I have TAZ5 with BLTouch and I noticed that my Z offset is getting skewed on the right side.
I did bed levelling (adjusted X rail height on both sides and bed corner a bit, and got decent bed level).
Then I ran couple of prints and re-ran the calibration sequence and my right side went off quite a bit…
Could this be the servo issue or the coupler is broken or something else ? How do I even test any of that ?
If your lead screws aren’t lubed well, or the frame isn’t square, it could be binding (usually toward top or bottom) and going out of plane with the bed.
You may have some slight top to botttom frame racking that makes it lose micro steps as the drop on the wire to the right motor drops the power it can supply to that side. When I used to refurbish the retired farm priters for resale (6 or so years ago) I ran into a number of them that exhibed this problem.
I think I found the problem. Trying to fix it is a different story. I upgraded x axis with 12mm rods and while everything fits ok, my set screws didn’t bit into a rod. Rods are quite loose. I think belt is pulling on one side and probably pulls the lead screw ever so slightly that stepper skips some times. I tried running gantry up/down but it seems only micro steps are the problem…
On the fix side, my set screw seems to be pulling threaded insert out and therefore not enough friction to grab on the rod. I might need to redesign the brackets with nut inserts and use normal pointy screw…
