(Solution, FYI): MMU3 layer shift from dripping filament
Problem:
Cheap filament, high temperature, large nozzles are a recipe for dripping during filament change (Picture: PETG, 0.6 mm, 260 degrees = max. recommended printing temp for this material)
A solid blob forms on the wipe tower, partly melts into it but eventually catches the nozzle. Layer shift results, or the wipe tower might get knocked over. If the wipe tower surface looks unusually bumpy, this may be the reason.
Solution:
- This "tool change G code" that parks the nozzle in the door corner of the print bed, next to where usually start-of-print purge takes place
G1 Z{layer_z+15} X250 Y0 F5000
- A fingerprint (or e.g. heavy glue stick as separating agent) in said corner to prevent the blob from catching the nozzle. The head cannot move over it so chances are good it'll get knocked outside the print area.
