Right, so I am puzzled. I've noticed that suddenly all my prints are slightly askew, squares are not squares and I've decided to check if my gantry is actually square and beams are parallel/perpendicular. Surprise - they're not. While I was at it - decided to put a shim between bearings to get rid of the belt grinding issue. Next step - belt tensioning.
Tuned belts to same Hz and I've noticed that when they are at same frequency - gantry is not square anymore. I actually have to over-tense one of the belts quite some to make it square and keep it square as it moves across the range.
Has anyone ever seen similar behaviour?
#Belt tension vs gantry squareness?
versed meteor
proud edge
I have that issue. I plan to just use skew compensation to solve.