[Cret]

Update - I think I may have resolved this fault, at least temporarily. I've just moved some wires around in the box a bit, to try and put a little space between the power feed from the PSUs to the drivers, and the signal wires to the drivers. They're only an inch or two apart but previously they were more or less sitting on each other.

So I plugged it all in again, and it's working perfectly. Ran it for a few minutes back & forth a lot on each axis, and no problems at all.
Every other time I've run it with everything in the PC case there's been an intermittent but quick to appear fault.

Not conclusive, but the one time it's worked perfectly is just after I've moved wires away from each other - don't think it's coincidence.

So I will try to buy some single core shielded wire to replace the current signal wires, and route them a bit better.
Also I'm going to make a ply shield with some foil on it (in case it helps) to fit over the power feeds o see if this helps too.

So happy to have it almost ready to use though. I've wanted to do this for years!

[Cret]

Never mind - I believe I have it fixed now. I think it was interference between the power feeds to the drivers, and the signal lines to the drivers. I moved them apart slightly and it began working fine, so I've replaced the driver signal wires with some thicker shielded stuff I found, and it's behaving perfectly.

Next I need to fit the E stop. Do most people use end stops, or have no need because the machine 'knows' where it is once setup fully etc?

[Cret]

Well it's still behaving perfectly now. So far anyway....

So I've now calibrated the axes.
Was quite amazed that the X axis moves 0.01mm out over 20mm, so about 0.4 thou out over 20mm. I suppose that sounds good over a small distance like 20mm, but amplified across the length of the table I guess it's not so great. Not sure how to calibrate it over a longer distance without having DROs fitted to it, so for now I think this will have to suffice until I can afford to fit a set of them, unless there's any clever tricks for really accurately measuring/testing over a longer movement without them?

The motors are a little warm after it's been running maybe half and hour but I guess that's perfectly fine since they're holding position when not moving, providing they don't get actually hot?

[Cret]

Update - the steppers get to 40C max it seems, this has been constant for some time now but it's all been running for several hours. Doesn't seem unreasonable I don't think.

I have set up soft limits and a home point where the head is fully up at zero, and the X&Y are centred at zero.
The soft limits work ok, and the E Stop button I wired in works now too.

I loaded an example file and the code appears to move the machine around ok, although it keeps hitting the cautious soft limits I've set for now. That's fine though.
One thing I'm unsure of is when I change tools and the protrude to different lengths, do I have to adjust the z axis maximum soft limit each time to suit the lowest part of the tool in relation to the table? Or is there another setting I should be using in relation to this sort of question?

Absolutely itching to try it out for real with something, even if it's just sticking a pen in it and getting it to write something!