John's Alu Profile build

Hi All,

So I'm starting this thread quite a way through the build process. I didn't want to document the entire thing from the start as I knew this was going to take me a long long time.

I built myself a Momus CNC build some years back and got the bug, but that machine is pretty limited as it flexes all over the place (on the Z axis). It's also belt driven which is an absolute pain in the backside as the belt pulleys loosen over time. I initially wanted a machine for wood and after time started machining more and more aluminium, so the new machine I want to be two fold: rigid enough for working aluminium but with a much bigger footprint for working on larger hard wood projects. I also do quite a bit of diamond drag engraving on aluminium which the old machine isn't accurate enough to do.

I basically have been piecing it together bit by bit over the last couple of years, and at the current stage it's moving and wired, but I have some changes to make for sure.

The Gantry is 80 x 160 profile and its running on two 80 x 120 profiles in the Y axis.

Linear rails are all 20mm THK ( the black Y axis rails are Raydent(?) coated). I got all the higher end motion parts used (but they're in great shape).

The Z axis was a real Achilles heel of my old machine, terrible design, so this new Z axis was bought as a full unit from an old machine in Korea (used for IC production I believe) it is made from stainless for the most part and has 15mm THK rails and a THK ground ball-screw for movement and optical limit switches. I milled an aluminium backplate for it and mounted it to the Y axis blocks.

I have a Ground NSK ball-screw on the X axis, positioned on the top of the extrusion. I chose to do that as I wanted to get the Z axis as close to the rails as I could.

The Y axis is driven both sides with ball-screws (Chinese 1605) but I'm really not happy with those so I just ordered some 20mm (2005) ground ballscrews from TBI. I would have liked something better brand wise but I think they should be okay.

Most of this is probably overkill in a aluminium based router I know, but I want to get it as functional as I can really.

You'll notice I haven't got a base/table as yet, the reason being is I'm a bit undecided about that. I've been toying with the idea of mounting it to a wall (and have some blocks ready for doing that, but I'm struggling to decide. I really don't yet know how I could effectively level the wall surface in practice before fixing the machine to it (any advice would be greatly appreciated.)

The spindle looks like the regular cheapo chinese ones but I went with a company Jain Ken for this, it's 1.5Kw ER16 and has ceramic bearings, as far as I can measure it has no runout on it (!). Mind you my dial indicators aren't serious quality, but it's definitely accurate enough for my needs.

For VFD I went with RS510 from RS electronics, it works really well and is essentially a Teco 510 it seems.

I made up the control box from scratch, a linear power supply (70V) was made with a transformer, regulator plus capacitors and I put a soft-start on the incoming AC to smooth out the turn on a little.

The stepper drivers are all AM882 running at 8th micro stepping. I'm really impressed with these drivers, they're very smooth.

I'll figure out how to upload some images shortly, and add them here.

Here's a picture of the main machine as it is today.
Attachment 27712

Here's a couple of shots of the spindle and Z axis details.
Attachment 27713Attachment 27714Attachment 27715

The Z axis came with three optical sensors inside, I kept one in there as upper homing limit switch and reused the other two as home/limits for the Y axis, one each side. For mounting I machined a carrier from Delrin/Acetal. I'll probably replace this with aluminium at some point soon.

Attachment 27716

The plates which mount between the Y axis bearing blocks and the gantry were modified to fit a piece of aluminium L profile, this moves into the optical switch when homing.

Attachment 27718

For mounting the Gantry to the ballscrews on the Y, I had a local company weld me up some brackets to my design.

Attachment 27719

They made a bit of a balls of it to be honest, It's not square and I had to rework it by hand a lot. I can't weld so I didn't have much option, I really should learn to. Since I'm replacing these chinese ball-screws with ground screws from TBI I'm not going to sweat it just yet. Once the parts are here I can redesign this part and the motor coupling for each.

I'm using LinuxCNC 2.8 for this with kins, if anyone wants me to upload my .ini and .hal files let me know. It's working well so far.

So, as I said the spindle is from China, but seems to be much better quality than the regular ones, certainly run out and machining quality is amazing. Running at full pelt it is really smooth.

Here's the company if anyone is interested (no affiliation with them at all btw): http://www.jian-ken.com

The VFD is model RS510 from RS Electronics (no affiliation with these either): I'm really happy with the quality of this too. It's actually rated for 2.2Kw but I thought some overhead would be a good idea. Definitely one to add to the list for the other Chinese spindles too.

Attachment 27720

Part of the reason it's taken me so long, apart from sourcing all the parts here and there, is the fact I had to build myself a little workshop to house it in.

Attachment 27721

I still have a bit to do to finish this place, insulate it in between the stud walls and plywood the internal walls, but it's dry and solid.

At the right hand side outside you can see the six inch blocks. I don't know if these exist in the UK or not but my idea was to build a wall with these on the flat and bolt the entire CNC to it with the Y rails running parallel to the floor. If anyone has an experience I'd appreciate some advice.

Attachment 27722

I'm really not sure how I would level a wall to the degree necessary to accurately fit this too, but maybe I'm overthinking it.

As a test, I knocked up a pencil holder out of some delrin and some drill rod, with a spring for applying pressure and for accounting from deviations in the surface. It worked great, but the chinese ball-screws really aren't great (noise, vibrations etc.)

Attachment 27723

I actually sourced angular contact bearings for the BK12(?) blocks, so I might now have to sell those too.

Here's a snap of the internals of the control box, the main cabinet was sourced from RS electronics and I fitted the rest after bench testing. I probably could have used a smaller case but I have plenty of space so I don't mind the extra space from a cooling perspective.

Attachment 27727

I went with GX 16 type pins for termination of the wiring both on the motor/sensor side and the case/enclosure side. The wiring is done so that the case side takes the Sheild of each wire to earth.

Attachment 27728

I think that's all I have for now guys/gals.

A couple of questions I have, then, if you don't mind:

+ Playing with the machine as it stands, there's a lot of resonance from the hollow sections of the profile, for the Y profiles I intend to either fill with sand or maybe epoxy/granite. With one end almost closed at the front and the significant vibrations from the less than stellar 1605 ball screws these are resonating like an instrument at the moment. I'm sure this will hurt surface finish as I can clearly feel the transmission through to the spindle by hand, but I expect a sand fill will help since these parts won't need to move.

+ With regards the Gantry, I'd imagine filling that with epoxy/granite will be much too heavy for my motor/screw combo (480oz/in plus double nut 2005 ground ball-screws). Has anyone any experience with filling the voids of profile with expanding foam to dampen vibrations/resonances? I suppose I could test a piece but I don't have any spare material to hand. I wonder if something like silicone fill could work if it could be done cheaply enough.

+ Also would be keen to hear any input from the idea of bolting this entire CNC to a concrete wall, specifically how I might line everything up in practice. I like the idea of gravity pulling away chips and using less floor space but could just go for the traditional setup.

Hi John
Regarding vertical mounting you will have to build yourself a substantial base, if you make another post asking for ideas for designing a vertical assembly machine Dean(JAZZCNC) might give you some advice regarding this, he has a video of one of his larger builds but i couldn't find it.
Regards
Mike

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Originally Posted by mekanik

Hi John
Regarding vertical mounting you will have to build yourself a substantial base, if you make another post asking for ideas for designing a vertical assembly machine Dean(JAZZCNC) might give you some advice regarding this, he has a video of one of his larger builds but i couldn't find it.
Regards
Mike

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Okay, thanks a lot, I'll have a think about some options.

John,
I haven't tried this but have wondered if polystyrene concrete could be used to damp the gantry without it getting too heavy. I found an article once (don't have it to hand I'm sorry) that described using up to 60% by volume of polystyrene beads (you can buy them for making bean-bag furniture) to make concrete for light-weight structures. It's still quite strong at that percentage and I think the density came out at a little over 1Kg/litre.

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Originally Posted by Kitwn

John,
I haven't tried this but have wondered if polystyrene concrete could be used to damp the gantry without it getting too heavy. I found an article once (don't have it to hand I'm sorry) that described using up to 60% by volume of polystyrene beads (you can buy them for making bean-bag furniture) to make concrete for light-weight structures. It's still quite strong at that percentage and I think the density came out at a little over 1Kg/litre.

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Hey. Thanks! That's quite interesting. I was thinking of something similar with perlite and concrete or epoxy. I was told that concrete may react with aluminium though somewhere but I can't recall where exactly. Does a anyone have any insight on that? On this note I was looking at some local companies that sell recycled tyres, chipped up for playgrounds. I was thinking that could make a good aggregate for a damping composite maybe, with either epoxy or liquid platinum cure silicone to bind the chunks together in a similar way to making epoxy/granite.

It sound like some tests might be in order, luckily I'm an acoustics specialist with oscilloscope etc here so could at least test a few solutions on a small scale.

Quote:

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Originally Posted by mekanik

Hi John
Regarding vertical mounting you will have to build yourself a substantial base, if you make another post asking for ideas for designing a vertical assembly machine Dean(JAZZCNC) might give you some advice regarding this, he has a video of one of his larger builds but i couldn't find it.
Regards
Mike

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That would probably be this 8x4 then. 10 x 5 with a Vacuum bed will be coming soon if I ever get out of this bloody house again.!!.

The vertical machine works amazingly for large machines with no downsides other than cannot use it as a bench. The advantages are many and I wouldn't go back to a horizontal machine if larger than 4x4. That said I'd still have a vertical machine under 4x4 for some of the hidden benefits like longer tool life and better chip management but below 4x4 the space-saving isn't so great.

Regards the filling of tubes then I've tried sand and while it does help a little it's not a massive difference. Don't fill tubes with concrete because it can shrink, it also doesn't mix well with aluminum. Expanding Foam and Silicone etc don't do diddly squat so don't waste your time money.

The best thing I found is to use a thicker wall tube in the first place and brace it well. Regards the aluminum profile then if you use HD version then you shouldn't have any issues with vibrations and I don't think to fill the voids with Epoxy granite will dampen to any great degree but it will certainly affect performance because of the extra weight.

https://www.youtube.com/watch?v=wJB_75bLEIM&t=8s

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Originally Posted by Evengravy

It sound like some tests might be in order, luckily I'm an acoustics specialist with oscilloscope etc here so could at least test a few solutions on a small scale.

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You're the man then! I like the idea of bendy concrete made with old tyres :excitement:

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Originally Posted by JAZZCNC

That would probably be this 8x4 then. 10 x 5 with a Vacuum bed will be coming soon if I ever get out of this bloody house again.!!.

The vertical machine works amazingly for large machines with no downsides other than cannot use it as a bench. The advantages are many and I wouldn't go back to a horizontal machine if larger than 4x4. That said I'd still have a vertical machine under 4x4 for some of the hidden benefits like longer tool life and better chip management but below 4x4 the space-saving isn't so great.

Regards the filling of tubes then I've tried sand and while it does help a little it's not a massive difference. Don't fill tubes with concrete because it can shrink, it also doesn't mix well with aluminum. Expanding Foam and Silicone etc don't do diddly squat so don't waste your time money.

The best thing I found is to use a thicker wall tube in the first place and brace it well. Regards the aluminum profile then if you use HD version then you shouldn't have any issues with vibrations and I don't think to fill the voids with Epoxy granite will dampen to any great degree but it will certainly affect performance because of the extra weight.

https://www.youtube.com/watch?v=wJB_75bLEIM&t=8s

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That's awesome! This has given me some ideas for sure... Design wise it's not a million miles away from mine, I really wish I could weld. Maybe I can think of something I could make work using aluminium profile.

Ten four on the cement filling. I think I'll go with sand on the Y rails that don't need to move just for the added benefit, and try some test pieces for composites on the X gantry, to see if it's worth the hassle. I can't recall if it was HD rails, it was this type of profile from Dold Mechatronic: https://www.dold-mechatronik.de/Alum...-type-groove-8 maybe there is heavier type out there and that was my mistake.

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Originally Posted by Kitwn

You're the man then! I like the idea of bendy concrete made with old tyres :excitement:

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Thanks. Sure, I'll do some more in depth reading and maybe some tests soon, the complication at the moment is getting out of the F'ing house to get materials but gives me chance to do some research if nothing else.

I came across a guy on another CNC forum that recommended bitchumen (tar) plus sand, that could potentially be a cheap and available solution, if it isn't too heavy that is. Maybe roofing tar plus rubber chips. Certainly it's common to use roofing bitchumen sheets (old school roofing felt) in acoustic dampening solutions in a studio environment, I see no reason why it wouldn't transfer here, in theory.

Silicone would likely be expensive but should be quite efficient, maybe recycled rubber plus a binder might help. It's always going to be a tradeoff of weight vs dampening factor for a gantry though.

It's simple enough to test smaller pieces in practice though; with a contact mic/measurement mic and some shorter pieces of profile and an oscilloscope, I have some 80x80mm profile I could donate to the cause so I could side by side a few possible solutions as an experiment. Could be useful to see what approaches might work down the line.

At the moment, I'm just awaiting the new ballscrews to arrive so I can get rid of these cheaper ones.

Thanks for chipping in guys, appreciated.

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Originally Posted by Evengravy

That's awesome! This has given me some ideas for sure... Design wise it's not a million miles away from mine, I really wish I could weld. Maybe I can think of something I could make work using aluminium profile.

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Welding isn't that hard, esp if you can get your hands on a Mig welder. You can even hire them from some a decent hire shops.
The welds don't need to be industrial strength. Steel is very forgiving so it allows you a few attempts if get it wrong and along with a grinder you can hide all your screw ups away.

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Originally Posted by Evengravy

I can't recall if it was HD rails, it was this type of profile from Dold Mechatronic: https://www.dold-mechatronik.de/Alum...-type-groove-8 maybe there is heavier type out there and that was my mistake.

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That is the ITEM "L" section the "L" stands for light. It's exactly what you see on that vertical machine but I'm using the heavier version which doesn't end with "L".
However, I've used the "L" on many machines and it works perfectly fine so I wouldn't be too worried.

If you are going to do vibration tests then I wouldn't waste time testing individual pieces of profile or steel etc off the machine because all that matters is the tool. Testing at the tool is the only thing that matters IMO. You'd be better investing time on designing a strong Z axis.

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Originally Posted by JAZZCNC

If you are going to do vibration tests then I wouldn't waste time testing individual pieces of profile or steel etc off the machine because all that matters is the tool. Testing at the tool is the only thing that matters IMO. You'd be better investing time on designing a strong Z axis.

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Yea, that's a good point. I did a bit more reading around the subject and a guy on CNC zone recommended pea gravel in the non moving parts and nothing in the gantry, for now. I'll try that first and see where it is. I actually have a MIG that I bought years ago but never got around to learning to use the thing, a gas-less 150 from draper (I'm not sure if they're much good). It's been shelved in my dads place for years but maybe it's time to dust it off.

I think the Z axis I have is pretty solid though, it's foundation is milled from stainless. I know the opposite arrangement than most recommend, with the rails on the z plate which seems to be preferred, but it was a simple solution for me. I've tried to keep everything as close to moving bearings and having as little overhang as possible. The Z only has 100mm of travel but after using my other machine for a few years I realised I've never needed to mill anything over a couple of inches thick so the z overhang was really compromising the strength. That plus the momus design is not very good generally. Live and learn. I thought it would be a good idea this time for me to keep the gantry and Z axis as tight to the part as is feasible.

It's a shame about the profile, maybe I'll change it for something heavier but at this stage I might just run with it and see how it does, should be easy enough to swap it out for a heavier profile down the line.

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Originally Posted by Evengravy

I think the Z axis I have is pretty solid though, it's foundation is milled from stainless. I know the opposite arrangement than most recommend, with the rails on the z plate which seems to be preferred, but it was a simple solution for me. I've tried to keep everything as close to moving bearings and having as little overhang as possible. The Z only has 100mm of travel but after using my other machine for a few years I realised I've never needed to mill anything over a couple of inches thick so the z overhang was really compromising the strength.

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There's nothing wrong with rails on the rear plate, I've built dozens of machines using both methods and neither is better than the other because the difference between them is hardly anything and any advantage one as over the other is mostly dependant on machine design and user needs.
In your case with a short Z-axis, it's the best method because it allows you to make the most out of a short-stroke while allowing you to keep the gantry low and squat giving the best strength.

Edit:

Don't worry about the profile it will be fine. If you using my "L" Gantry design just make sure you bolt it together well.

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Originally Posted by JAZZCNC

There's nothing wrong with rails on the rear plate, I've built dozens of machines using both methods and neither is better than the other because the difference between them is hardly anything and any advantage one as over the other is mostly dependant on machine design and user needs.
In your case with a short Z-axis, it's the best method because it allows you to make the most out of a short-stroke while allowing you to keep the gantry low and squat giving the best strength.

Don't worry about the profile it will be fine.

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Ah that's good to hear, I didn't go for the L design you have no, I wish I had of kicked around here before but that does look like a better solution than mine, unfortunately I'm quite a way through the build so at this point I'm just looking to get her done and running. I don't know if you would have any comments on the design as it stands? There's a few places I could reinforce around the gantry connection to the Y axis plates etc. I'm sure I can figure something out there.

I could always beef up the gantry with some steel plate on the back-side too, if that would help. I might just get the base/table done next and see how she does though.

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Originally Posted by Evengravy

I could always beef up the gantry with some steel plate on the back-side too, if that would help. I might just get the base/table done next and see how she does though.

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I would look to beef up and brace the gantry ends but other than that it's nice and stiff looking.

That Z-axis is spot on for the size and you have half-decent material size. You won't get a much stiffer setup.

NOW just turn it on its side, or stand on its end and bolt to that wall.!!! . . . . You'll love it.

Thanks mate I'll do that,

Once the steel shops open again I'll have a crack with the MIG and see how I get on.

So,

New ballscrews have arrived, TBI motion ground 2005 with double nuts. These ballscrews have BK15 mounts at both ends rather than a floating end and each BK15 holder, four in total, has a pair of Japanese 7002 angular contact bearings. These parts were bought lightly used from the same seller that I bought a lot of the other parts from in South Korea, but are clearly much better than the Chinese ones that I'm going to pull off the Y axis. One of these screws will be on each side of the Y axis as before so it should improve the smoothness of motion and the extra thickness of the screw (going from 16mm to 20mm) should enable me to increase the speed of the rapid movements a little without encountering whipping.

Attachment 27781

The only downside of the change so far is that I've lost a bit of travel on the Y axis, down from just over 1100mm to just over 1000mm. I'd rather have the piece of mind of these motion parts than the extra cutting envelope so I'm okay with it.

As a result I've needed to redesign a few parts though. As per Jazz suggestion I've added a new bracing for the gantry which will tie in to the Y axis linear bearing plates. This part only braces towards the back side of the gantry, as the new ball-screw connection will be made to the front side via a plate as shown below. I might figure out something for the front too at a later date.

Attachment 27779

I've designed some new shoes for the ballscrews to fix to to mate them with the Y axis profiles.

Attachment 27778

I've also rethought the design for connecting the ballscrew to the Gantry. I was never too happy with the previous welded solution, they were a mess.

Attachment 27777

Lastly, since I've moved up to a larger screw my motor mounts have to change too. These attach to the end of the Y profile on each side and carry the Y motors.

Attachment 27780

Since I can't buy materials at the minute I've decided to try to get all of these laser cut in the UK and shipped over. The company are running but with minimal staff so it might take a while to organise.

Gantry to ballscrew mating part will be made of 15mm mild steel laser cut and I'll paint that later. The rest will be laser cut from 10mm stainless steel. That's the plan at the moment, it's hard to get companies to do much at the moment so we'll have to see.

Don't understand why you are making the Y ball screw plate and the brace plate separate.? This could be made as one piece and will be stiffer and easier to fit.!

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Originally Posted by JAZZCNC

Don't understand why you are making the Y ball screw plate and the brace plate separate.? This could be made as one piece and will be stiffer and easier to fit.!

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Hey,

I designed it this way just to give me scope for adjustments in each degree of freedom. I couldn't think of a better way of doing it to be honest, open to suggestions though.

I could get both parts made up from mild/bright steel and once everything is lined up get the joints welded. I picked up my MIG today and dusted it off, maybe I can get good enough with some practice to get it done myself.

Attachment 27785

Also there's scope to brace between the front and side section with some triangulated pieces.

Attachment 27786

Honestly not too clear how I could make it in one piece, but I'm probably being blonde...it's been known to happen.

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Originally Posted by Evengravy

Hey,

I designed it this way just to give me scope for adjustments in each degree of freedom. I couldn't think of a better way of doing it to be honest, open to suggestions though.

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Ah makes a bit more sense now. I was working on your old setup and seeing all those holes which matched the profile ends I thought was fastening into ends.

Carry on.!! . . Lol

Edit: The drop bracket still needs some bracing thou.!! or a redesign of the whole thing.!.

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Originally Posted by JAZZCNC

Edit: The drop bracket still needs some bracing thou.!! or a redesign of the whole thing.!.

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Yea, I was planning some welded triangulation braces between the two parts once it's all aligned properly, the overhanging section that mates with the ballscrew is annoying me but I'll come up with something to strengthen it up. Front plate will be heavy (15mm) but I know that will be a weak spot for flex. I'll play around with the design a bit more in CAD.

Quote:

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Originally Posted by JAZZCNC

Edit: The drop bracket still needs some bracing thou.!! or a redesign of the whole thing.!.

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Hey, so I've decided to go back to my existing design of the gantry to Y ballscrew connection which was 10mm steel plate welded and braced with 10mm triangular plate sections. After testing this arrangement on the Chinese screws for play, measured at the tool with my dial indicators I'm quite happy with it strength wise so I have redesigned the same arrangement to fit the new ball-screws. The current layout has between 0.02mm and 0.03mm of play which is largely coming from the ballscrew nuts themselves, you can feel a good bit of play by hand in the ball nuts when these are off the machine which does tighten up significantly when both screws are in the machine (weirdly), but I definitely got unlucky with these Chinese ball-screws compared to what others seem to get. There's noticeable bends in them too so out they go. Bare in mind the current ballscrews are running with angular contact bearings in the BK12 holders, which I bought after the fact, so those bearings tighten up the play in the Y. Initially play was in the order of 0.1mm+ in my measurements before and fitting angular contact bearings. I can't feel any play at all by hand in the new ground ball-screws so I'm confident they'll be a big improvement.

One catch with the new design is that I'll need to machine a ball-screw nut mount for the new ball-screw, one each side. Would anyone here be able to machine this part for me (x2) out of Aluminium for payment? I'd rather spread work here than a bureau service if anyone is free/able/willing.

I don't think my Momus will be accurate enough to do it to this depth to be honest, there's just too much play in the Z (part is roughly 57mm x 65mm x 70mm from Ali (6061/6082 etc))

Failing that I'll have to consider milling it in thinner 25mm sections bolted together until I can machine it myself from a single piece when the machine is in situ, but I'd rather get it done right the first time if possible.

I still need to consider the bracing of the gantry to the Y bearing block plates, but I'm happy enough I can do that after the fact pretty simply and am considering an adjustable design there.

I'm leaning towards setting this up in the standard horizontal arrangement atm, reason being I'm thinking of running high flow flood coolant on it and it's easier to manage that way.

After getting no response from the laser cutting service on quotes I decided to have a route around in my stock and found some appropriate stock to mill some of the new parts myself.

Yesterday I went ahead and milled two new motor brackets with spacing to suit the new Y ballscrews. Material is 6082 Aluminium which machines rather nicely with a single flute carbide end mill, I just have to slow things down a lot on my Momus CNC and use small diameter cutters as the Z axis is prone to flex.

I can still achieve pretty accurate results though, it just takes time. I can't wait to have a stronger machine that can make use of adaptive tool-paths.

Attachment 27810Attachment 27811Attachment 27808Attachment 27809

I hand tapped threads with the aid of my tapping guide, I've had some bad luck in the past with using the battery drill for tapping and since it's so difficult to find materials at the moment I was happy to take my time to avoid any broken taps/ruined parts.

Whilst I was at it I milled four new feet, which connect the Ball-screws to the profile. Stock is 10mm thick and is set up so I can align the side of the BK15 holder to the top of the profile. These are tapped with M6 thread in four locations for the BK15 to bolt to with 45mm socket head bolts. There are then two 5mm fixing points for fixing to the profile. I may hide some countersink bolts under the BK15's too, for now it's fine.

I went ahead and ordered two ball-nut carriers from a custom CNC bureau service, so I can keep moving on this. They should be here in a week or so I think.

So, Friday I managed to get some new laser cut steel through the post from a crowd in the UK.

These parts will replace the current steel brackets which connect gantry on both sides to the ball nut holders. I used this as an opportunity to try welding for the first time. Please don't hammer me on the welding, I know it's shocking but this was my fist go at it and I've learnt a few things. One my 100A mig isn't nearly powerful enough for material this thick and, two; buying cheap gasless flux cored wire is a big mistake. If anyone is interested the Super 6 flux cored mig wire is something to avoid for a beginner at least. It creates plumes of black smoke, spatters like crazy (yep polarity is correct) and doesn't pool up very-well. If were to run the MIG again, I'd probably look to get some lincoln gasless flux cored wire, it seems to be well reviewed. Seems a bit pointless for this project, in future I'll be sticking to trying to learn a bit of ARC welding as I'm mostly interesting in sticking thick pieces metal together.

Essentially I've built two of these and each is just tacked at this point and I intend to grind this mess back and get up to speed with the arc and come back to it. It does seem to be fairly strong though. Importantly it is square and key surfaces are flat so it a definite improvement on the last version a local company made, which were neither flat nor square (but welded better for sure). I'll be able to move along with the other bits when they arrive.


Custom ballscrew nut mounts are on the way, then we can mount and test these new ballscrews!

One I can confirm that everything lines up the way it should, I can use the steel from the old ballscrew mounts to practice some arc welding before coming back to these. At the moment getting steel is tricky. I intentionally didn't weld on the inside so I can tackle that later, after some practice.

Attachment 27967Attachment 27968Attachment 27969

I'd be very happy with that as a first welding attempt - nice one! But yeah MIG isn't going to be best for that material size - I'd be surprised if it has enough penetration.

What's the phrase? Grinder and paint make me the welder I ain't.

Thanks Andy! it seems to be strong enough but I'd guess it's penetrated around 1-2mm into the base metal, or so (looking at the front corners). I can pass over the inside with the ARC once I get the hang of it too so I'm not too worried at the minute, I was more nervous to stuff up the alignment to be honest but it's bang on where it needs to be.

I've been playing around with the ARC a moment ago on some scrap. I like it much more than MIG as a process so far, at least I can get a good pool going with it. Enjoying that a lot.

I'm hoping to weld up a steel frame of some sort so it's worth learning something new whilst I'm about the house a lot.

This morning two custom ballscrew nut mounts arrived from the CNC service, they came out really well so I followed on to test fit these and the newly welded (ahem) brackets. Attachment 28020

With a little to and fro to swap parts out I'm glad to say it all fits as well as I can expect, and boy does the thing feel much more solid now.



I had to massage the brackets a little on the corner to give some wiggle room by adding chamfer the corner of the L to give a millimeter or two clearance.

Attachment 28021

I'm now just awaiting the new anti-backlash couplers to mate the motors to the new screws and this part should be done. It's been a bit of extra work, but so far I can feel the improvement and I'm glad that I took it on.

If everything goes smoothly then I'll be removing these steel brackets and adding some more internal welds just to beef them up a little before painting them black and refitting. I'll need to start designing the table soon, I may be back to get some advise from you all when I get around to that part.

Attachment 28022 Attachment 28023 Attachment 28026

Hi John, It's looks great. In relation to the resonance you are experiencing in the Y axis are you running the machine with the Y axis unmounted to a surface or base? Do you only experience this when running the machine with the spindle on or off? Your selection of steps per revolution will also come into play with resonance as I myself experienced something similar. Endless tweaking and trying different combinations of steps per rev and mucking about with acceleration and deceleration settings got rid of it for me. Where are you based in Ireland? Liam.

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Originally Posted by AndyUK

I'd be very happy with that as a first welding attempt - nice one! But yeah MIG isn't going to be best for that material size - I'd be surprised if it has enough penetration.

What's the phrase? Grinder and paint make me the welder I ain't.

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Mig is more than capable of welding that material, but 100A isn't. It would need 250-300A and thick wire. The trick with Mig is setting the wire feed correctly.

Also when your butting 2 pieces like you have if you grind a chamfer on each edge where you want the welds it will give you a stronger weld as you have larger weld area, it also gives you a flatter weld with hardly any grinding required.

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Originally Posted by JAZZCNC

Mig is more than capable of welding that material, but 100A isn't. It would need 250-300A and thick wire. The trick with Mig is setting the wire feed correctly.

Also when your butting 2 pieces like you have if you grind a chamfer on each edge where you want the welds it will give you a stronger weld as you have larger weld area, it also gives you a flatter weld with hardly any grinding required.

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Hey, yes sorry I was referring to my MIG in particular, I'm sure with more current it would work absolutely fine. Ten four on the chamfering, I'll keep that in mind for future.

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Originally Posted by Mister Mills

Hi John, It's looks great. In relation to the resonance you are experiencing in the Y axis are you running the machine with the Y axis unmounted to a surface or base? Do you only experience this when running the machine with the spindle on or off? Your selection of steps per revolution will also come into play with resonance as I myself experienced something similar. Endless tweaking and trying different combinations of steps per rev and mucking about with acceleration and deceleration settings got rid of it for me. Where are you based in Ireland? Liam.

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Hey, thanks. Currently no base, I'm still considering the best approach for building the base at the moment. Some are quite unconventional lets say but I want to run high flow flood coolant for milling aluminium so I'm going to think about liquid capture etc. I'm going to try and CAD design some ideas over the weekend. I'm a bit limited with the current lockdown in sourcing what I would need anyway so no stress just yet. The vibration was really just coming from the screws themselves without the spindle running, which weren't great quality and not straight either. So, partly crappy ball nuts with lots of friction and play, partly non straight ballscrews plus a coupled hollow cavity = resonance. I'm not too concerned with the resonance part, that's in my field of expertise (I'm an acoustics/audio specialist) more concerned with the smoother motion that the new screws will provide plus hopefully less play (I'll need to measure that again today). I intend to fill the Y rails with either sand, pea gravel or epoxy granite to get rid of that resonance. I'll probably go cheaper options first and see where it is. I can measure the natural resonant frequency pretty easily and try to tune around it too. I'll keep those points in mind for sure though on tweaking, thanks for that.

I'm based in Donegal buddy, you?

I'm down in Co Meath for my sins.... Yes the Lock Down is a bummer but I believe we will be let out gradually from the 18th... Plenty of time to do design work! I forgot to ask what the cutting area of your setup is? It's a decent build for sure. I would 100% recommend flood coolant doing any serious metal machining or mist for lighter work otherwise you will get a pain in your ass replacing cutters! I settled on rack and Pinion after trying belt and lead screw. Both turned out to be disasters.No way I could afford 2.8 Meter Ball screws!! My Rig has been sitting idle for 2 years and only recently am I getting the Itch to start playing again.. The only bonus of the lock down!. Feel free to give me a shout it your stuck with anything. I have made shit load of mistakes building my setup but you live and learn and it may help you from falling into some of those pit falls!!!