[justicedavid65]

I started a thread a few days ago asking questions about my DIY machine and got some help. I'm down to just one issue plaguing me, so I wanted to start a new one.

My machine is 1500mmx1500mm all 1610 ball screw and 15mm linear rails. C Beam on Y axis and dual C Beams on the X. My machine is square, measuring corner to corner both are the same. I can square my gantry by moving it to the front of the machine and touching both side to the front plates (I've attached a picture just so you can see what the design looks like). After squaring I can jog the gantry up and down the full length of the frame many times and everything is fine, but if I run a g code file, 'air cutting' the gantry will get out of square very quickly. I've tried circles and squares and both cause this.

I can't tell which side is causing it, or if it's both sides? I can't hear or see any stalling or loosing steps.

Any ideas? or troubleshooting techniques to figure this out?

Thanks!