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BACKLASH COMP ENBLD - causes 2 axis to move in STEP JOG MODE

PostPosted: Sun Aug 04, 2019 2:09 pm
by SupraStoked
Hello all,

I have a Taig Desktop CNC that I run using a G540 drive hooked up to 381oz. steppers from Automation Technology Inc.
About a month ago I was able to finally calibrate my steps/rev of my motors using a dial indicator and the jog panel on my UCCNC 2017 screenset software.
Seeing as how my axis are all leadscrew, I enabled backlash compensation in order to minimize the effects of backlash as much as possible.
It worked great! However.. when going back to re-tune my steps/rev once I got my hands on a more precision dial indicator, I noticed something very odd.

When I am setting up my work coordinate system and switch my jog mode into the "STEP" mode with an increment of .001", my machine moves TWO axis instead of just the one I am selecting to move.. I tried it with other axis and no matter what it still moves 2 axis at once which makes my work coordinate shift unintentionally as the DRO's on the UCCNC window does not show the second axis moving at all (but it is - I can visually see my motor couplings moving).

Now, I think the issue has to do something with backlash compensation being enabled because if I disable backlash comp on all the axis, the mill acts exactly as you would think it would. If I turn it back on, same problem - no matter if I am clicking one of my arrow keys on my keyboard or clicking the digital arrow keys on the UCCNC jog panel - it still gives me this issue only when backlash comp is enabled.

Any ideas why this might be happening?

Thanks in advance!

Re: BACKLASH COMP ENBLD - causes 2 axis to move in STEP JOG

PostPosted: Sun Aug 04, 2019 8:58 pm
by cncdrive
Try to adjust the comp.acceleration parameter higher.

Re: BACKLASH COMP ENBLD - causes 2 axis to move in STEP JOG

PostPosted: Fri Aug 09, 2019 11:43 pm
by SupraStoked
I will try that but what percentage higher should I go if its already at 42 (fyi - I calibrated my motors for imperial units, not metric). Also, will this fix the issue with it triggering the other axes in STEP mode?

Re: BACKLASH COMP ENBLD - causes 2 axis to move in STEP JOG

PostPosted: Sat Aug 10, 2019 12:42 am
by SupraStoked
cncdrive wrote:Try to adjust the comp.acceleration parameter higher.


I tried this just now after figuring out my max speeds for each of my axis and I still have the same issue where each axis decides to move when I'm in Step mode for only one axis. However, only the DRO for the selected axis changes with every click.

Re: BACKLASH COMP ENBLD - causes 2 axis to move in STEP JOG

PostPosted: Sat Aug 10, 2019 4:53 am
by Robertspark
wiring issue

check you zero volt connection to your drives, sounds like one drive is feeding steps into the other drive
it is likely to be on the 5volt side to the drives.

don't just look at the wiring and wiggle it about, unscrew the the cables at the connectors remove the cable, check for corrosion / oxidation reinsert and retighten.

if you are using a common 0v check that connector too