Unload Jam Damaged Filament Sensor
I just had a major jam attempting to unload the filament after a spool ran out. The filament apparently didn't make it back up into the top PFTE tube on its way back out and instead got jammed into the filament sensor and wedged across into the hole across from the sensor (this was accompanied by a horrible cracking sound). After taking the feeder door off and pulling the filament out (not an easy task) I reassembled everything and it no longer recognized the filament sensor. The upper PFTE tube was also deformed on the bottom so there was a significant amount of force involved.
I'm going to contact support for a replacement sensor but how can this be prevented from happening again? If the end of the filament isn't perfectly straight (and considering that it's wrapped around a spool at the inner most radius then that's likely) it's surprising this doesn't happen more frequently. It also seems like it would be better to simply have it just push the remaining filament out the extruder, no? I realize this could cause a jam if the two ends of the filaments don't line up but that seems like it would be less destructive that what happens going the other way.
Re: Unload Jam Damaged Filament Sensor
Wow - I can see the last bit of a spool having a jagged bend that would probably sucked down into the works. A cautionary tale if that ever happens to me. I'll pull the filament manually out the side by the idler. Then do a thorough test of the sensor board.
Not sure of any way to prevent this happening again unless you enable the filament sensor; even then that jagged end has to go by the sensor to work.
That leaves inspecting every spool to make sure the filament coming out the inner spool is cut off as straight.as possible.