Issue with 4'x4' pro build

[djdelorie]

This is normal; welcome to the club

You have two options.

1. Let the motors force the gantry into square with software, either by adjusting the sensor stops or by calibrating it out (I’m not familiar with mach3 enough to know if it has a setting for that; linuxcnc does)

2. Shim the gantry into square, which means taking it partially apart. I had an old thread where I went through this, but in my case, a 0.006" shim on both ends took out most of the twist… You end up loosening the red vertical plates just enough to shim under one side or the other.

Manually squaring the gantry's "resting position"

I’m getting down to the tuning details on my 60120 build, and have measured the gantry at being 0.125" off of “square” - i.e. if I home the Y axis to square it (to within a few thou over a few feet, no problem there) then kill power to one of the motors (servos), that side of the gantry moves 0.125" to “relax”. The typical advice to deal with this is to shim the gantry, but then you need to know which riser(s) is causing the offset, etc. Is there an alternate set of steps I could to do adjust …