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?
Looks like theres some other advice I’d try first but have you checked/calibrated the e-steps?
Esteps are easy to check, use a fine scale or calipers and a sharpie to mark the filament 100 & 110mm before it enters the hot end and then jog the extruder 100mm and measure how much it has actually extruded.
Tutorial here that covers pretty much every way to cal the steps but I suggest skipping from the set up down to the calculation and then to the “cowboy method” https://all3dp.com/2/extruder-calibration-calibrate-e-steps/
If that doesn’t seem to be the culprit you could try keeping an eye on it when you have time to see if material keeps oozing a little when the nozzle reaches the end of a tool path or during a travel. If so you can try tinkering with coasting and retraction settings. If defects seem to occur more during travels there are settings to avoid traveling over printed areas or you can try enabling z-hops.