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charlieuk
22-03-2017, 12:20 AM
A few years ago I built myself a large router for cutting stand up paddle board blanks (pic bellow) however I have now got the need to start cutting other things so would like to start the process of designing and building a second machine.

The main thing the machine will be used for will probably be for cutting moulds for various things from aluminium with a high quality surface finnish. The moulds I will be cutting will be fairly large so feed rates are important. (also pictured being cut on a china machine I have been using however in surprisingly surface finnish isn't great)

At the moment I'm thinking 1220 x 600 cutting area with at least 100mm of useable z travel

I am thinking or running the gantry down the length of the table rather than width if possible so I can use the machine with full sheets.

obviously ball screws all round

then I would like to use the cs-labs cysimo again the same as on my last machine.

I'm open to suggestions, I would quite like to use ali extrusion again for the build as I'm set up for it and have quite a few bits kicking around however I also have a good amount (from memory) 90x90x2.5 box steel that I could passably use if needed for the build if I need to go the steel route.

when I can figure what exactly Is going to be best I will have a go at starting to draw it up on cad.

charlieuk
25-03-2017, 12:46 PM
I haven't gone far with the design at the moment but wondering about doing something along these line with basically the gantry of a 8x4 machine but with only a 600 wide cutting area.

is it feasible to go with this lay out?

Boyan Silyavski
25-03-2017, 01:51 PM
Using extrusion will speed up the build immensely. if i am building a small multi function machine for me, thats exactly how i would do it, wider Y and shorter X, so i can use it for bigger jobs.

JAZZCNC
25-03-2017, 09:20 PM
If your wanting high quality surface finish in aluminium then that setup is wrong way to go about it really. Unless the gantry is very heavily built it will vibrate along the long length and affect surface finish. Over building just costs more money so best avoided.

Would be much stronger traveling down the length with nice short stubby gantry.

charlieuk
25-03-2017, 10:36 PM
How over built are we talking? the ability to take a full sheet of ply is worth something. If it wasn't the space restrictions I have I would be building a 8x4 machine in which case I guess I would be building the stronger gantry anyway.

I guess the only other way would be to have the gantry going down the length on the raised rails but have it only supported at ether end so a sheet can be passed under it?

Boyan Silyavski
25-03-2017, 10:45 PM
Dean is right, if you expect perfect finish on aluminum you will have to overbuild like mine build. Ok maybe not so much but simplest will be 2x 100x100x3 box section welded together. Or something in the same range of strength at least. But also have to be fast so you can do HSM with light fast passes. But honestly i dont see how over that span you will go under 100kg gantry at least. My gantry is 180 kg for example with all mounted.

Dont you have now a large machine to do that stuff??

charlieuk
25-03-2017, 10:53 PM
my large machine only has a width of 760 and was not really designed for much more than cutting foam fast.

charlieuk
25-03-2017, 11:16 PM
something along these line but I guess the side rails would need to be more over built than this but I'm not sure it would be any better.

JAZZCNC
26-03-2017, 11:17 AM
How over built are we talking? the ability to take a full sheet of ply is worth something. If it wasn't the space restrictions I have I would be building a 8x4 machine in which case I guess I would be building the stronger gantry anyway.

Charlie You said cutting Aluminium to high surface finish, ply is different thing altogether. Your first design will quite happily cut ply but aluminium is different matter. The Stiffness required goes up quite lot and to have high quality surface finish it goes to another level. Anything you can do to lessen resonance will help with surface finish so long hollow flexi beams are best avoided.
This means using thick walled heavily braced and stiffened design which opens up complete new set of issues regards ballscrews,servo, controllers etc which get expensive quickly.

If your spaced limited look at building vertical. You'll get 8x4 in the same space as your First machine. Something along the longs lines of this which I'm building at minute thou for high end aluminium I'd change the design slightly and do away with gantry sides.
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charlieuk
26-03-2017, 11:39 AM
I had wondered about vertical but it wont help much as I don't have much wall space spare to push up against, certainly for 8x4. I guess I will ether have to go for less quality on the aluminium or for go the ability for full sheets.

charlieuk
26-03-2017, 12:41 PM
what would be the best I could hope for quality wise on aluminium for something bassed on the first design ether made from ali or a welded steel frame.

Boyan Silyavski
26-03-2017, 07:54 PM
For cutting aluminum if gantry is from alu profile, then make your gantry as Dean makes his machines, L shaped. To simplify things for you, check data for 2x 100x100x4mm or 200x100x4mm on the span of your intended gantry and that should be your minimum, aluminum or not. I am talking about the moment of inertia of the beam.

I have a complete drawing of my machine in Sketchup which has 1300x2600x200 mm working area. Later i revised it again piece by piece as i sold plans to some interested people and reflected the changes and what i have learned from the build and even further simplified some stuff for easier experience of putting it all together. Also corrected some details for the cheaper Chinese servos to fit there. I believe $ per strength my machine is an incredible value, where 700kg of metal do what normally 3 tons of metal do. I was contemplating also to redesign all instead of Sketchup to make it in NX or other CAD. So its easier to visualize and make a manual with instructions how to put it together.

In other words i dont mind giving the CAD for free but in order to update it with variants like L style gantry, etc. its an enourmous work. So i have to be stimulated to develop all that further, as its absolute stupidity for people again and again to try to reinvent the wheel for months when i have spent half an year designing fast and strong CNC which i know every little detail about it. The fact that i could machine mild steel 1mm DOC with Z axis fully extended and have perfect finish should speak enough about the quality of all. I am not selling you sth here, but if you want to save time and effort and help further with the project, PM me and we can arrange sth.

charlieuk
26-03-2017, 11:59 PM
Thanks for the offer but for me at least part of the challenge and fun is designing the machine and certainly for me as the design process in fusion is a great way to get used to learning the program.

I have just had conformation the steel I have at home is 100 x 100 x 4 or 5mm so there more than enough there to build what ever I want if needed but would prefer to probably stick with alli still for the most part if possible to speed the build up as getting it done in a timely manner is just as valuable as any cost saving for me as time is quite valuable.

although saying that the thought of being able to build a machine from free materials does have a slight draw to it what ever build I go for.

have there bee any other solutions to being able to pass a full sheet through a machine that I have not thought about that would allow the high quality ali cut.

not wanting to have to go up to the expense of servo and crazy electronics is the size then the limiting factor for good aluminium cuts?

JAZZCNC
27-03-2017, 12:17 AM
have there bee any other solutions to being able to pass a full sheet through a machine that I have not thought about that would allow the high quality ali cut

Charlie there is no cutting corners when it comes to having high quality finish in Ali. The machine needs to be Strong and Dense which by nature of the beast means heavy and when talking large format like 8x4 gets very heavy and expensive quickly.! . . . . Rush into this without good design and you'll regret it trust me.!
Boyans machine is strong and heavy but nothing special in it's design, Even if he think's it is.! . . . However he's correct that no point trying to re-invent the wheel so if you havent got room to go vertical then stay with conventional design and just build it strong.

charlieuk
27-03-2017, 12:24 AM
I wouldn't expect to cut corners just lower perhaps lower my expectations. The moulds I want to cut have to be hand finished, I guess it will just be how much work I want to do that is the question.

So to get the good quality with out going to steppers I'm just going to have to keep the gantry short?

or lower my expectation on the aluminium for the ability to feed a full sheet through.

Boyan Silyavski
27-03-2017, 01:39 AM
Charlie there is no cutting corners when it comes to having high quality finish in Ali. The machine needs to be Strong and Dense which by nature of the beast means heavy and when talking large format like 8x4 gets very heavy and expensive quickly.! . . . . Rush into this without good design and you'll regret it trust me.!
My machine quickly made me spend a lot of money. Initial plan was 1300x1300. making it full will cost around 2k more, including materials and parts. Maybe even a bit more. I knew that from the beginning and decided its worth the effort.



Boyans machine is strong and heavy but nothing special in it's design, Even if he think's it is.! . . . However he's correct that no point trying to re-invent the wheel so if you havent got room to go vertical then stay with conventional design and just build it strong.

Not that the machine is sth original in it self. We have seen similar and i have been inspired from similar.
But i believe that still there are really a couple of Great things about the design:
-$ per performace and generally all was optimized to save cash from here and there
-ability to DIY at home with only cut off saw and Mig gun.
-absolute minimum of milled or laser cut parts
-no vibrations, yes it gives the thump sound when hit with a hammer , not the ring sound
-Z axis is absolutely my original design with lowest overhang i have seen around and even ignoring the aluminum spindle enclosure machine will perform similarly. In other words this design removes the need of double gantry type machines, as they will not add sth very benefitial on the table, when both compared

The most special thing was that i did not do any mistakes so cost was as expected :-) and the performance met my expectations.

I still want to see a DiY machine that weights 800kg, has a work area of 1300x2600x200 and mills in steel with Z fully extended without ringing and perfect finish with 3kw spindle. Ok,will stop bragging, its obvious that i love my machine :beer:

Of course it couldn't have been able to happen without the help of others, Dean and Johnathan mainly.

charlieuk
28-03-2017, 01:24 PM
I know it may not be exactly the perfect way to do it but I'm still trying to think of ideas to allow me to achieve both goals and was wondering about doing something like in this pic wether its from ali or steel and that is to have some removable plate that bolt to the side that interlock into the frame that would give extra stiffness for when I want to cut ali however could be removed as and when I want to cut ply. This would also allow me to use the narrow gantry layout.

is it a workable idea or not worth the effort?

routercnc
28-03-2017, 06:44 PM
Hi Charlie,

That closer plate would be very expensive, especially aluminium. Is the idea that the ply panel would hang out through the gap?

The problem with that approach would be making sure that the rails mounted on top of the long extrusions did not see any load / deformation when the closer plate was added. I think if you put a DTI onto them and mounted / demounted the closer plate the rail would move as you tighten the bolts. Best to get it all rigid, using epoxy levelling if desired, then leave it alone.

The other issue would be the stiffness in the lateral direction (i.e. towards and away from the other long side) would still be low, even with the closer plate. Usually this is helped with supporting posts which have some section in the Y direction - for example short extrusions of the same dimension as the long extrusion but turned on their end . . .or if done in steel then box sections turned on their end.

Google 'Joes 4x4 hybrid' (cnc zone) for machines in landscape format rather then portrait format - not saying I'd go with a machine like that as I'd say some of the features are a bit out of date now but worth a look over, plus the gantry gets quite wide.

Boyan Silyavski
28-03-2017, 06:48 PM
Charlie,

Use 100x100x3 or 4mm box section, weld it and you dont need any diagonal bracing and similar. Just a simple table. Cheapest and strongest.

JAZZCNC
28-03-2017, 09:33 PM
Ok,will stop bragging, its obvious that i love my machine :beer:

Of course it couldn't have been able to happen without the help of others, Dean and Johnathan mainly.

No Don't stop Bragging you have every right you've made an excellent machine so should be very proud. I was wrong in how I worded it and wasn't my intention to pull your machine down so please don't take that way.
My point was mostly that your Design isn't anything special or unique that hasn't been done before, only so many ways to build these things.!! . . . Yes it's got few bits which aren't the norm and some parts are way overly engineered (which IMO is wasteful. Excess Over engineering just costs money and lowers performance) . . But in general the format is the same as many others which is mostly what I meant to get over to Charlie.



Charlie:

Just bite the bullet mate and build it strong from the get-go.! . . Strong machine will cut ply, maybe not at ideal feeds but will do it without blinking. Weak machine will just wreck aluminium every time.:thumbdown:

charlieuk
28-03-2017, 10:18 PM
what is your definition of strong dean? steel with servos???? like the vertical machine you posted a picture of ???

which design would be better to go for if built strong??

I will happily build it however just not sure at the moment at what level it needs to be at.

many thanks

JAZZCNC
28-03-2017, 11:26 PM
what is your definition of strong dean? steel with servos???? like the vertical machine you posted a picture of ???

which design would be better to go for if built strong??

I will happily build it however just not sure at the moment at what level it needs to be at.

many thanks

The materials it's built from are important but far more important is the design. The vertical machine I've shown isn't design I'd suggest for high quality cutting of Aluminium. It's designed for cutting woods and sign material which it is more than strong enough to do without being over built as to rob it of acceleration/speed.

The problem you have is that to cut woods correctly requires higher feed rates. To produce high quality finish in aluminium required for moulds requires very ridged design and this by it's nature means having to be built from dense often heavy materials. It also needs certain amount of speed/acceleration for 3D surfaces moulds use. This weight conflicts with high feeds unless the rest of the components match up and this unfortunatly means taking the servo route and everything that goes with it.

This dilemma then gets componded by size. Small/Med machines are managable but when you get into 8x4 or even 4x4 it up's the game to another level.
If you want high quality finish in aluminium then you really really need to look long hard at design and what components your going to put with it. Any weak area will be magnified when it comes to surface finish in aluminium.

charlieuk
28-03-2017, 11:58 PM
ok so sounding like the thing to do for now is to scrap the idea of being able to feed a full sheet of ply through and just focus on the aluminium thing and try and make it as compact as possible while keeping a 650 x 1270 table area Then to dream about a 3rd 8 x 4 machine in the distant future.

Any pictures of a 'strong' 600 x 900 size machine I should be using for inspiration?

Boyan Silyavski
29-03-2017, 04:00 PM
Any pictures of a 'strong' 600 x 900 size machine I should be using for inspiration?

My first build from signature, that i did for a friend. Free plans in Sketchup are somewhere in the build. if you are not happy with gantry you could do that from alulminum L shaped or box shaped, though i dont see a reason. that machine is 400x1000x180 but you can widen it without changing anything. all else stay same. It can support up to 5-7kw spindle without any problem. but put a 2.2kw or 3kw spindle there and you have it.


I dont know what exactly you are looking at, Charlie? Why the indecision? The above said is easy to do and i could send you the plans for free if you dont find them in the thread. I could send you for free also the plans of my second machine, but you have to shorten it yourself for half sheet and figure how to put it together, cause i simply dont have a time to support that plans on every step of the way. Each of them will result in a machine that is tested, proven and without any weak spots

As Dean said my designs could not be the greatest innovations, but both machines a build, tested and have no faults.


PS. I have not cut aluminum lately but here is a short video i made once. 6mm bit, full depth i believe at ~2000mm/min. Perfect cut and perfect mirror like finish, though can not be well seen on video. listen to the sound of the machine, then go youtube and compare. Did i say Z fully extended...


https://youtu.be/XXR3396MAvg

charlieuk
08-05-2017, 10:55 AM
Right well I have finally moved back to the uk, I thought it was best to wait until I was back so I could have a bit of time to re asses, think and deside what I had room for and also take a look at the steel that I was given. It is 100x100 x5mm wall so a little heavier than what people have said so hope that is ok and I have nearly 20m in total so should be plenty there although was thinking of making the legs of something a little lighter weigh?

I have decided on a work area that will allow a max 1220 x 600 to be cut but with the focus on aluminium and forget full sheets for the moment.

I don't really want to do the hole epoxy level thing so will need to figure the best place to build the adjustment in to the axis's

If it is easier and up for the job I will use aluminium extrushion for the gantry.

So back to the drawing board and to start planing how to do the frame.

Neale
08-05-2017, 02:33 PM
I have decided on a work area that will allow a max 1220 x 600 to be cut but with the focus on aluminium and forget full sheets for the moment.

I don't really want to do the hole epoxy level thing so will need to figure the best place to build the adjustment in to the axis's

My machine uses 100x50x3 steel box for the long X rails supports, giving around 1550mm travel so not that different to your plan. I also added steel strip inside to give me something to drill and tap for rail hold-down bolts, which is why I could manage with 3mm. However, my rails dip around 1.5mm in the centre. I don't know if the steel was bent to start with, or if it's welding distortion, or something else. The moral is, though, that unless you can really measure and control the materials and the build methods, you have to allow some way to correct the inevitable errors that creep in. I ended up using a mixture of epoxy and shimming, but I'm not saying that that's the best method, just one that worked in this case. Good luck with the build, and don't take anything (like steel box section being straight!) for granted...

charlieuk
08-05-2017, 05:03 PM
once I have selected the best lengths to use my plan was depending how much they are out to get two of the faces machined flat or if to far out weld a strip to the top and get that machined instead.

I'm thinking doing the same raised rail design but then have flat plates on the verticals to bolt the long rails to so I can shim them or what ever is needed.

charlieuk
08-05-2017, 11:17 PM
Quick question.. If I build a square frame for the bed is it better to cut the corners at 45deg and then weld them like that or just butt joint them. I'm thinking if I do it at 45 there less likely to distort and I will get a tighter joint. I will be tig welding rather than mig.

Nickhofen
09-05-2017, 05:15 AM
https://youtu.be/XXR3396MAvg[/QUOTE]

That video, showing the machine cutting aluminum like that is very impressive I must say!

charlieuk
10-05-2017, 10:20 AM
just trying to get the basics down see what you think.

the frame is the 100 x 100 x 5 steel tube i was given

I have the two top rails mounted on plates on top of the short verticals to allow for shimming. I will see get the top rails machined flat before so and maybe one with a straight edge down it for the linear rail to butt up to.

I need to obviously put some diagonals in somewhere I guess

at the moment I have the 3 cross members at 50 x 50 x 4mm with 330mm centers ?

charlieuk
11-05-2017, 12:07 AM
I did a little more adding the rail detail and some diagonals.


I keep reading about everyone using the aluminium L style gantry, is this only suitable for wood cutting? would I be better off with a steel arrangement for cutting aluminium?

charlieuk
11-05-2017, 11:11 AM
I have put a gantry together using 45 x 90 kjn extrusion as I think dean said you can bolt bk blocks and bearing straight to it I have it sitting on 20mm plates on the carriages and 20mm end plates.

I have only put the drawing together to get a bit of a idea if I'm going in the right direction, dimensions may need to be altered.

Any one got any comments on this? does it need to be beefed up or made in steel to get high quality cuts on alli?

charlieuk
12-05-2017, 10:05 PM
Does any one have any comments on what I have done so far?

Can any one offer any advice on what ball screws to go for for the x y and z axis?
was thinking of running two screws on the X linked by belts

many thanks

1Jumper10
13-05-2017, 01:42 AM
It looks like a solid design to me. I dont think you'll have any problems with your frame not being rigid enough. I think twin ballscrews, one each side is a better design than one down the middle. They're easy enough to synchronize either with belts or just dual motors. But, I've never built a machine with ballscrews so judge my comments accordingly. Its very possible I may be totally wrong :)

Boyan Silyavski
13-05-2017, 08:12 AM
Does any one have any comments on what I have done so far?

Can any one offer any advice on what ball screws to go for for the x y and z axis?
was thinking of running two screws on the X linked by belts

many thanks

When you are in front of the machine X is left right, Y and A are the long axis. Its called "the right hand rule"

21617


So on your question, i will always prefer 2 motors each belt driving via reduction or not the separate ball screws, versus 1 motor belt driving both ball screws at once. While second is a fool proof way to do it, its more difficult to set up, dust protection will be needed for the belt, motor and drive have to be more carefully matched to the machine. Plus tension to the belt must be right to function properly and there is more possibility for misalignment. In other words i choose the simpler way to do things. So at the end of the day= there is no better way. its all the same if done right. The result i mean.

PS. Also comes to my mind that the one motor design could not be 100% suitable for very fast and heavy machines say 20-30 meters per minute and serious acceleration. Not that there are such in the majority of the DIY builds. Its one thing to put much pressure on 300 mm belt and another on 3 meter belt

charlieuk
13-05-2017, 09:19 AM
how is the CSMIO/IP-M now with dual motors? I know there was talk about it a few years ago

Neale
13-05-2017, 11:49 AM
how is the CSMIO/IP-M now with dual motors? I know there was talk about it a few years ago

I was one of the people asking about it, because I was trying to decide whether to go one big motor/long belt or two motors, one per ballscrew. In the end, I went the two-motor route with an IP/M. There are probably two issues - initial homing and keeping sync when running. Second point first - I have had no problems with the two motors staying in sync when all is running well. I set up the IP/M as per the manual and it does what it says on the tin. I use EM806 digital drivers with stall detect and they trip if one motors stalls (which has generally been when I've been pushing the machine a bit). Fault signal goes to safety relay which signals IP/M and everything stops with no damage.

Now - homing. I spent some time initially squaring the gantry, using the "four pins in a square and measure diagonals" method. I have inductive proximity switches as home switches on both ends of gantry; one is wired to the IP/M and the other is not. Well, it is really but not configured in Mach3. When machine is first switched on, I home all axes as usual (configured so X and Y home simultaneously to save time). I then hit estop which cuts power to motors. I tweak the slave axis pulley by hand, simulating the Mach3 homing process and watching the led indicator on the switch. That is, I wind the screw until the light goes out, then slowly wind it the other way until it relights. Reset estop, re-home just to make sure (only takes a second or two) and I'm set to go for the rest of that session. Unless estop is triggered for some reason I never go through the manual process again for the rest of that session; on the odd occasion when I've checked it's been bang on. Generally it's close enough even after shutting down and restarting later. Because of the motor cogging effect, I'm probably no better than the nearest full step doing this. So, that's to within 0.025mm at the end of a 1000mm gantry. Probably good enough for a machine used primarily for wood.

I've thought about adding a little bit of complexity which would do a proper master/slave homing job. With a lesser motion controller with the usual 5V single-ended signalling this would be easy but the IP/M lets me use differential connections to the drivers and 24V signalling which complicates putting an extra bit of electronics between the two. On balance, I would rather keep differential signalling and the manual homing. And yes, I know it's not that difficult to put the electronics together, but it's more effort than just sticking an Arduino board in there. Or I could have spent nearly three times as much for an IP/S...

charlieuk
13-05-2017, 12:01 PM
cool thanks for that, so if you were to do it again what would you go for?

Neale
13-05-2017, 01:00 PM
Good question. Just for context, mine is a floor-standing, all-welded-steel, construction. Mostly 50x50x3 but X rails are carried on 100x50x3. Cutting area approx 1750x750 (quarter-sheet with a bit to spare). 20mm Hiwin rails all round, 2005 ballscrews for X, 1605 for Y and Z.

IP/M, EM806, Pilz safety relay (new-but-obsolete model from eBay for 25), HuanYang VFD - all work fine. IP/M, once I had fixed the correct firmware version and "upgraded" Mach3 to a slightly earlier version, all work fine and support my touchplates (one movable, one set in bed) for zeroing and a couple of macros adapted from elsewhere for initial tool-setting and tool-change. Nothing there I really want to change, although I could wish that IP/M included that extra little bit of firmware from the IP/S to do proper master/slave homing. I even looked at putting a custom Mach3 config together to trick the IP/M into homing X and A separately-but-together (a bit like simultaneous X and Y homing, which works fine). Mach3 was easily confused into doing this, but it seems that you can only have one IP/M configuration on the machine and it didn't want to play.

Things I would do differently (and might still do so, one day):

Use better pitch ballscrews. I bought the hardware a couple of years back, at least, so I had exact dimensions to build to. I didn't want to go to China for that (although I would do so now) and my lathe would not take that size ballscrew to do my own machining (although my latest lathe will). So I bought what was available off-the-shelf at the best price from CNC4YOU (as I had good experience with them) and that meant 2005/1605. No 2010/1610 available. 2005 with my ballscrew length gives a theoretical critical speed of around 1000RPM (give or take a bit) which gives 5m/min. 1000RPM is also about the corner speed of my NEMA 23/3Nm steppers, so with 1-1 belt drive, this was a good match. In practice, I've had to drop to 4.5m/min on X because I get the odd stall on rapid otherwise. The gantry is pretty heavy (all-steel) although theoretically it should be OK. If I were doing it again, I would go for 2010, probably, with a change of pulley ratio and aim at nearer, maybe, 9m/min. The original design speed seemed like magic after my old MDF-built machine with its max 900mm/min, but it's less than optimum by a long way. Works fine, but could work better.

I have a love-hate relationship with my inductive proximity switches. I am using cheap-from-China items, around 12 for 4 kind of level, and they have one big annoying feature. There is virtually no hysteresis between switch-on and switch-off points. So on homing, gantry moves towards switch, switch trips, gantry reverses until switch untrips, and that's home. Mach3 now sets switch as limit not home switch. Any subsequent machine vibration can move the trigger just enough to operate the switch - "Panic! Limit switch trip!" says Mach3 and does an e-stop. This happens a lot on Z and gave me no end of trouble until Dean pointed out that you can configure the IP/M to move the axis a tiny amount away from the switch once it has homed and set zero there. This fixes the problem in practice, but it still annoys me that I have to do this!

One thing I did get more-or-less right was to include all the bits and pieces that I thought that I would want before I started using the machine. So, home and limit switches fitted (each axis to IP/M separately for simultaneous homing) although home and limit switches wired in series per axis. Works fine. Touchplate connections provided. VFD start/stop and analogue speed control from day 1. Two-speed water pump - nominal 12V pump that gets 12V for initial priming but then gets switched to 5V for long-period running - the spindle doesn't need a lot of cooling and I often don't use it at all for quick jobs. It's too easy just to "test it to make sure it works" without, say, full limit switches, and then you hit the wrong arrow in your haste and the gantry tries to run off the end of its rails. I've done this, and was really grateful that limit switches were there to save me. I'm also using industrial-style switchgear from ElectricCenter (branches everywhere and they were keen to give me "trade discount") which is much more solid and suited to the environment than, say, the stuff that comes from Maplin with the same nominal rating but rather less built-like-a-brick-outhouse feel. Worth the extra few quid at the outset, along with a ferrule-crimping tool that means that every wire is terminated with a ferrule. You wouldn't believe how much easier this makes inserting wires into terminal blocks in awkward places, and removes almost all possibility of stray strands causing impossible-to-find shorts.

Today, I might consider using the UC300ETH (I would always go ethernet rather than USB, and forget parallel port altogether) in place of the IP/M. Similar capabilities on paper, but I have to say that I like the feel of the bullet-proof, 24V, IP/M.

charlieuk
13-05-2017, 02:46 PM
that's interesting sounds like your machine is similar to what I want to build size wise and you had similar problems to my first machine using cheap sensors which I also use a ip/m on. sound like I will stick with the ip/m then and go slaved unless there is any reason not to I want to stick with similar component to my first machine so I'm not having to learn lots of new stuff slave on the ip/m would be great.

two things I realy need to sort out for my old machine and the new one will be a touch plate and some sort of pendant but when I saw the cost of the one on cs labs it scared me a bit!

Neale
13-05-2017, 03:02 PM
I'm using a Logitech wireless keyboard with built-in touchpad at the moment. Haven't had any problems with that (a lot of people say that you shouldn't use wireless keyboards as they aren't too reliable in a noisy environment) but a wireless MPG would be good. I keep looking at the Chinese wireless units for around 100 which would make zero-setting while leaning over the machine much easier. Still, finishing the swivelling monitor bracket so I can actually see the monitor properly while zero-setting would be a good step in the right direction...

charlieuk
13-05-2017, 05:20 PM
I'm using a Logitech wireless keyboard with built-in touchpad at the moment. Haven't had any problems with that (a lot of people say that you shouldn't use wireless keyboards as they aren't too reliable in a noisy environment) but a wireless MPG would be good. I keep looking at the Chinese wireless units for around 100 which would make zero-setting while leaning over the machine much easier. Still, finishing the swivelling monitor bracket so I can actually see the monitor properly while zero-setting would be a good step in the right direction...

I'm not to fussed about the wireless thing, I can almost reach the keyboard from the machine but would make life a lot nicer if I could just have something to jog it around easily. do the one's that state mach3 just plug straight in to the pc? or do they go into the csmio ?

Neale
13-05-2017, 05:47 PM
The Mach3 ones talk to Mach3 via the PC and some kind of USB wireless dongle. They don't connect to the IP/M. The wireless versions look like updated versions of the wired (USB) versions that have been around for a while.

charlieuk
13-05-2017, 11:03 PM
cool ill have to look in to those a bit more.

so moving on for my goal of cutting alli is 2005 ball screws for the two on the x and 1605 for y and z the right ones to go for?

Any idea on the ali gantry, I know jazz uses them a lot on his but not sure if they are all designed for the same purpose? it would certainly make my life easier if I didn't need to use steel.

Neale
14-05-2017, 12:40 AM
5mm pitch is a bit low for cutting wood but plenty for cutting aluminium, or at least this is true on my machine. However, I've only just started trying to cut aluminium so haven't much experience of this yet. On balance, as I said earlier, I probably should have gone for 10mm pitch but as I do a lot of small work and 3D machining, it's acceleration more than absolute speed that improves job time so in practice it's not that much of a problem - for me. There's a bunch of engineering trade-offs in there and you have to decide for yourself where the priorities are.

I have no experience of aluminium gantries. I've gone from MDF to welded steel, so can't make any intelligent comments about aluminium but there are plenty of people out there who do use aluminium (my feeling is that this is the most popular material by far for gantries) and there are plenty of build logs and other comments about it. In practice I don't think that the weight difference is particularly important (which is not intuitive, but then neither is the fact that the rotational inertia of the ballscrews is a major factor in limiting gantry acceleration) so it's down to material availability/price and facilities available for machining and assembly that will probably drive the decision. I have a MIG welder and milling machine, which was a major factor in my choice. YMMV...

charlieuk
23-05-2017, 11:56 PM
I'm trying to decide how is best to do the stepper mounts to include a belt drive to each of the ball screws.

I was going to have them on the side but that will increase the over all width a fair bit

I was all so wondering if there is a way I could have the motors inside the main tube but not sure its a great idea.

any one have any ideas or suggestions ?

21756

21757

routercnc
24-05-2017, 01:26 PM
I'm trying to decide how is best to do the stepper mounts to include a belt drive to each of the ball screws.

I was going to have them on the side but that will increase the over all width a fair bit

I was all so wondering if there is a way I could have the motors inside the main tube but not sure its a great idea.

any one have any ideas or suggestions ?

21756

21757

Structurally/mechanically ok but need to get cables to the motors plus best to put holes in the mounting plate and maybe box section as well to allow for cooling.

charlieuk
24-05-2017, 11:55 PM
yes, I was thinking I would probably have the mounting plate welded on the end and then have a hole in the side to post the motor in and allow it to be mounted up, just hoping there will be enough room to get the pullys on doing it like this.

the other think I'm just trying to think about is mounting the ball screw blocks, and having a method to adjust them a little if needed so rather than mounting them direct to the steel have a plate in-between them with some elongated mounting slots?

Clive S
25-05-2017, 12:11 AM
yes, I was thinking I would probably have the mounting plate welded on the end and then have a hole in the side to post the motor in and allow it to be mounted up, just hoping there will be enough room to get the pullys on doing it like this. I don't think it will be a good idea to weld a plate on the end.
How about making a motor mount with the appropriate centre hole and elongated slots made out of ali and make it wrap around the box on the outside left and bottom edge. That way the motor can be fitted to the mount and then slid into the box and bolted through the flanges of the mount into the steel box section.

charlieuk
25-05-2017, 09:37 AM
do you mind explaining why not?

this is what I had in mind, could easily add extra cooling around it and then would print some cover with mesh in to prevent crap going in.

Clive S
25-05-2017, 09:51 AM
do you mind explaining why not?

this is what I had in mind, could easily add extra cooling around it and then would print some cover with mesh in to prevent crap going in.

Ok that looks fine if you can wiggle the motor in there I would think you will have to mill out the steel plate so that the motor would be inlet into it because the motor shafts are generally not long enough for the pulley.

charlieuk
25-05-2017, 10:29 AM
yes I have that recess drawn in there it should be fine getting it in and then will just tap the holes on the motor



like I mentioned I'm a bit worried about getting the bk blocks all lined up so thinking maybe make some plates up like in the pic just to allow 1.5mm ether way incase the holes are not perfect. but now just thinking maybe I would be better making a bracket from angle ali and using a fk support instead?

routercnc
25-05-2017, 01:45 PM
. . . like I mentioned I'm a bit worried about getting the bk blocks all lined up so thinking maybe make some plates up like in the pic just to allow 1.5mm ether way incase the holes are not perfect. but now just thinking maybe I would be better making a bracket from angle ali and using a fk support instead?

If you want to go the route you have drawn then you can make the mounting plate into a tramming plate. Add a cup-point grub screw to each corner which contacts the RHS underneath and allows fine tuning in/out and various angles. When aligned the bolts are tightened down holding the plate in this position. Be aware you are relying on the stiffness of the cup point area contact with the RHS to give the stiffness of the axis as seen by the machine, but if this worries you once it is set up you can remove the plate, cover the underside with machine epoxy and tighten back down. It will set with the alignment position you dialled in using the grub screws.

See here post #23. Grub screws around edge of bracket give alignment, then main bolts tighten against them:
http://www.mycncuk.com/threads/9141-Lathe-suggestions/page2

Clive S
25-05-2017, 04:48 PM
yes I have that recess drawn in there it should be fine getting it in and then will just tap the holes on the motor
I see the recess from the outside but it is usual to recess from the inside so that the motor sticks out more.

Are you sure the the motor and shaft with the pulley on will stick out enough?

charlieuk
25-05-2017, 05:11 PM
thanks for spotting that i realised i hadn't modified the front for the motor to slide the rear is like this. I have left 5mm thickness. I like the idea of using grubs I was going to do something similar for the gantry but sounds like a good idea to do it all round and then like you say just bed everything with epoxy after that way you don't have to do all that sell leveling resin stuff. :)

I keep hearing dean say adjustment adjustment adjustment which I think is exactly right for diy stuff

all fixed will see if I can find some pullies to put on there but its the same as what I did on my other machine essentially so should be fine.

charlieuk
26-05-2017, 10:16 AM
so thinking this for the screw support instead, at the moment I have the bracket at 15mm alli, not sure if that's ok or if it would need to be bigger, tbh I haven't looked to see what section is even available.21779

Clive S
26-05-2017, 11:04 AM
I have left 5mm thickness. Personally I would cut that down to 3 mm to get the motor shaft sticking out more.

charlieuk
26-05-2017, 07:07 PM
found some pulllys on line so had a play 5mm is just doable, going down to 4 would be plenty so will do that. even at 5 mm the pullly would go all the way on its just a bit harder to do the grub screw up.

hmm now on to the y and z not looking forward to trying to draw this!

charlieuk
27-05-2017, 01:49 AM
so just kinda throwing something together if anyone has any thoughts let me know I'm not really to sure what I'm doing.

charlieuk
27-05-2017, 11:07 AM
getting a bit obsed with trying to get this designed and built asap so was up until 2am last night searching the forum and looking for ideas, I keep ending up looking at zeeflyboys thread and drawings as it looks so nice.

I'm still trying to rough out the design and get a feel for what I'm doing



what I'm wondering at the moment is how fare do the hiwin carriages need to be spaced apart, what's a acceptable distance?





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charlieuk
30-05-2017, 11:08 PM
I steel I have that I'm going to use for the machine has a bit of surface rust from sitting out for the last two years so wanted to try the viniger trick to clean it up. I didn't have any white viniger to hand but did have a bottle of brick cleaner acid so gave that a try and can't believe how well it works! One the design is complete I will cut all the bits to length the pop it all in a tank to soak :)

Nickhofen
31-05-2017, 01:00 PM
After the vinegar bath you can spray WD40 at the inner side since you are going to paint the steel from outside, the rust I see is not that much that is going to cause trouble but it is always good to take precautions.

charlieuk
31-05-2017, 11:49 PM
i think your supposed to do a alkaline solution after the vinegar or acid to neutralise it and then yes i should probably get something to put on the inside. I will see if i can spray some red oxide in there and if not go for the machine oil option or similar.