauge which I would have preferred to use, but its with the mill locked down a few hundred miles up north.


I love some of the designs on that site, especially the ones that use the wood as a spring to snap pieces together. They do test the accuracy of your machine though, I copied one idea which made a joint that had the pieces fit rather like the pieces of a jigsaw. Except they didn't. That was the inspiration for the latest round of upgrades which I'm hoping will significantly improve the accuracy of my machine. The Z axis is now made of aluminium instead of plywood so I'm cautiously optimistic!

I consider wooden clocks to be a form of 'kinetic sculpture' just like Mr Roy's creations. Problem is I (unlike everyone else it seems) insist that a clock, any clock, should tell the right time. Hence my current (stalled for want of a working router) project for a GPS-locked wooden pendulum clock.

Haha - I set the router up for a 16mm diameter hole, along with a series of already prepared GCode files for +/- 0.1mm offsets to try and fit the first bearing in. I can't tell you how happy I was when the 0 offset file measured 16.00 on the digital calipers, and the bearing was a tight push fit first time. Bliss.

I suspect I'll end up trying to make a few of his designs... they're definitely in the amazing artwork category. GPS locking them however - that's another level!


Couple more projects - My Brother wanted a 'Plumshed' sign (don't ask - long story), so I did a V Carve with some google fonts. Really love how much the black paint adds.

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Also spent some time trying to improve my 3D CAD skills - mocked up a Sopwith Camel prop, and tried a 3D carve. The router did an amazing job (its about 600mm wide) - I really love how smooth and flowing the contour is after a single finishing pass with a 6mm ballnose. The only issue I had was that I messed up the CAM and only got half the model (oops). Before this cut I was slightly worried about if my Z axis was okay - one of the earlier 3D carves had some suspected lost steps - but it handled this one perfectly. Cooling is definitely a need-to-fix item on my agenda though - that little pump just can't cope with the length of cooling loop I've got, and after about an hour the lower section of the spindle was hot (still comfortable to touch, but I'm guessing it shouldn't build up heat if the cooling is working well).

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[Kitwn]

Nice work!
On the cooling front I found that larger diameter piping (8mm instead of 5mm I think) doubled the flow rate from the same pump. Short restrictions such as the inch-long pieces that connect to the spindle itself made no difference but it sure made a difference over the main several metres.

I built a prototype GPS clock last year, link below. The GPS receiver is the little blue circuit board that appears about 26 seconds in. The pendulum is oscillating freely at it's natural frequency, driven by an electromagnet, but is still forced to run in perfect sync with the one pulse per second (1PPS) signal from the receiver.

https://vimeo.com/343781598

[AndyUK]

I really like the joining of precise timing and electronics with wooden clock - fantastic!

Heres how the prop turned out, after a few duds and a bit more learning. Nothing special, but I'm rather pleased with my first two-sided 3D carve - quite hard to photograph that twisting shape though..

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Right - lets get back to building machines shall we? Its become rather apparent that dust collection is essential. I'm thinking I'll print one of Boyan's turbo shoes, but has anyone got any dust collection system recommendations? I'd like to be in the garage while its on, so thats a consideration.

[Kitwn]

Andy,
That prop looks great. I love the way the grain flows along the blades.

I do take a certain pleasure in the idea of a wooden pendulum clock being the most accurate timekeeper you can own. The mixing of technologies is fun, though some of the purist mechanical clock builders are not convinced.

[Nickhofen]

The grains that run the whole length of the propeller was the first thing I notice too, on purpose cutted from the piece of wood for more strength? Maybe a working propeller?
Andy did you hand sanded after the finish passes?
Is the propeller balanced? I mean did you try to spin it and see if it is?

[AndyUK]

The grain is deliberately running the length, yes. I did try a miniature one (10cm rather than 40cm) with the grain running in the opposite direction, but it snapped during the bottom side roughing.

I believe that's how real ones are supposed to be done for strength during use? But I have no intention of using this in anger - although it's quite tempting! This one is purely "because I can" and it was a challenge for my CAD, CAM and CNC experience!

Yes, hand sanded to remove tabs and clean up a bit, but the shaping is all through a 6mm ballnose. Obviously the photo is just a roughing cut - see the earlier post for what one side looks like after finishing pass. Prop isn't balanced perfectly - but does produce some wind! I should have machined the central shaft with the CNC but didn't want to risk the part at that stage as it's taken a few attempts - each requiring a few hours. It's not too far out though, I think a bit of selective sanding and it would be useable. I have a prop balancer somewhere; I'll stick it on later and see.

[Clive S]

I believe that's how real ones are supposed to be done for strength during use?

I think the real one's (Spitfire etc) are laminated not one piece . You have made a very good job of it :encouragement:

[Nickhofen]

I think spitfire had an aluminum alloy propeller, but yes the old blade of WWI was wood multilayer made.
You usually make two cuts on the wood to his length and then rotate the center beam 180 degrees at his longitudinal axe, for a small scale wooden propeller.
With your cnc you can always make an aluminum one.

[AndyUK]

Promised an update when I ventured into Aluminium; its only the smallest of steps, but I'm pleased with the results.

The "client" has requested a lampwork beadmaking tool which could form the molten glass into a heart shape. This is the first in a series of tests; the eventual product will need to have two identical sides to squish the bead into shape, but we've just started with a single side for now.

Tried two shapes, a 3D heart and a 2D heart. I pocketed and roughed with a 4mm single flute endmill at 18k RPM and 1.5m/min. Kept the DOC very low at 0.5mm as this is my first time, but the router wasn't phased in the slightest. Then finished with a 3mm Diameter ball nose, 24k RPM 1m/min. Very basic tool paths from aspire, nothing fancy. Went a bit overkill and gave it lots of air blasts to clear the ships and plenty of WD40 in between!

To give an idea of scale, these hearts are designed to fit within a 15mm diameter circle. Very small.

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My thoughts are slowly turning towards the 4th Axis that I'd like to add to this machine, but I haven't come across any dedicated build threads yet. Anyone got any initial recommendations / suggested reading?

[JAZZCNC]

Nice Job Andy, very rewarding isn't it when you get results like these. Don't be araid to push the machine, I'd be inclined to lower the step over on the ballnose so you get a smoother finish, it could be the pictures but it looks a little scolloped which comes from too large a step over. I use between 3 - 5% diameter on cutters 3mm or less and 10% on anything larger. Takes a little longer but get a nice smooth finish.

[AndyUK]

Thanks Dean - I used Aspire's default step over, so no idea what it was set to! I'll look into it tonight and get it into that range.

Out of interest, what would you expect to see DOC wise on a router like this with a 4mm single flute? APT suggests slowing down from those parameters once you're over 1.5 D, but I assume that advice is really for mills; 6mm felt like quite a big chunk to be taking.

[JAZZCNC]

Thanks Dean - I used Aspire's default step over, so no idea what it was set to! I'll look into it tonight and get it into that range.

Out of interest, what would you expect to see DOC wise on a router like this with a 4mm single flute? APT suggests slowing down from those parameters once you're over 1.5 D, but I assume that advice is really for mills; 6mm felt like quite a big chunk to be taking.

Ye aspire is mostly based on wood which is a little less forgiving so any small scollops can be sanded away but in Ali you want a smaller stepover for the best finish.

Difficult to say because every machine is different, spindle power and rigidity plays a big part. If it was me I'd start at 50% D and feel your way down. Or just go for it turn the spindle up to full RPM so you are getting Max torque then go with 1.5xD and play with feeds n speeds.

[AndyUK]

If the 4th axis is for marking round parts like a rolling pin etc. I have done it on my laser engraver by using a small stepper and connect it to the Y axis, intead of the gantry moving the length it stays still but the rolling pin turns as the laser writes, not sure which axis is which on a cnc router so it might be X in your case. Its a simple device with a 3d printed mandril one end that grips and a pinpoint on the other and the work is held in between, I'd upload a photo but i gave it to a friend. Its not a full permanent 4th axis but you can write on round tubular objects, on a router probably cut them too. Not sure if its what you need, just a thought.

Derek
PD Are you the same Andyuk that designed the belt tensioner for the eleksmaker A3 pro laser engraver, every time I see a post of yours it reminds me of it as the way you write AndyUK is the same.

Hi Derek,

Sorry, not the same, just another Andy from the UK ;)

Yes I've seen that type of 4th axis, quite ingenious! I worry about the accuracy of such a system though, and I wonder if the Cam is a nightmare! I was more thinking along the lines of a high torque stepper, some gear reduction, a chuck and a tailstock.

Thanks for that Jazz - much appreciated.

[Muzzer]

Not sure if it's quite what you are after but I've just about finished a fairly conventional 4th axis using one of the harmonic drives and a servo motor, all culled from one of the Korean scrapyards. Looks good so far - had it jogging yesterday.

This is for a metalworking milling machine, so has a 125mm 3 jaw chuck which I have bored through 36mm, so I can hold long stock.

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https://www.youtube.com/watch?v=CprMqxnXcEE

[AndyUK]

I like! Thanks Muzzer :)

[AndyUK]

Quick update to the Aluminium Bead Presses. Other half demanded six sizes of the 3D hearts in both a horizontal and vertical press. Settled on a 0.2mm step-over - we did some tests lower down but whilst the finish was buttery smooth the tooling marks arn't translating into the glass, so decided this was a good compromise (or if they are, they're soon rounded up by heat). Getting some great consistency out of the presses, so happy customer :)

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We're now exploring other shapes.... (The ribs are intentional - not poor machining!)

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The machine is doing fantastically. Its been running 9 months now and hasn't skipped a beat. I had my first acrylic cutting experience recently which went very well. We used two layers to create an illuminated panel, solid grey on top cutting down through to a transparent opal - and if it wasn't a sign for my own address I'd be sharing pictures!

My 4th Axis dreams are on hold for the time being however - a Warco metalworking lathe has just arrived in the garage, which changes things slightly, and I now need to learn how to turn. Never a quiet moment!

[fer662]

This build is looking great! I've been following for a while since I want to rebuild my table to be pretty darn close to this one, only 1.5x1. I like the fact that you used an hybrid solution for assembling the table. My workshop is in the first floor so if i had to ever move and it was all soldered it'd be a death sentence. Is there any chance you would upload the solidwords stuff? Thanks a lot!

[AndyUK]

This build is looking great! I've been following for a while since I want to rebuild my table to be pretty darn close to this one, only 1.5x1. I like the fact that you used an hybrid solution for assembling the table. My workshop is in the first floor so if i had to ever move and it was all soldered it'd be a death sentence. Is there any chance you would upload the solidwords stuff? Thanks a lot!

Hi fer662,

Thanks :) Although my table is welded, and won't be coming apart without a grinder! The bolts were used to position everything for my first time welding, and are mostly aesthetic now. If I did need to separate the frame I'd need to repeat the epoxy levelling - its something I've mulled over, as we're considering building an extension which might trap the CNC in the workshop for good...

Happy to send over any pictures of the model you'd fancy and provide dimensions, but the CAD is such a sprawling mess its a nightmare to get everything together to share. I'm also not sure of the benefits - if you're serious about building, designing the CAD model yourself is very helpful in organizing your thoughts, and helps your understanding how it all fits together, and it needs to be specific to your components. There are also a number of improvements I'd make now I've gone through the process, so if you start a build log you'll get a lot of suggestions from all directions.

[fer662]

Hi fer662,

Thanks :) Although my table is welded, and won't be coming apart without a grinder! The bolts were used to position everything for my first time welding, and are mostly aesthetic now. If I did need to separate the frame I'd need to repeat the epoxy levelling - its something I've mulled over, as we're considering building an extension which might trap the CNC in the workshop for good...

Happy to send over any pictures of the model you'd fancy and provide dimensions, but the CAD is such a sprawling mess its a nightmare to get everything together to share. I'm also not sure of the benefits - if you're serious about building, designing the CAD model yourself is very helpful in organizing your thoughts, and helps your understanding how it all fits together, and it needs to be specific to your components. There are also a number of improvements I'd make now I've gone through the process, so if you start a build log you'll get a lot of suggestions from all directions.

Oh, for sure I would be making my own CAD, but since your design is pretty similar to what i had in mind i'm bound to stumble upon the same problems and decisions and thought having a tried and tested design would help me resolve those at some point. The most significant difference is I don't have access to a mill... I do have my current tabletop CNC that i intend to use to machine the aluminum flatbar into whatever plates I need, and I also have a hobby lathe (not the crappiest kind, I think its the same as the Warco you might be more familiar with in the UK).

Oh, so you essentially welded the sides, then assembled the table with screws and taps, and then welded it together? was it mostly to prevent it from moving?
What about the legs, did you solder anything below the open 80x80 tubes? I cannot bolt the table down to the floor because i have floor hitting and i'm sure i'll be unlucky enough to hit a hose with the drill. Probably won't be necessary as the table will weight a shit ton.

Sorry my reply is a mess! Yes, i'd appreciate any pictures you could send about how all the frame is attached.

Attaching a pic of my baby. I started this years when I didn't even have a workshop, let alone a proper one. It literally spent some time in the coffee table in the living room until i stole the laundry room from the wife. Now that i do and i've had time to see the flaws it's time for an upgrade. I already have all the hiwin style rails and longer screws. I'll be reusing only the longest axis rails that are now in X for the Y gantry (1m). I've already redone the control box and electronics and added the extra driver for dual X screws.

[AndyUK]

Ok sounds good - let me see what I can do about the CAD model to help you out.



Oh, so you essentially welded the sides, then assembled the table with screws and taps, and then welded it together? was it mostly to prevent it from moving?
What about the legs, did you solder anything below the open 80x80 tubes? I cannot bolt the table down to the floor because i have floor hitting and i'm sure i'll be unlucky enough to hit a hose with the drill. Probably won't be necessary as the table will weight a shit ton.


Looking back over the photos in my thread, I can see why you thought it was just bolted. As it was my first time welding, I wasn't at all happy with how the process was going - I thought the welds were coming out pretty ugly and I had a number of "retries" grinding out bits that felt crappy and weak and doing them over again. As a result, I just didn't take many photos of the build during this stage, I was quite disheartened with it. It wasn't until I had something I was happy with (after lots of grinding, welding, regrinding, smoothing with some filler, sanding, then finally painting that I started taking photos of the frame again.

Lets start back here - October 2018, all the frame steels (bar one!) were cleaned up, tapped, bolted together into an assembly I was happy with.

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I then turned the frame over, and started welding the caps on the bottom of the square tubing for the feet. I'd drilled and tapped these prior - but in hindsight I'd have welded a nut on the inside first to give more thickness to the thread. It was at this point I set my crotch on fire. ;)

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By the end of the day I was quite happy with how it was sitting on its new feet. I'd also started preparing the steels for the adjustable height bed.

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Then I started to tack weld the joints together all the way around, being sure to do one tack, then move around the machine to try and reduce distortion. Once that was done, I came back to each one in turn and gave it a full bead. Rinse and repeat.

I was so unhappy with it I literally don't have a picture of the frame until it was painted.... and even then I wasn't happy with the brush marks in the first coat, so that took a while to sort out!

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[Kitwn]

Andy,
That's a very informative and encouraging set of photographs. And a dire warning re starting fires in awkward places! I'll be reassembling my own machine in it's new home before long and a new welded base is going to be a major upgrade.

If I can produce something that looks that good (even with brush marks in the paint) I'll be well pleased.

Kit

[AndyUK]

If I can produce something that looks that good (even with brush marks in the paint) I'll be well pleased.

Thing is, now I'm using it, I've scratched and chipped the paintwork a number of times. I think I've given up trying to be precious! Still functional after all.... ;)

[JAZZCNC]

Thing is, now I'm using it, I've scratched and chipped the paintwork a number of times. I think I've given up trying to be precious! Still functional after all.... ;)

With the machines I build looks plays a small part, mostly to help with the appeal to new users who tend to buy on looks rather than functionality. then I can educate them on what's required for good machine.
On my own personal machines I have absolutely zero interest on how they look, infact, they look SOOOOO bad with wires and crap hanging off them from product testing or failed tests or just plain lazyness regards cleaning, (No lets be honest I've never cleaned it, occasional blow job if it;s lucky.:whistle:) I wouldn't dream of ever showing them to anyone because if I did no one would ever buy a machine off me again...:hysterical:

[fer662]

Ok sounds good - let me see what I can do about the CAD model to help you out.



Looking back over the photos in my thread, I can see why you thought it was just bolted. As it was my first time welding, I wasn't at all happy with how the process was going - I thought the welds were coming out pretty ugly and I had a number of "retries" grinding out bits that felt crappy and weak and doing them over again. As a result, I just didn't take many photos of the build during this stage, I was quite disheartened with it. It wasn't until I had something I was happy with (after lots of grinding, welding, regrinding, smoothing with some filler, sanding, then finally painting that I started taking photos of the frame again.

Lets start back here - October 2018, all the frame steels (bar one!) were cleaned up, tapped, bolted together into an assembly I was happy with.

29093

I then turned the frame over, and started welding the caps on the bottom of the square tubing for the feet. I'd drilled and tapped these prior - but in hindsight I'd have welded a nut on the inside first to give more thickness to the thread. It was at this point I set my crotch on fire. ;)

29096 29094 29095 29097 29098 29099 29100

By the end of the day I was quite happy with how it was sitting on its new feet. I'd also started preparing the steels for the adjustable height bed.

29101

Then I started to tack weld the joints together all the way around, being sure to do one tack, then move around the machine to try and reduce distortion. Once that was done, I came back to each one in turn and gave it a full bead. Rinse and repeat.

I was so unhappy with it I literally don't have a picture of the frame until it was painted.... and even then I wasn't happy with the brush marks in the first coat, so that took a while to sort out!

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These are going to be really useful. I appreciated it! I'll post my table on my own thread whenever I have time to start it.

[Neale]

One of the most interesting things to do is have a look round someone else's workshop. One of the most embarrassing things is to show someone round your own...

As for paint - wossat? They don't have to look pretty to do a useful job.

[AndyUK]

Notice how the garage started off relatively empty, but quickly gets fuller and messier throughout the photos? Its only gotten worse.....

[fer662]

I've been hard at work with the CAD! Could I bother you for some measurements? Could you tell me how far apart you have the linear bearings for the same rail on each of the axis... Say.. Measuring from the outside of the blocks? (and if you're happy with the resulting rigidity)? It's the one area where I don't want to simply overdo it since you lose work area.

[Kitwn]

With the machines I build looks plays a small part, mostly to help with the appeal to new users who tend to buy on looks rather than functionality. then I can educate them on what's required for good machine.
On my own personal machines I have absolutely zero interest on how they look, infact, they look SOOOOO bad with wires and crap hanging off them from product testing or failed tests or just plain lazyness regards cleaning, (No lets be honest I've never cleaned it, occasional blow job if it;s lucky.:whistle:) I wouldn't dream of ever showing them to anyone because if I did no one would ever buy a machine off me again...:hysterical:

It's interesting to see how much effort different people put into making the parts of their machines look good. There's even one in the archive with beautiful red anodised parts that I would have just filed the sharp edges off and left at that.

For a professionally made product there is always the element of customer confidence. If the surface finish is poor how much care and attention did the manufacturer take over the bits that DO matter?

[fer662]

It's interesting to see how much effort different people put into making the parts of their machines look good. There's even one in the archive with beautiful red anodised parts that I would have just filed the sharp edges off and left at that.

For a professionally made product there is always the element of customer confidence. If the surface finish is poor how much care and attention did the manufacturer take over the bits that DO matter?

I mean... Most of us end up spending way more than it'd have cost to just buy the machine done... It's a matter of pride in what you build at some point, and for some people aesthetics is a part of that.

[Kitwn]

I mean... Most of us end up spending way more than it'd have cost to just buy the machine done... It's a matter of pride in what you build at some point, and for some people aesthetics is a part of that.

I agree completely, some machines are a work of art in themselves.

[Neale]

Ah, that's the problem with my machine! I never was very good at art. I only show my router to visitors wearing blindfolds, and who promise not to laugh...

[AndyUK]

I've been hard at work with the CAD! Could I bother you for some measurements? Could you tell me how far apart you have the linear bearings for the same rail on each of the axis... Say.. Measuring from the outside of the blocks? (and if you're happy with the resulting rigidity)? It's the one area where I don't want to simply overdo it since you lose work area.

X-Axis (dual, longest dimension, probably should be referred to as Y but I've long ago given up with that), ~280mm between the near edge of the first carriage to the far edge of the second (i.e the maximum possible dimension!). That was designed so that the spindle fell between the two.

Y-Axis (along the gantry) ~ 170mm. This mostly came out of wanting a 15cm wide Z axis plate and then having 1cm side plates.

Z-Axis ~205mm. This coincides with the height of the aluminium gantry profile, and the Y rails and carriages. The bottom one is placed as low as it can be without blocking the bolts on the lower Y carriage assembly plate, the top one is placed as far up before fouling the bolts on the upper one.

Totally appreciate the work area concern. Its one of the things that slightly frustrates me with this design is the work area is substantially smaller than the footprint - but hey. I'd recommend extending the rails at one (or both) ends if you can - If you extend rearward you can cut on the entirety of the bed, a slight forward extension would allow vertical clamping and working.

[Kitwn]

Ah, that's the problem with my machine! I never was very good at art. I only show my router to visitors wearing blindfolds, and who promise not to laugh...

I can appreciate that. It was only shortly before I had to disassemble my machine for moving house that I finally replaced the plywood 'mock-up' Z axis with a real aluminium version. But then I always have been a fan of Heath Robinson.

[AndyUK]

Christmas Gift:

(Plans from)
https://wilkerdos.com/product/rocker-templates/

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[Nickhofen]

Nice!

[Kitwn]

Christmas Gift:

(Plans from)
https://wilkerdos.com/product/rocker-templates/

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That's wonderful, my sister would love one of those! I wonder what it would cost to send the parts from Tasmania to Walkden in time for her birthday? She'll be 70 next year.

[Tom J]

Had a weekend playing with the machine and finishing up a few bits.

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Like the idea of hiding steppers inside box. I designing similar machine and will pour granite into top frame and use heavy duty dampers between top frame and stand.

[AndyUK]

Like the idea of hiding steppers inside box. I designing similar machine and will pour granite into top frame and use heavy duty dampers between top frame and stand.

It seems to have worked well for me, but I did have concerns about the temperatures, so they're on the same watercooling loop as the spindle using some aluminium blocks wedged tightly up against them and a bit of thermal paste.

[CNCMEBABY]

Hi Andy,

I'm converting an X3 mill to CNC and after reading your build log amongst others I've been 'borrowing' heavily from your router electronics and circuit design. Could you tell me what software you used to create your circuit diagram please? Also, I saw your capacitor holders and noted that you printed yours after buying the wrong ones - inspired me to get a 3d printer, they were my first job. Just made protective caps for the top too.

I'll put photos of the bits I've made for the mill over on my build log when I've got a little further.

many thanks and stay safe

Geoff

[AndyUK]

Hi Geoff,

Pleased the build log is helping :)

I used MS Visio 2016 to create the diagram - I tried a wide range of CAD and electronic design softwares, but in the end Visio was just easier to use and create a colour coded diagram that made sense in my head. It took a long time to get it all down, but really helped organise my thoughts and work out a load of problems on paper first. I've attached the Visio file if you want to see how its done.

Yeah the cap holders were a bit of a "d'oh!" moment - the 3D printer did a great job with those and a number of other little bits around the machine towards the end - I love the cable tidies and the proximty sensor mounts. Unfortunately with house rennovations the poor thing is currently sitting under a mountain of dust.... The cap lids sound like a great idea though - far tidyer than my hot-glue blobs!

Looking forward to seeing your progress photos! :)

Andy

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[AndyUK]

Finally got around to trying my first inlay with this machine. Tried to challenge it by using a series of line widths, 0.5mm up to 3mm. Classic walnut and maple. 70x70mm square.

Used a 30 degree V bit, 2mm inlay depth, 1mm glue void depth, 1mm air gap above.

Plug and base (are there real names for these?) - Ran the cut twice on each to clear up some fuzzy bits - suspect my feeds and speeds arn't quite right, but I was being conservative.
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Glue time.... used some pretty standard PVA, that might come back to bite me but seems to be working.
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Trimmed the excess slowly and gently... reveal time!
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Some sanding through the grits, add oil... et voilà.
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Not perfect; looks like theres some reaction going on at the interface between the two woods, and I think there was an imperfection in the maple or the plug cutting that caused that slight discontinuity, but overall quite pleased for a first attempt.

[JAZZCNC]

Looks good Andy, nice feeling isn't it when you see the fruits of your labour produce stuff like this. Well done..:toot:

[Kitwn]

If my first effort (on the ToDo list behind a few more urgent tasks) looks that good I shall be happy. What's next?

Kit

[AndyUK]

What's next?

Well... I once said this about my wooden control box:



First thing was to make a quick and temporary control box...
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Turned out temporary is over a year! I've also got a much better idea about the buttons I wanted, so popped a few more on there.

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Also coming up with a few ideas for design modifications. I'm considering adopting the two plates idea on the X axis to make the gantry adjustment more independent from the ballscrew and linear rails. It will also add a little height to the gantry; I'm finding that although the bed height is adjustable in theory, the work involved is quite prohibitive (its bloody heavy, you need to re-level everything, and then you're working at a non-optimal height). I've found that with tool length, my current setup can only manage a depth of about 50mm or so. With a small bed height adjustment and a few tweeks I should be able to get a bit more room. Then theres the lack of a tramming plate on the Z axis, and it would be nice to have my Z probe plate wired so that it travels around with the spindle and is always close to hand....

[Kitwn]

Also coming up with a few ideas for design modifications. I'm considering adopting the two plates idea on the X axis to make the gantry adjustment more independent from the ballscrew and linear rails. It will also add a little height to the gantry; I'm finding that although the bed height is adjustable in theory, the work involved is quite prohibitive (its bloody heavy, you need to re-level everything, and then you're working at a non-optimal height). I've found that with tool length, my current setup can only manage a depth of about 50mm or so. With a small bed height adjustment and a few tweeks I should be able to get a bit more room. Then theres the lack of a tramming plate on the Z axis, and it would be nice to have my Z probe plate wired so that it travels around with the spindle and is always close to hand....

Very interesting. Your wooden control box is much neater than my re-purposed PC case will ever be!

I used two back plates for the gantry-mounted axis (Y on my machine) mainly out of practicality. It means that I can have the fixing screws for the linear bearings for the Y and Z axis overlapping, gave greater rigidity as I could only get 12mm plate and meant that I had some wiggle room to get the two axes exactly perpendicular after marking out bearing and rail mounting holes by hand and drilling them with an ordinary drill press. It also allows the whole Z axis assembly to be removed as a unit if required.

The real trick is working out an accurate way to measure whether the two axes ( ie the rails) are really perpendicular or not that is separate from measurements of where the axis of the spindle is pointing. I haven't quite cracked that one yet. I know the axis of the spindle is accurately perpendicular to the Y axis but I have no way of knowing if the spindle itself and the Z axis movement are precisely parallel.

Kit

[ZASto]

If your axes are not perpendicular to each other you will have a parallelogram on your extreme points.
Put a sharp tipped engraving bit (or sharp nail :)) in your collet and mark 4 dots on your table (use masking tape) at coordinates: 0,0; 0,MaxX; MaxY,MaxX and 0,MaxX, then measure DIAGONALS!!
If there is a difference, you are out of squareness.

[MikeyC38]

Hi Kit
On my build I wish I had given more thought to tramming adjustment as I now have to use metal shims to get everything right. Some sort of screw adjustment with a wedge may work. For tramming I could'nt get on with a single dial meter so bought this (https://www.machine-dro.co.uk/edge-technology-pro-tram-system-with-1-2-inch-shank) and I found it to be money well spent

Kind Regards
Michael

[Kitwn]

If your axes are not perpendicular to each other you will have a parallelogram on your extreme points.
Put a sharp tipped engraving bit (or sharp nail :)) in your collet and mark 4 dots on your table (use masking tape) at coordinates: 0,0; 0,MaxX; MaxY,MaxX and 0,MaxX, then measure DIAGONALS!!
If there is a difference, you are out of squareness.

Thanks for that, but you are referring to aligning the X and Y axes. I think Andy was talking about the construction of his Z axis assembly. If not then my last post was a complete pile of crap!

[Kitwn]

Hi Kit
On my build I wish I had given more thought to tramming adjustment as I now have to use metal shims to get everything right. Some sort of screw adjustment with a wedge may work. For tramming I could'nt get on with a single dial meter so bought this (https://www.machine-dro.co.uk/edge-technology-pro-tram-system-with-1-2-inch-shank) and I found it to be money well spent

Kind Regards
Michael

My machine is covered in shims! At least I built it in a way that makes it possible to access the places I need them easily enough.

I've seen the tool you linked to before but used a different method myself which was much less costly and used the Z axis DRO as a micrometer. This uses taught wires stretched between the long axis rails (X on my machine) to create the reference plane for aligning the gantry. This seems the best way to do it if your machine design allows it since these rails (once proven parallel) ARE the plane to which the other axes have to be parallel or perpendicular. Once that's all aligned then skimming the bed brings it into same plane and is the final job to be done. I wrote a thread about it last year and there's some updated stuff on my build log after I moved house and did it all again.

http://www.mycncuk.com/threads/13627-Tramming-With-Taut-Wires

Kit

[AndyUK]

Thought it might be interesting for others designing their control boxes to see why I've made my new one like this and how it works. Also welcome to hear any improvement suggestions.

My typical workflow is:


Turn on the CNC & PC (UCCNC Autoboots)
Reset the EStops (Red momentary reset button lights when safety circuit is tripped) & Turn on the wireless (bluetooth) Xbox controller.
Enable the motor drivers on the control box (Purple latch button - lights when motors enabled).
By this time UCCNC has loaded, so use the Xbox controller to do a software reset on UCCNC (the start key).
Home the CNC. This can be done by pressing the (white) Zero button on the control box. This button homes if the CNC isn't homed yet, otherwise it resets the X&Y position to zero if its lit up. The button only lights up when the CNC is idle (i.e. stationary not running a cycle or dwell), homed, and the spindle is off.
Load the GCode using mouse & keyboard.
Setup the work piece & do a tool change.
Set the X&Y zero coordinates, positioning with the Xbox controller, then press the Zero button on the control box again.
Set the Z zero coordinates using the touch plate by pressing the Probe button (Orange latch button - lights when a probing routine is running or soft probing mode is enabled) which runs the auto-tool height setting macro.
Limits & work holding checks.... If I do somehow hit a physical limit (only really posibile at startup due to softlimits) the yellow LED illuminates to indicate an inductive limit switch is triggered. Pressing the latch button allows limits override until the switch is released, at which point the LED turns off. Softlimits can also be toggled at any point with this switch.
Engage water pump if needed.... (Blue latch staight to relay in control cab)
Press the cycle start button in to start the cut. The cycle start button is a green latching button that lights when a cycle is running.
If needed, releasing the cycle start button will feedhold.
Engage mist if needed.... (Blue latch staight to relay in control cab)


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I've recently updated to Windows 10 just so I can have this wireless bluetooth controller. Expensive? Yes.. Awesome? Totally. I'm using Crafty CNC's Plugin (http://www.craftycnc.com/plugins-for-uccnc/) to give extended functionality, I tried it a year back and wasn't too impressed, but after trying again and ironing out a few bugs I'm really happy with it now.

The left analogue stick gives up and down control over the Z axis, varying in speed cubicly between 0-50%. Holding down the left trigger at the same time changes this to 0-100%. This means you can quickly get to the right position, but have very fine positioning control as well. The right analogue stick and trigger do the same for the X and Y axis. I've set the ABXY buttons to also jog X and Y with feedrates controlled by the left and right bumpers, this is really helpful for large innaccurate rapids across the table, or if you want to be sure to constrain motion to just one axis.

The "Start" button on the controller is set to toggle the software reset on UCCNC. This is good to get things started, and is effectively an E-Stop button for the controller. The "Menu" button is set to toggle feed hold as a mobile pause button.

This leaves the 4 Dpad buttons free for assigning to other functions I haven't quite decided upon yet... :)

I've also got a docking station to keep the controller charged up and give it a nice safe "home"! - Oh and you see that single board PC sitting on my subwoofer? Thats what I run UCCNC on. Its a quad core i5 @ 2Ghz per core, 8GB ram, 256GB SSD and with some serious integrated graphics.


https://youtu.be/MLwGqcwMeeo

[Nickhofen]

Awesome,thanks for sharing!

[Kitwn]

Nice setup Andy. At the other end of the Xbox budget range I'm using the plugin built into UCCNC and a dirt cheap USB Nintendo style controller which works OK for jogging and Z zero setting but going wireless would be very helpful. Understanding how to use the probing control is on my ToDo list.

The only thing you might add would be a hard-wired interlock switch for the spindle when doing manual tool changes. I have one which interrupts the start wire from the controller so that no accidental button press or software glitch can spoil my Jimmy Page impersonations.

[AndyUK]

Understanding how to use the probing control is on my ToDo list.

Z-Axis probing is a complete game changer, I really don't know how I went without that initially. So simple to setup as well; just have a 0V clip on to the tool (I've cheated and run a dirty 0V line to the spindle holder), and a second "Probe" line from the UB1 to a block of aluminium. Setup one line in UCCNC, and you can use JSP (jog safe probing) immediately which is great for X&Y. Measure the block thickness and quickly google a tool height setting macro, and within 10mins you'll have perfect and automated Z height setting. I'm now looking into having a permenant block in one corner and letting it have a bit more automation on those tool changes, but one step at a time.



The only thing you might add would be a hard-wired interlock switch for the spindle when doing manual tool changes. I have one which interrupts the start wire from the controller so that no accidental button press or software glitch can spoil my Jimmy Page impersonations.

Thats a great idea - I've shyed away from anything contactor/relay like on the power side of the VFD, but theres nothing to stop me putting a relay on the control logic side that would drop it into a safe state. Still not completely foolproof because short of powering down the VFD at every tool change theres always some risk the high quality chinesium in the VFD will go haywire....

[Kitwn]

Z-Axis probing is a complete game changer, I really don't know how I went without that initially. So simple to setup as well; just have a 0V clip on to the tool (I've cheated and run a dirty 0V line to the spindle holder), and a second "Probe" line from the UB1 to a block of aluminium. Setup one line in UCCNC, and you can use JSP (jog safe probing) immediately which is great for X&Y. Measure the block thickness and quickly google a tool height setting macro, and within 10mins you'll have perfect and automated Z height setting. I'm now looking into having a permenant block in one corner and letting it have a bit more automation on those tool changes, but one step at a time.



Thats a great idea - I've shyed away from anything contactor/relay like on the power side of the VFD, but theres nothing to stop me putting a relay on the control logic side that would drop it into a safe state. Still not completely foolproof because short of powering down the VFD at every tool change theres always some risk the high quality chinesium in the VFD will go haywire....

Thanks Andy, I will read up on the UCCNC probing.
I take your point about the chinesuim (lovely word by the way. I'm rather proud of having invented the word 'polycrapoline' to describe the cracked-within-weeks material used in some HV breakers I had the misfortune to work on many years back). It's for each of us to decide the level of risk we are willing to accept in our home workshop.

I was once very shocked to find an interlock system in a former employer's premises which, when made 'safe' left an HV power distribution transformer able to be back-fed if a microscopic transistor inside a PLC microchip went short circuit and decided to power an external relay which would close an HV breaker which was NOT included in the electromechanical interlocking. The risk I'm taking in not powering down the VFD every tool change is similar but the consequences, though potentially serious, are not guaranteed fatal and I only touch the sharp tool itself for a few seconds.

[AndyUK]

I've recieved a question about my UCCNC setup, so thought I'd share and discuss my config in public, just incase it helps a future builder.

The vast majority of these settings are taken directly from the UB1 manual, where there is a section on UCCNC and Mach3 setups. All the port and pin settings are taken from the UB1 manual, in combination with my circuit diagram.

Axis Settings (X/Y/Z/A)
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Note slaving of X and A. X&Y Steps per is pretty self explanatory (200 steps per rotation on the steppers, 10mm pitch screws, 8x microstepping = 160 steps per mm). Z is 5mm pitch so 320mm. Y&Z use a travelling inductive limit so port and pins identical. X&A have independent static switches for home and -ve limit, but share a +ve limit switch. Speeds and accelerations are set quite conservatively to avoid stalls.

Spindle Settings
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As per manual, nothing special here.

General Settings
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Mostly as per UB1 manual, but note use of soft limits, ignore unknown gcode (bit risky), M6 pauses for manual tool changes, & homing sequence.

Input Settings
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As per manual, nothing special here.

Input Triggers
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These handle my control box switch inputs, you can make the same switch have multiple actions, some occur on depress and some on release (hence the low tick). If you see high numbers in the function code its a custom macro to do more complex actions, like my Z height probing or my Zero button which does homing or X&Y zeroing depending on the machine state.

Output Triggers
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These exclusively control LEDs on my control panel, alongside some of my macroloops.

Xbox Controller Settings
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See my previous post to discuss these.

[AndyUK]

Robertspark's UCCNC Macros, Screenset and MODBUS manual is also a very helpful reference. See attached. Not only does it highlight all the inbuilt macro functions, but also has tables at the end listing the inbuilt function codes and LED codes.

[AndyUK]

I take your point about the chinesuim (lovely word by the way. I'm rather proud of having invented the word 'polycrapoline' to describe the cracked-within-weeks material used in some HV breakers I had the misfortune to work on many years back).

Chinesium is one of many AvEisms - search AvE on youtube, you're in for a treat. I suggest starting with some of the BOLTR (Bored of lame tool reviews) which are extremely informative teardowns and tests of various powertools. He is a bit of an interesting character, but well worth watching. And of course ThisOldTony needs a mention - especially his CNC build videos.


It's for each of us to decide the level of risk we are willing to accept in our home workshop.

I totally agree, and please don't take my words as any endorsement or critique; merely just my rambling commentary on which failure modes I think your suggestion protects from and those it doesn't.

[Kitwn]

Had a quick look at AvE. One to listen to while I'm doing something else. I watched a few ThisOldTony videos ages ago and had forgotten about him. I hope he doesn't read this and take it personally! My favourite YouTuber is Sped Spedding. I don't think he knows anything about CNC but he sure can play a guitar like ringin' a bell!

Kit

[AndyUK]

My wife and I had our first child over the summer, so haven't had an awful lot of time in the garage....! But I have managed to apply the inlay technique to build a set of toy blocks for her to play with. The faces you can't see spell out her name, and my wife picked out a number of shapes that mean things to us - there's at least two of everything so she can play match the shape too!

Hope everyone is doing well,
Andy

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[CharlieRam]

They look really good [emoji122]

Sent from my M2003J15SC using Tapatalk

[JAZZCNC]

Congrats on the baby and those cubes look excellent...:triumphant::toot::thumsup:

[Nickhofen]

Awesome inlay work,I hope to use that technique on my guitar building projects.
Congratulations for the new family member!!!

[Kitwn]

Love the blocks! You can never start too early in developing a mature, discriminating aesthetic sense in the young.

[fer662]

Andy Welcome to the forum and a merry Xmas.

You have certainly done some good research with the design. I use dual motors and home them independently with no problem.
The usual advise on here is to advise not to order any electronics (or kits of electronic)s as thing often change in the design. I don't think you will need the dual screws to be full length as you can move the nut mounting a bit further back on the gantry side and save about 200 mm of screw length.

I would also consider for the gantry HD ally profile say 90 x 45 two pieces one horizontal and the other on top vertical the slots in them are correct for BK12 bearing mount etc. so make it very simple.

Anyway just two sleeps for Xmas:beer:

Sorry to quote such an old post but isn't the hole spacing for BK12 46mm? Does it just work with the 45mm spacing on the extrusions? Definitely would save some work if so.

[AndyUK]

Evening Folks.

One of my original aims for this machine had been to help with the other half's glass work. We've made jigs, and aluminium bead making tools, but until now haven't touched glass itself.

I kinda expected to need a water cooling trough, and to use a diamond burr to grind the glass away. Recently though, we stumbled on some people using a scoring wheel without any of that faff and thought we'd give it a try. Wheel cost us a couple of quid and is a drag style.

I first probed the surface because it's not spring loaded yet, so you'll hear the machine doing some funky Z adjustments as it goes.

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https://youtu.be/YuUrgRtUUt0

Anyhow, she's delighted with the results, mainly because the CNC maintains a perfect perpendicular to the score line, so the pieces break out really nicely in comparison to amateurs cutting manually!!

Here's our first test piece where we cut a large hexagon and lots of small diamonds before a brief trip to the kiln:

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All float glass so far, we'll start using the good quality stuff next for a real project :)

[AndyUK]

Whilst I'm doing project updates... One of our other time sinks is being on the water. I'm currently rewiring our boat and thought it would be nice to give it a custom control panel. I've blanked out the identification area, but it was great fun to design and make this exactly how I wanted it.

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Being a sailor also comes with a drinking habit, so you also need a nice drinks table for the cockpit. We grabbed some appropriate plastic tumblers and used the CNC to carve perfectly fitting cupholders, and nicely inlay the hinges into some Sapele. The hardest part of this project was the varnish :/

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Finally, the tender needed some love too, so along with steam bending new gunwales I also CNCed a new transom for it. Don't ask my why we've called our tender floss - I'm not even sure I know myself.

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[AndyUK]

And last, but by no means least, my Daughter's Christmas present. I took a few months over this one, which probably says more about how little free time we get these days!

I saw the solid oak toy boxes from makemesomethingspecial (https://makemesomethingspecial.com/shop/bespoke-toy-boxes/) - and was utterly obsessed. I had to make one, and now I have an excuse to have a toy box around... So off I went to find some appropriate oak, and into CAD I went. Here is the result - although again I've removed her name which is carved in the front through the wonder of Google's magic eraser (hasn't it done an amazing job matching the grain?!) - Complete with the box's owner playing peak-a-boo inside. Don't worry for her hands, the hinges are rockler's torsion spring hinges, so the lid stays exactly where its left.

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One of the features I really love are the finger joints. Because I lack manual woodworking skills, I decided they had to be fully CNCed. So I chose the round the edges of the fingers to match the cutters radius on the internal corners. This meant not only rounding them in the profile cut, but also using a matched round over bit on the back face of each piece.

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And then of course the lid needed some inlays. I couldn't think of anything better than the Disney Winnie the pooh quote, so I went with that alongside some purple-heart purple hearts. Corny? Yeah. But cute, too.

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[MikeyC38]

Hi Andy
Amazing use for your cnc router - never thought about cutting plate glass using CNC. I have a big slab of 10mm float glass that I use for tramming the spindle on my machine because it is relatively flat. My machine is currently in its transport cradle since December 2021 when I moved house. Getting the garage sorted out now and just need 4 burly guys to help me lift it into position...

[nhan863240]

Great build!

Not sure if I missed it, but did you do any stress relieved given that you welded? If not, i assume residual stress would affect the structure overtime. I ve been asking this question on DIY facebook groups but havent received a good answer. Given that you are a physicist by trade I would love to hear your opinion on the matter.

Thank you!

[AndyUK]

Great build!

Not sure if I missed it, but did you do any stress relieved given that you welded? If not, i assume residual stress would affect the structure overtime. I ve been asking this question on DIY facebook groups but havent received a good answer. Given that you are a physicist by trade I would love to hear your opinion on the matter.

Thank you!

One thing to think about is where the stress comes from - Its all about the cooling and contraction of the weld as it goes from hot hot hot to room temperature. This is effectively quite a short term process, once the stress is there, it will cause strain in the material resulting in some deflection. There isn't particularly any reason for this to change over the period of years.... And then of course, we go and epoxy level / scrape / machine the surfaces to make them flat, so that's all done once the strain is there and accounted for.

But always ground yourself in the practical world - its all too easy to get lost in theory and what-ifs. Experience trumps most of it. Plenty of people around here have welded frames, and I haven't seen anyone have an issue with stress. Just be sensible and tack weld everything slowly and move methodically around the frame to avoid building up heat too much before completing the full welds - but thats standard welding practice anyway.

[AndyUK]

Wiring Diagram update, to include new control panel switches, a 10W Diode Laser, and 4th Axis drive (Step and Dir lines not shown yet, but you get the picture).

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[Nickhofen]

Thanks for sharing .
Happy new year to you Andy!

[Lee Roberts]

a 10W Diode Laser

Cool, so your using the machine as a diode laser engraver? Been thinking about this recently myself too :distracted:

[AndyUK]

Yeah, just a bit of a experiment really. £130 for a 10W 450nm Laser Tree 80 24V from their AliExpress store.

Made the first couple of cuts tonight - was a bit of a bitch to setup and I'm not particularly enjoying how dangerous it feels for my eyes (I have reputable laser Goggles etc, but I used to work with similar lasers in an optics lab so know how evil these things can be), and it's quite fumey too. That and the fire risk.

Having said that though, very happy with the results so far. Here was my first ever time running Gcode on the laser (UCCNC seems relatively capable, although clearly not designed with lasers in mind - there is a recent lightburn import plugin which is really helpful). Flipped the axis for the next cut and it looks fantastic - although in my first material test squares I ended up blasting through the 3mm ply and then on all the way through 20mm of MDF.... Whoops.

The below test text is about 50mm wide, took about a minute with a single pass at 3000mm/min 50% power.

Hopefully some point I'll do a summary post with a few complete projects, and more on the 4th Axis testing I've also been up to.


https://youtu.be/Rh5VqiiP9DE?si=_7JdKGh7pR9uXCO-

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Anyhow, Happy New Year all!