printer stopped extruding filament half way into print job

[s4sythe24]

I have an issue with print jobs and it started to print and then not even half way through it stopped extruding filament and was printing “air”. The filament spool is brand new and there were no kinks or tension on the filament. I just replaced the extruder/nozze/tube part and it has been printing ok. I can refeed the filament and then extrude out several lengths of filament just fine.
What would cause this happen and this has happened several times before.

[Tim]

There can be multiple reasons for jams: (1) not enough tension on the bolt pressing the filament against the gear drive, (2) fluctuations in the diameter of the filament, (3) temperature too low, (4) surface of print warping and pushing too hard against the nozzle, (5) poor quality filament, (6) gunk in the nozzle not flushed out after a previous print, especially if the type of plastic was changed, (7) printing too fast or in any other way attempting to extrude more plastic out of the nozzle than the combination of nozzle, plastic, and temperature can handle.

It's a bit difficult to put those into any order of likelihood.

Given that you were working with a new spool of filament, I would point out that every spool of filament can be different, so possibly your new spool of filament just wants to be printed slower or at a higher temperature than other spools you may have been using.

[jimc]

One other thing. This is less likely with pla but very likely with other plastics.....the tension can be too tight on the filament. The bearing squishes the filament into an oval making it tight and jams up.