Yea, I’ll check the motors for correct wiring, ND I’ll retest the belts. It printed fine before the rebuild,Almost seems like the roller is flexing to much.is there a magic trick to testing for squareness? I run the z torture test that Ryan put out a few months ago, and about halfway through it will catch and bind and jump step. Mainly on the x axis, which is the longer one. There shouldn’t be an issue with using the old z with the new corners? I notice that the rollers top bearings are touching but usually only one of the bottom 3 is touching on each opposite roller?