We’re having quite some issues with our extruder.
PROBLEM 1: (SOLVED)
The small lever used to regulate the pressure of the filament onto the extruder screw kept snapping if there was too much continuous retraction movements shaking it all around.
-Solution:
We tied the lever (through the small hole) onto the pressure calibration screw using a wire.
Note: Will need to be replaced after winding on and off the calibration screw a few times.
PROBLEM 2:
The extruder screw bites into the filament about 10 - 30min into a print, and by doing so, it stops extruding filament. When dismantling the extruder, we could observe how the teeth in the extruder screw were completely filled in with plastic, the filament presents a notch about 1mm deep.
-Possible Solution:
We’ve been working on making a new extruder screw out of harder metal. We have yet to determine the best combination of tooth factors(depth, point angle).
PS: We have contacted 3DStuffMakers about this and we were offered to buy the upgrade kit (which includes a extruder on the y carriage) along with a bunch of other stuff that must be upgraded too… So we figured, let’s make a better one!
PROBLEM 3:
The piece of plastic which makes physical contact with the filament, pressing it onto the extruder screw, is getting worn into the contour of the filament. We suppose this increments the friction between the filament and this piece, and therefore requires the extruder screw to grip more than it can. This is potencially the source of PROBLEM 2.
-Possible Solution:
After giving it some thought, it seems pretty clear we should design and print a replacement part before it’s too late. Any voluteers? 
What are your thoughts on these?
Any ideas on other solutions?
Have you experienced any of these?
