The photos bellow show how a failed print tells a potential story and can lead to success! The extreme cavitation or whatever you want to call it, caused the layers to not fuse properly or there wasn’t any plastic flow but what caused that? I figured I would take apart my extruder to see what was happening, after all I built it and know every bolt.
Here is what I found:
-First it was a fun thing to do on a Saturday afternoon with some coffee!!
-The cartridge bearing that supports the axle of the extruder motor had released some of the grease that it was packed with when it was originally assembled at the factory; I expected to see this when I took it apart. This could have caused slipping or contamination but it is difficult to tell as the drive gear was grease and debris free. While cleaning the grease was a nesseccay step as it had some plastic fragments in it and that could have lead to contamination later, I feel this is inconclusive but a worthy cleaning step never the less. A bit of acetone to wipe it clean off.
-Next I looked at the filament drive gear to make sure it was catching the filament properly. Simple enough but there wasn’t any debris in the hobbs to prevent engagement or to cause slippage. I gave it an acetone wipe also. Again, inconclusive but a worthy task.
-Then I considered the spool jaming on the filament wind itself. It looked like as the filament came off the spool it was under itself causing drag. This could lead to the printer head lifting a small amount causing lack of fusion in layers, but my spool turns quite freely. Yet again inconclusive but I spent a second and fixed it easily.
So now I have run the same print and have had much better results. My regular amazing results I expect from my machine. I love my Makerbot Thing-o-Matic! I learn from it as much as I build with it and both experiences are so satisfying! Once again this machine astounds me at every print!
In this photo you can see the missing or malformed plastic.
This photo shows the resulting run after cleaning and a slight filament rewinding. Much better!