Filament jam after every print

I have a Prusa i3 with a MK8 extruder. I am printing using PLA with an extrusion temp of 210C. My prints are coming out fine (despite ocasional clicking in the extruder), however every time after a print the extruder is jammed. Its not the nozzle that is clogged, but there is extra filament curled up in front of the cooling fan. This is easy enough to fix, i just have to take it apart, pull out the filament, cut off the end then re-load it. Doing this every single time is getting anoying. Is it something wrong with the machine? or am I missing a step? or do i have firmware issues? how do i fix this?

Usually filament forms a blob in the nozzle that's slightly bigger than the filament diameter. When retracting too much it may get stuck in the cold end/heatbreak. See in the gcode at the end if it retracts more than normal retraction. The slicer may have some retraction defined in the end gcode part.

The filament curls between extruder gear and heatbarrier?
I've seen pictures where the heatbarrier ( the hollow M6 screw ) is not screwed all the way up to the extruder gear.
If there's a gap between gear and heatbarrier, the filament tends to curl. Then the stepper starts to click, because it can't extrude anymore.
If you can't screw the heatbarrier further up, try to add a short PTFE tube as filament guide.
-Olaf

Also, 210C seems a little high for PLA, what brand are you using?

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o_lampe
The filament curls between extruder gear and heatbarrier?
I've seen pictures where the heatbarrier ( the hollow M6 screw ) is not screwed all the way up to the extruder gear.
If there's a gap between gear and heatbarrier, the filament tends to curl. Then the stepper starts to click, because it can't extrude anymore.
If you can't screw the heatbarrier further up, try to add a short PTFE tube as filament guide.
-Olaf

My heatbarrier is not screwed all the way up to the extruder gear. You described the problem perfectly. I'm sure I just need to screw it in more. Unfortunately I broke my extruder gear as I was trouble shooting (striped out the set screw) so I won't be able to try this fix until Monday.

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widespreaddeadhead
Also, 210C seems a little high for PLA, what brand are you using?

I don't remember the brand, it's one of those cheap Chinese No-names. I did some experimentation with temp. And found that my extruder would click if the temp was 203ish or lower. 210 seamed to work ok. Maybe fixing the heatbarrier will help the temp issue somehow, or possibly the new extruder gear. The one that came with the mk8 was soft brass I have a high end stainless steel one coming.

Thanks guys! I'm super excited to get this working. Being able to print more than one thing a day is going to be awesome.

I got me an M4 tap and started to change all the grubscrews to M4. The allen head tools for M3 grubscrews don't last long in my hands....
-Olaf

PS: Actually brass is much harder than steel, it's even a bit brittle. That's why steel is easier to work with.

Edited 1 time(s). Last edit at 10/15/2015 03:16AM by o_lampe.

I had this problem recently and found that it was because my cold end was getting too hot and while the heat was on for the first time it would still push through, but after it cooled and hardend it wouldn't remelt...

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Qdeathstar
I had this problem recently and found that it was because my cold end was getting too hot and while the heat was on for the first time it would still push through, but after it cooled and hardend it wouldn't remelt...

I had this problem once or twice too. I had to use a blow torch to fix it.

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AudaciousTuddle

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Qdeathstar
I had this problem recently and found that it was because my cold end was getting too hot and while the heat was on for the first time it would still push through, but after it cooled and hardend it wouldn't remelt...

I had this problem once or twice too. I had to use a blow torch to fix it.

Yeah, the problem was I had printed a fan to cool the prints, but it partially blocked the intake of my cold ends fan.... So had to take it off and rethink my design.

my problem was that i had the slicer misconfigured, it would try to run without the fan. i just had to manually turn the fan on for all my prints