Makerbot down! We have a makerbot down!

I’ve only had the makerbot for a month now, but it’s refusing to print. Sigh. I know it’s a diy kit, but this little puppy only had three whistles printed on it before it rolled over, ready to die. Here is my thought process as I go about trying to fix it.

Symptoms: The extruder would no longer extrude. RepG registers 220 and the hot end seems to settle nicely there. The motor turns on but nothing comes out. I have a mk4 extruder and was in the process of printing a wade’s extruder when the symptoms started (do you think it got jealous?) If I grabbed the filament with pliers then I could push plastic out the tip, but it also squeezed out between the pfte insulator and the brass barrel.

My Diagnosis: After adjusting and re-adjusting the difficult pressure wheel on the mk4 I settled on the idea that the tip must be partially blocked or not hot enough. I took it apart and broke the brass barrel in two. Then I made a new barrel out of a bolt and bought a new barrel (two path approach!)


Here you can see that the nichrome wire has burned/melted the kapton tape. Is that normal?

Results:
None good. The stock barrel behaved exactly the same. It would flow, but weakly and only with considerable pushing on my end. The new hot end I made fared about as poorly. I tried to re-use the nichrome wire from the original hot end build, but at some point it had burned off its coating and this was very problematic.

Next steps:
1 – rebuild stock barrel/ptfe combo
2 – test resistance of nichrome on new barrel
3 – buy and build wades extruder
4 – use both extruders on mk4 setup to see if it is the hot end, then swap in the wades extruder to see if it is the motor.