SP4 XXL not square - fix in code?

CNC Machines Shapeoko 4
1

So, lets assume for a moment I have a SP4 that has a gantry that is out of square by ~5mm over 990mm diagonal. The machine appears STABLE, so that it doesn’t randomly change shape, but its shape is not square, it is a parallelogram. Also, X0 → X700 is the same as X0,Y700 → X700Y700 to within .2mm. Also, Y0–>Y700 is the same as X700,Y0 → X700,Y700.

My options appear to be:

  1. manually tweak the gantry by loosening screws and tightening screws until that skew goes away enough for me to be “happy” and move on.
  2. Get angry, then do #1.

But… isn’t there someway to fix it in code? Shouldn’t there be a simple setting that tells the machine “I’m actually 1.2374 degrees out of square. If I want to make a horizontal straight line, I need to move 100mm in the X and .021343m in the Y.” Don’t 3d printers do something like this?

Shouldn’t that be easy to do? Does that ratio already exist in code like the stepper # does and I just can’t find any reference to it?

And, if there isn’t, I’ve seen some online descriptions on how to square the machine, and they mostly seem to be either SP5s, or SP3s. Is there something specific to the SP4? or no?

Thanks,
mw

2

Grbl doesn’t have code for this — it just has steps/mm for each axis, not the code for doing trigonometric calculations to adjust for the machine being out of square.

Squaring the SO Pro is the same as for any other machine w/ a Hybrid T-track table — loosen all the hardware, if need be, loosen the belts, gently push/pull/nudge it into square (verify by measuring the corners), then tighten the hardware, then tension the belts.

3

SO4 XXL, not pro, but I’m assuming your answer is the same…

4

The SO4 and SO Pro both use the same Hybrid T-track and base frames and so forth — difference is the endplates and the presence/absence of the linear rails and attendant parts, so yes, the same.