New build with recycled parts on a ridiculous budget 120cm*60cm work area

[Desertboy]

Holy crap batman!
Im hoping I will be satisfied with 5m/m.
It sounds fast.. dont know how fast it will feel like though ;)

Skickat från min SM-G955F via Tapatalk

It seems fast when you first move it that speed but wait till your cutting lol it's just never fast enough



A quick mockup of the Bk15 mount this will space the 2010 ballscrew to align with the existing nema 23 mount for bk12 if I fit it upside down and it will leave 3mm clearance (Instead of 6mm) for the DSG20.

Bought another 10 omron microswitches as well so going to be properly prepared with 14 roller switches lol.

[Nickhofen]

You might like that.
It is a diy handheld MPG to linuxcnc a guy from Denmark post at a cnc group on Facebook. The group is the DIY CNC and the member, Allan Madsen, said that today he is going to provide a link, to where he will post the files, to make it work in linuxcnc.

[Desertboy]

Excellent work by Allan will have to check it out, I know people have also got PS3 and Xbox controllers working in Linuxcnc for controlling the machines ;)

Having some latency issues with the I7 not geting the performance I should, it could be a few things from what I read up.

But the main candidates seem to be Nvidia GFX card (Need to work out how to turn it off in Linux so I can use the on board, machine is dual boot with windows want the Nvidia card for Fusion.) Possibly SMI, disabling cores and a couple of other things.

Toying with swapping the Y axis nema mounts so it's belt driven 1:2 motor:ballscrew as the 1604's have a critical speed over 2000rpm so I'm hoping I can drive the nema's at 1000rpm and get 8m/min out the screws and drive the 2010 at 1000rpm direct drive so I get 10m/min on the gantry. Resolution will be halved doing this but then the resolution of the 2010 ballscrew is still less.

Using 2010 ballscrew will give positional accuracy of ~0.05mm, slightly better with the 1604 geared 1:2 (Which essentially becomes an 8mm pitch for accuracy purposes) the microswitches I'm using (Omron) have a repeatability between 30-50 microns almost the same as the cheapo inductive sensors most of us use which works out to 0.05mm. So my repeatability on any part is limited to ths it might be better of course but in theory it should never be worse. (Ignoring wear and tear)

I have some 40mm inductive sensors I recovered that run on 48v I got from a large printer I scrapped I suspect these have high accuracy over larger distances, when I googled them they were over £100 a sensor the main reason I kept them lol.

I might have to strengthen the gantry with angle steel ground flat both sides and cnc the holes to bolt in into the T slot so the machine is rigid enough to actually take advantage of the speeds and can my PC generate enough pulses for that speed. I can see a step generator in my near future lol. I'm glad I have a friend who works for a big cnc firm as a foreman and who's job for the first 10 years was grinding ;) He also told me they been binning Hiwin's so he going to see if he can get me a set before they go in the skip, he laughed at my 15mm Hiwin's lol.

Thinking when I upgrade or build new if I don't go servos then going nema 24

https://www.ebay.co.uk/itm/Nema-24-S...item1c54c443d4

Good price for 8 wire motor, 4nm

Had a few crazy ideas for upgrading including 2* 2m travel gantries ;)

Still not got dual homing sorted but I did get an engineers square to straighten the gantry (It was well out, which is the technical and scientific term) and was happy to see when I straightened one side and checked the other side it was perfect. I had the machine switched off and rotated one ballscrew by hand.

Recessing the extrusion into the plate really helps in squaring the gantry you can feel it click into place when you've got it right.

[Desertboy]

I have a 1204 ballscrew, it's a ground THK C3 with matching bearings 450mm long.

I paid £150 for it a few years ago from South Korea, I was wondering what it's good for? I was wondering if I could use it for a Z axis? It would have another advantage that it will mount easier with 15mm Hiwin's but I worry it's not strong enough.

Still floating ideas
https://forum.linuxcnc.org/38-genera...ared-work-area

This one's a doozy ;) I think linuxcnc is probably capable of driving something like this especially now everything is joints but CAM software could be a bigger issue.



I just cloned the gantry not a proper design yet just floating ideas

[Nr1madman]

I dream about the day I get to have these problems :D
This is just a guess but have you tried a downcut bit? As you are not cutting straight through it should leave a good finish on the topside?

[Nickhofen]

As Robert said ,down cut bit, slower feed and............ put self adhesive tape at the side you cut, after the cut remove it and you will have a cleaner cut.

[Desertboy]

As Robert said ,down cut bit, slower feed and............ put self adhesive tape at the side you cut, after the cut remove it and you will have a cleaner cut.

Good advice this was very old oak I tried a newer bit today didn't tear the same but still not perfect.

Just bit the bullet and bought a hardware step generator a Mesa 5i25 as my pc's not giving me the performance I can get out the machine.

https://www.ebay.co.uk/itm/272930377353

Plugs into the breakout board so no need to rewire which is good ;) I was in Vilnius last year I could have collected it lol.

This will generate more pulses than I could ever need it expands the BOB connectivity considerably but it's the pulses I can about, it can be linked to encoders for other funky stuff.

[Clive S]

Plugs into the breakout board so no need to rewire which is good ;)

What do you mean by this? This will plug into your PC PCI slot but then you will need a bob like a 7i76 if you just use a standard BOB you will still only have 5 inputs and the opto's will no doubt be slow.

[Desertboy]

What do you mean by this? This will plug into your PC PCI slot but then you will need a bob like a 7i76 if you just use a standard BOB you will still only have 5 inputs and the opto's will no doubt be slow.

https://forum.linuxcnc.org/38-genera...nerator#106403

Just remember most cheap parallel port breakout boards are not designed to be able to handle the speed potential of hardware step generation. They often have relatively slow optos, not a problem with a slow parallel port, and shouldn't be with an ordinary step motor config (unless your using really high micro stepping and spinning fast). But it can be a problem with high resolution step/dir servos.

So we shall see I guess I'm only using 8 (maybe 16) microsteps with nema's. Not worried about the other inputs at moment but at some point I will get a daughter board for it and if I find speed is an issue that will be sooner than later lol. I assume I can set the khz within a certain range for each axis? If I can run at 50khz per axis I'll be more than happy for now.

Am I doing my maths correct?
8*200 steps *20 (revolutions in 1m) * 2 pulses per step=64000 pulses/metre
I want 10/min it would be 64000*10=640000khz then divide by 60 == 10666.66 khz per axis

Good thing about mesa is their upgradability.

[Clive S]

This will generate more pulses than I could ever need it expands the BOB connectivity considerably but it's the pulses I can about, it can be linked to encoders for other funky stuff.

I do read all your post on the other forum as well. But you will need more inputs if you are using encoders and dual homing etc. The beauty of the 7i76 is that you will have differentials output for the step gens and 24v inputs etc.