Centroid Community CNC Support Forum

hello ive been doing alot of fine tuning lately and have gotten my x,y and backlash in my opinion completely eliminated with tolerances .0005 and backlash so small i cant measure it. after moving on to making perfect circles though i noticed there is a light difference in the 10:30 and 4:30 where its slightly oval. small enough i cant measure it but when i put a set pin in the hole it wabbles those directions slightly. ive done the basic research and doesnt seam to be mechanical and came across other post with people using other software that had motor settings within the app that were different in the x and y causing a difference when moving at the same time. not sure if acorn has smoothing settings like this per motor but would like to know if anyone has an idea as to what i can look for.

btw this is for acorn milling software with closed loop steppers.

Please post a fresh report.zip from the machine:

hi this is one from a fresh boot not sure if it matters.

Backlash on y is way too much to make round holes, must be fixed mechanically

I also doubt that the pitch on Y is ok, I never had that much deviation from the default value.

Uwe

I agree, .0068 backlash is HUGE. This is a mechanical issues that needs fixed first.

suntravel wrote: ↑Fri Apr 11, 2025 1:45 pm

Code: Select all

Axis  Label  Motor                Encoder      Lash Comp.        Limit          Home      Dir  Screw
             revs/in              counts/rev.  (inches)          -     +        -     +   Rev  Comp
1     X      5.0804411060000003      4000        0.0029          0     0        0     1   Y     N
2     Y      5.0912161339999997      4000        0.0068          0     0        0     1   Y     N
3     Z      5.0834597180000003      4000        0.0014          0     0        0     1   Y     N

Backlash on y is way too much to make round holes, must be fixed mechanically

I also doubt that the pitch on Y is ok, I never had that much deviation from the default value.

Uwe

yea i think this is just an issue with the kit i got from Arizona cnc. i have talked to him multiple times about this issue and altered machine for better fitment of the y but i think its just something wrong with the y kit i received but outside of getting told everything is perfect and tested ive not been able to resolve the issue with y. but these are the settings needed to make a perfect square. ive had this kit now for the better part of 6-7 months and have spent a good 3-4 trying to track down the y issue and nothing gets it closer than that.

anyone know what i could look for with the y axis, there is literally nothing that an be adjusted. it has 2 bearing that sit on either side of the motor mount, then a screw on coupler with a set screw then motor mounts on. in the middle is just a block with 2 screws holding the y axis. other than maybe the ball bearing holders being bad i dont see a way to adjust it any more. only option is to tighten the coupler but that doesn't change the runout. i have just finished taking it all apart and back together again haha.

Here some pics

If you can see either end of the Y axis ballscrew I'd put a dial indicator against it and jog the machine backwards and forwards and see if there is any play there. Also check the bolts for the ballscrew unit attached to the underside of the machine bed are actually tight, I've seen them loose before.