Continuing on with the theme of “stuff I should have known better but did anyways.”
I was diagnosing a problem a few months ago and decided that I needed to remove my extruder and disassemble it. I sat there, next to my printer, trying to find some space on my tabletop among all of my other printer accessories.
I checked everything. Motor gear? Good to go. Extruder gears? They are metal, but let’s check them anyways. They are good to go. Motor? It has the right voltage and it’s turning. No clog on the hotend. It’s good to go.
I decided to come back to it later.
When I came back to it, I still couldn’t figure it out so I contacted the manufacturer. They told me a few things to look for. I checked them but my extruder still wasn’t gripping the filament properly. I decided to put one of my old extruders back on (good thing I save them for just such a scenario).
When I pulled the old extruder out of my drawer and I happened to look down on the floor. There I saw it. A bearing. I knew immediately that this was the cause of everything. I must have dropped it when I disassembled my extruder and I didn’t notice. It turned out to be the bearing that holds the motor gear against the motor. When I didn’t notice that it was missing the filament was able to push the gears away, causing it not to grip properly. As soon as I put it back in everything started working again.
Save yourself some trouble. Disassemble in a clean area (not on a countertop, I have another story about a sink drain). Place all of your parts on a clean, light-colored cloth so that you don’t lose parts and they don’t go rolling off.