Layer shifting with MMU3
I have recentlyupgraded Prusa slicer to 2.9.4, and the core1 firmware to 6.5.3 together with the latest version of the MMU3 firmware. I am now experiencing random layer shifting when using the MMU3. Prior to this I have printed items with 100s of filament changes with no problem. I have checked the belt tensions. |On my latest failure I noticed that the wipe tower had a "lumpy" appearance, image attached, and that the print head eventually fouled one of these lumps causing a layer shift. I suspect that this is caused by the latest upgrade to the slicer. Is this the most likely cause?
Is there something that I should change in the slicer configuration, or should I go back to a previous version?
Any help appreciated.
RE: Layer shifting with MMU3
Further analysis suggests that this is caused by an excessive amount of plastic being extruded during the filament unload process. I don't understand the details of the filament unload sequence. Is this controlled by slicer (in terms of the Gcode generated), or by the printer firmware executing a preprogrammed filament unload sequence? If a preprogrammed sequence, are there parameters generated by slicer to modify/control the unload sequence?
RE:
if it's a blob on the wipe tower - common problem - you can do something along the lines of
G1 X10 Y10 Z{layer_z+10} F3000
in tool change G-code so the blob drops into the corner of the print bed not the wipe tower. A strategically placed fingerprint on the print bed prevents it turning into a "hard" obstacle to the printhead.
Moisture makes the dripping worse - make sure filament is dry.