My Micro Swiss arrived from The 3d Printer today (express post!), so I installed that.
While the extruder block was disassembled I noticed that the spring on the tensioning arm was really wimpy, so wimpy that it didn’t even leave tooth marks behind on the PLA. Since this could be a contributing factor to the extruder skipping I’ve been experiencing when printing solid layers, I swapped that spring for a much beefier one.
After these two changes I found that some old and new problems have joined me:
- The vertical vibration ripples have come back.
- These ripples have been joined by a new set of ripples, this time going -45° diagonally on all sides.
- The nozzle offset is now different, and I need to work out the new one so that the nozzle homes in the correct spot. I’ve moved the glass sheet over for now.
- The extruder still skips while laying down lots of plastic for solid layers.
Possible causes: Vibration
- The new Micro Swiss nozzle is shorter than the old one, so I’ve had to crank the bed higher than before. Less spring tension means more bed wobbling.
I have a 12 V blower installed as the part cooling fan and it’s starting to make funny sounds since it’s hooked up to 24 V. Maybe it’s rattling and causing vibration? I tried a print with this fan turned off and it halved the size/depth of the vibration marks, but doubled their frequency.
- I wrote several posts ago that Y bearing/s (I think it’s the two on the left side) had developed play in the Z direction, and also started to make loud rattling/scraping sounds during rapid moves. This could be introducing vibration.
- The extruder block may have been reassembled improperly.
- The stiffer spring on the tensioner arm might be misaligning the plastic parts of the extruder assembly.
Possible causes: Extruder skipping
- The heater block may not be reporting the correct temperature. I have noticed that skipping reduces — but doesn’t disappear — when temp is increased by 20 °C. Needs PID tuning.
- The motor may be dying.
- The motor may be running with too little current or voltage.
- The (brand new, by the way) nozzle or heat chamber may have some debris inside them from the factory. Do a cold pull and a full clear.
- The extruder pulley and toothed wheel could need lubricating.
- The toothed wheel might be wasting torque by being so large. Printrbot’s extruder gear was far smaller.