TOS-KURIM CNC Upgrade

[JimJam]

I've finally been able to cut some metal last week!

Programmed up some test cuts, just a simple square with a holes in the center. purely just to check dimensions.

Getting a few strange issues and not sure where to start looking ....

The hole in the center is on size and position, but the flats across the square are 0.8mm undersize in the X and 1.8mm under size in the Y.

I've run various cuts with different size squares and its the same amount out every time.

I thought it was a coding issues as I'm using a MACH 3 post processor in OneCNC and running it on UCCNC, which from researching supposedly normally works.

Or is it more likely a motor/encoder issue?

[Muzzer]

You can presumably set the steps per rev in the motor driver to the wrong value. If you have 1:1 ratio in your machine it keeps the numbers simple (do you have a belt drive, I forget). You may also be able to set the pulses per rev or pulses per mm in your controller.

Good to cut metal but now investigate what is causing this issue. Is it (hopefully) a consistent % scaling error or a random (loss of pulses) error?

If it's a consistent scaling error, you should be able to fix it by correcting the settings in the drive via the software. I don't know Mach3 but there may also be some settings in there. If you swap over the X and Y signals, you will see where the scaling error lies - does it stay with the drive or within Mach3?