Do you have a video or instructions you went off? I feel like this is probably my issue because both times this happened the unit had been running for a few hours.
I think i need to make a few adjustments to the belt tensions and mess around with the step motor voltages slightly to get where i need them and where i want it, but this sounds like it may be apart of the problem as well.
Another annoyance i have been seeing is the dust which covers the step motors and belts on the y axis...has anyone come up with a solution to prevent this? Understand I still haven't make my dust boot, which i know will help significantly.