Filament jammed around pulley...  

Re: Filament jammed around pulley...

Are you using flex-filament ?

And be sure that your hotend fan is running certainly !

Thomas

Re: Filament jammed around pulley...

No, this is just the Prusa gray PLA. The hot end fan seems fine. I do have an enclosure so the ambient temp was warm, but... I wouldn't have expected this. Thanks.

Re: Filament jammed around pulley...

How warm ?

If the ambient temerature is too high this can be the issue.

Never print PLA in a warm/hot enclosure.

Thomas

Re: Filament jammed around pulley...

Thanks. It was about 30C ambient temp in there. Perhaps that was too high.

Any thoughts on how to approach clearing the jam?

Re: Filament jammed around pulley...

30° is OK, but not much more.

Test it.

Hmmm, dismantling the Extruder and cleaning it from the PLA ? Sorry, no real idea about this.

Thomas

Re: Filament jammed around pulley...

Ah, one side of the enclosure for the pully (the "extruder idler"?) is set up as a door that swings open! So, two screws and I have access. Maybe it's just obvious but I had started loosening other bolts before I realized that 🙂

Re: Filament jammed around pulley...

So I was able to remove the jam, but on the next print it did the same thing. I don't think the ambient temp was too high... maybe 26C. I am wondering if there is something wrong with my extruder or pulley.

EDIT:

Or is it more likely that I have a clogging nozzle and that is putting backpressure on the pulley causing it to slip and mangle the plastic? Upon clearing the jam and reloading the nozzle seems ok.

Re: Filament jammed around pulley...

Is this really molten PLA or is it (maybe from the bondtech pulley) debris ?

Thomas

Re: Filament jammed around pulley...

Are you trying to remove the filament after the print? Is this why the end is so high up?

I had a problem the first time I tried to remove the filament. I didn't pull it out fast enough. I find that I have to have tension on the filament as I select the option to unload.

Re: Filament jammed around pulley...

Not sure exactly what you mean but no, I wasn't removing the filament. During a print it just starts clicking and gets jammed. This is happening to me now every time I print after about an hour. The printer is at room temperature and the hot end fan and print fan are both running fine. My IR thermometer shows the pulley internal area at about 38 or 39C. I don't know if that is normal or too high for some reason... I've never had this issue with any other printer... it's frustrating.

Re: Filament jammed around pulley...

Are the tensioner screws with the springs too tight? They are supposed to be loose fitting and just engaged with the springs.

Re: Filament jammed around pulley...

Can you check the extruder motor temperature after every hour of printing.

Maybe the stepper is getting to hot.

Thomas

Re: Filament jammed around pulley...

Are the tensioner screws with the springs too tight? They are supposed to be loose fitting and just engaged with the springs.

I'd also recommend ^^^ that ^^^ to check that the screw on the pulley is not too tight. I had the same problem like you.

Re: Filament jammed around pulley...

Some more info:

I have printed a test object three times in a row now and each time at exactly the point I the filament starts slipping (clicking) and jamming. It's about an hour into that hexagonal 3D test print when it's doing the dome shaped overhang... So I don't know if it's just the time / temp or if it's due to slowing down the print at that point (I sliced with Simplify3D). At that point the extruder motor is hot to the touch, about 125F, but not scalding. I have unplugged the filament sensor since I read reports of that element heating, but it still did the same.

As suggested above I will check the tension... I'll have to read up on how to do that since I did not assemble this.
thanks.

Re: Filament jammed around pulley...

The two screws with the springs seemed appropriately tight. As an experiment I tried loosening them quite a bit (springs just barely engaged) and the print started slipping immediately.

Re: Filament jammed around pulley...

You can also try the prusa support, since you have a pre-assembled machine, this should not happen. However, things can get quite shaky during shipping so... whatever s#*t happens. But really... try them.

Try the Screw in the blue circle. That it actually not for the pully itself but for the swing door... but if there is too much pressure on the wohle construction, the pully also may get stuck anyway.

http://manual.prusa3d.com/Guide/5.+E-axis+assembly/510?lang=en#s8191

If that does not work, try some Voodoo I lossened the TOP two screws in the orange circe just a bit, to release some pressure from the whole assembly. Don't make them too loose though, you dont want wobble on your extruder. 🙂

https://d17kynu4zpq5hy.cloudfront.net/igi/prusa3d/h4NGGYYgQxTdiFVX

Re: Filament jammed around pulley...

Rescale your test object to 150% and print it again.

Starts the slipping exact at the same time as your last test prints, it's a matter of time. If it starts at 150% time, it's a matter of your object.

Thomas

Re: Filament jammed around pulley...

You can also try the prusa support, since you have a pre-assembled machine, this should not happen. However, things can get quite shaky during shipping so... whatever s#*t happens. But really... try them.

I'm unclear on the best way to get support from Prusa. This forum is labeled "official support forum", but I haven't seen prusa reply on it. I have emailed them about other issues but it takes many days for them to reply and they are very terse...

Re: Filament jammed around pulley...

There are replies but very sparing. Go to the e shop and a chat window will display bottom right open and submit abs you'll be chatting in time

125° is about right for the extruder motor. Here's pix at 16 hrs into a print. Right at the 125° mark

https://photos.app.goo.gl/cSXQplMtbSkkkGV73

Almost sounds like an issue with the heat break. I would be checking out the noctua and heartbreak area.