Started printing this filament shrinkage test and had to leave the house. When I came back, the whole upper half of the part had shifted after the first few layers, and it left two solid blobs attached and one ball of spaghetti. The magnetic bed doesn’t appear to have moved. Part is still solidly adhered to the print bed. How did this happen, and how can I keep it from happening again?
Did you hot tighten the nozzle while putting it back? Don’t think it caused your current failure, but cold tightening can lead to more clogs in the future.
I think layer shifts can be caused by many different things, but the first thing I’d check is that the bed carriage can move freely and there isn’t something mechanically blocking it, like a wire or a misplaced screwdriver. The second thing I’d check would be the belt and gears, so that the bed can’t move without the stepper motor also spinning.
I hadn’t heard of tightening the nozzle while hot, but I’ll definitely give that a try
Thermal expansion is real. Have experienced loose nozzles when only cold tightened. Also as others have said, ensure belts are tight. If they’re floppy enough to skip teeth on the steppers you’ll definitely get layer shift from a light breeze. Monitor the next test and let us know how it goes!