[killrmodz]

Good day everyone!

I need help trying to identify where the issue is in what i'm going to describe.

Background:
I just upgraded my current homebrew machine that is built with AVIDCNC parts. Replaced the steppers with clearpath servos SDSK models and went from VConn wheels to HGR20 Guides and Rails.

My issue:
After assuring all mechanical parts are square, tuning the clearpaths and updating MACH3 motor tuning with proper steps per, i ran some test cuts.

Linear cuts are fine in both X and Y axis directions. But when I cut arcs/circles, they are not concentric. Regardless of feedrates.

Attached will show you examples of the issues between 12 10 and 3 mm circles.

I've retuned the servos and double checked my settings in MACH3 and all look good.

I played with backlash compensation and didn't get much benefit.

I'm at a loss.

Thoughts?

Thanks!

[routalot]

Did you manage to cut those parts with the same machine and settings before the change of hardware?If the answer is negative then posting a few image files of the machine would be helpful as there may be factors originating from the height at which the Z axis is operating to the direction of cut.Posting speeds,feeds and depth of cut would be helpful,together with telling us whether the machine was cutting in climb or conventional mode.

[killrmodz]

Did you manage to cut those parts with the same machine and settings before the change of hardware?If the answer is negative then posting a few image files of the machine would be helpful as there may be factors originating from the height at which the Z axis is operating to the direction of cut.Posting speeds,feeds and depth of cut would be helpful,together with telling us whether the machine was cutting in climb or conventional mode.

Yes, never had issues when I was using steppers and external drivers. This issue came about when cutting slots for an oring channel in a part I was doing for a buddy of mine. When the job was done (had pocketing, contours, and boring) the parts that had radiuses had what looked like a stuttering... it's the best way to explain. When I made a test gcode program to pocket a 10mm circle, even at lower feedrates (200mm/m) the out of roundness is less but still there. It looks like it's trying to do a g1 to g3... if you were to look purely at the finished cut. Just very strange. Again, this came about after updating the bob and moving to clearpath sdsk servos. The servos were tuned (weighted) so it can build it's torque curve and to account for the increase in mass due to the increase in envelope of the new machine. Moved to linear guides and rails. Frame is square. When I disengage the racks & pinion gears, the movement of the axises are smooth and free of binding. This is why i'm so confused. The only things left is to either reload mach3 and start from scratch, or continue playing with my motor tunings in mach3 with the velocity and acceleration.

Thanks!