Which kit???

[Doddy]

This would be better in a separate thread, however, I appreciate your frustration here.

If you can confirm my assumptions:-

So, in summary, 3-axis machine - a DIY conversion of a mill. 3 motors, driven by three stepper-drivers, driven by a KK01 BoB, which in turn is driven by, what we understand to be a legitimate UC100. Software : Mach3 and UCCNC with the same observed behaviour.

I don't recall what stepper drivers you are using, or your main stepper PSU.

Observered behaviour: Missing steps (to the point where an axis will halt completely) in a given direction. This impacts typically at any time one axis, but that axis can differ on different tests?

Can you confirm: When an axis freezes - can you jog another axis whilst frozen? (so, if holding cursor-up freezes on Y+/Y-... does pressing cursor-left/right allow X to move)? (my reasoning... under the failure condition, does this only affect one axis or are other axis not currently active/observed also affected)

How often does this problem present itself. Is this once-in a blue moon, or every time you go to the machine. Or somewhere in between?

Is there any other relationship you can describe - for example does the problem only occur if the spindle is running, or otherwise (this is feeding a question into system noise and shielding and grounding strategies).

Visually, according to CNC4YOU website - it looks as though (though not documented) there is a power LED top-right of the board - is that illuminated constantly in use (both in good and bad operation)?

That you are losing motion across different axis *tends* to agree with your analysis that its unlikely to be the individual stepper drivers, or even steppers. So if you're looking for a common-mode failure you'd be looking at the PC/Software, UC100, KK01 or Stepper PSU. Personally I'd rule out the software because you've tried both Mach3 and UCCNC with the same behaviour. I'm not 100% convinced, but close enough that I'd not investigate the PC at this time (although it's an easy test if you have a spare PC/laptop).

Now, under normal conditions your specific description of losing steps in one direction, but not the other, is really very interesting - because it should never happen. Forgive me if you understand this already, but the conventional step/direction interface which clearly does work (at least part of the time) requires that the "direction" signal is a binary "left" or "right", or whatever you chose to refer to. The "step" signal is a pulse that commands the move. So, whether you're traversing "left" or "right" - you're generating a pulse train on the step pin - if you lose the "direction" signal you simply risk moving in the wrong direction.

So, if I believe your observation, my initial thoughts are that your direction signal is interfering with your step signal. At this stage I'd be eyeballing the wiring around the KK01, making sure there are no strands bridging between terminals or debris on the board. If the UC100 was dismantle-able I'd be doing the same with that. That's the first check.

That conveniently ignored the observed behaviour that this can affect different axis. That's more challenging and less logical. At that stage I'd be really questioning whether the behaviour of the KK01 was what I expected, and - short of deducing it was U/S - I'd be examining if the power to the board is correct (trust me - there's no such thing as a digital world - everything is a balance of probability) - and it's possible that the board is semi-operating without power by scavenging through the signal lines. I've seen it happen, in fact there was an investigation on here that was sourced from a a similar-ish issue (the solution for that isn't relevant here!). So, as much as you say your KK01 is fed from USB - please check and re-check that you've configured the KK01 correctly for USB power - pins 1&2 on the header next tot the USB socket.

How confident are you at tinkering with electronics, and in particular Arduino etc - the is a great use for them to either inject a pulse-direction signal into the KK01 (isolating the UC100), or to monitor the pulse train from the UC100. 30 minutes of coding could get you significantly better understanding of the problem.

Sorry, more questions than answers at this time. Be methodical and we can get to an end-state here.

[Doddy]

... AND ANOTHER THING.....

Is it possible to decouple the motors from the axis screws?, just too completely isolate this to an electrical, rather than mechanical problem?

[dazp1976]

Further to above I resolved the licence issue with UCCNC managed to get running in that.
It shows the same issues , sometimes a motion will move , sometimes it wont .
Sometimes this one , then that, then the other .

If it happens on both platforms that suggests to me it is not the software which is the issue ,
I have changed both leads so they should not be the problem. Breakout is CNC4you, KK01 with 5 volt supply via usb.
I dont think it is the microstepper driver wiring cos the problem occurs on different motions, rather than any particular one.

So where do I go from here??????????

I would pull all the wiring and check the lot.
Then if it's broke fix it and reinstall. Should eliminate any possible wiring defect.

You could try another board too if you really wanted to. You can get one similar to the KK for less than £10.
Same as the one I have ran for 3 years (£5 at the time).
https://www.ebay.co.uk/itm/5-axis-CN...cAAOSwbP1aZvGa

[Doddy]

You could try another board too if you really wanted to. You can get one similar to the KK for less than £10.
Same as the one I have ran for 3 years (£5 at the time).
https://www.ebay.co.uk/itm/5-axis-CN...cAAOSwbP1aZvGa

Cautionary note to OP; linked BoB - if you're looking to replace the BoB, above linked item (which I also use, as do many of us) requires a separate 12-24VDC power supply - it supplies the Opto-isolators used for limit switches and e-stops. Also, for the 0-10V spindle supply, if required. This, independent from the 5V supply from the USB lead.

Just want to make sure that any decision you make is fully understood.

[dazp1976]

Cautionary note to OP; linked BoB - if you're looking to replace the BoB, above linked item (which I also use, as do many of us) requires a separate 12-24VDC power supply - it supplies the Opto-isolators used for limit switches and e-stops. Also, for the 0-10V spindle supply, if required. This, independent from the 5V supply from the USB lead.

Just want to make sure that any decision you make is fully understood.

If you disable all the limits, stop etc though in mach etc, it's a cheap way of just testing the axis movements without needing to have a 24v supply. Just to test the KK board axis movements themselves aren't a problem.
Just don't move them to their ends.

I've never been a fan of the KK board anyway tbf.
Having everything on the same 5 volts always seemed a bit iffy to me. Especially when it came to e stop, limits, relay etc.
Everything else I see has 5v and 24v to isolate the inputs and outputs from each other.

Now I've mentioned that, that is worth ruling out. I mean the board I linked uses the 5v for the outputs and a seperate 12-24v for the inputs. Thus isolating inputs and outputs from each other

I have no VFD type spindle drive but I also have no cable sheilding and I'm using 3 axis with proximity sensors on the limits and seen no problems thus far.

[John11668]

Consensus here seems to be wiring I think. I will check the USB/PSU Jumper,
I replaced KK with CP1-10 provide spindle control , but the latter packed in so went back to KK (may have overlooked the jumper at that stage.)

I think it is maybe worth a rewire anyway. I used 0.5 throughout and while I guess it is probably OK for the signal wiring I did wonder whether to beef it for the motor wiring ( PSU seems to be giving steady +42 V as far as you can tell on a digital Multimeter)
I dont think the couplings are the problem It seems to happen randomly on all axes

Looking at the table arrangement what settings would you guys choose for the driver currents?


?


I will go back over wiring and grounding of shielding, I will also put a seperate 5v to the board and then Come back .
If it is with good news then fine , If it is not good then maybe I should start a new thread as I think Doddy suggested .

[John11668]

PS for the price of that BoB it is worth having as a spare . I have just ordered one.
I do have a more basic one somewhere if I could find it

[cropwell]

John,

When I lost my licence file, Artsoft were incredibly helpful and quickly sent me a copy. If you have a fully legal licence and have registered with Artsoft, you should be good.

Rob

[dazp1976]

PS for the price of that BoB it is worth having as a spare . I have just ordered one.
I do have a more basic one somewhere if I could find it

I think I've got 3 stashed

[John11668]

Right so BoB wont go amiss. Sounds like you are pessimistic about them Daz

So am reporting back with some better news . While I was jogging back and forth looking for a pattern I just happened to spot that when a jog failed , the red power light on he KK01 went out so on a failing jog the board power seemed to be dropping out.

I rigged a seperate power supply from a 5v PSU and moved the Jumper , and Hey presto , the problem seems to have gone away.
Deep sighs of relief followed .

I will still go though the wiring and upgrade the motor cables , also see that the screening is well grounded .

Maybe get some work done now

Thanks to all of you . This has been bugging me for days . I cant tell you how relieved I am