Filament snapped above extruder gear???

[Quark]

Has anyone had this happen to them? I've been trying out eSun's PLA and had the filament snap before the extruder gear. I cannot tell for sure exactly when this happened, as I was printing remotely, while an assistant cleared the prints of the bed. I had him take the last print off the bed, and I started a new print, only to find out that nothing was being layed down. While on the phone, turns out, the filament tube was dangling in the air. The spool wasn't stuck or anything, and the previous print seemed to have printed fine. I re fed the filament in, and got right back to production, no nozzle jam or extruder jam. The part that snapped, looked real clean with no extruder bite marks. Really bizarre, maybe a defective spot in the filament? Still though, would have taken quite a bit of force to snap a filament, and I think the gear would have stripped the filament before it snapped. Tension is good. What would cause this?

[Jules]

Yep! Seen it happen twice - once with a spool fresh out of the package. It's caused by the filament absorbing too much moisture. It gets brittle over time. (And apparently sometimes during manufacture - might have been a rainy week or something.)

Recently had it happen with an old roll that i left out in the air for too long too. If you put it in an airtight container with some sort of dessicant package and leave it there for a while (like a couple weeks) it regains enough flexibility to use it without any problems.

[Quark]

thanks for the reply, I knew someone had it happen. This was a fresh spool too, and I thought it was moisture, but I tried to snap it a few inches near by, and it just bent. Maybe a drop or liquid or someone's spit landed on that spot of the filament?

[Pekish79]

u called it i just had it happen ^_^ i left the print overnight so i am not sure how/when is happened but the print was less then half done (15 hours prints)

I am printing some different color now and going back to him tomorrow or the day after for another try while he sit in my magic box trying to get dry again

[Quark]

Ouch, the filament gods must not be playing nice this month.

[Pekish79]

today i tried the print again same filament that snapped the other day
this time it worked find i think it was just a weak point in the roll... guess it may happen that filament is low quality one anyway (is the cheapest of the wood pla)

I am printing the surrounding building with it just to use it all since is impossible to use it for the main project but overall easy shape if u clean the filament dirt it leaves everywhere it doesnt look bad missing only 1/4 of the site 3/4 already done



this is as big as i feel comfortable to go without wasting too much time 35cm x 40cm (13-3/4" x 15-1/2")
if you keep in consideration the clip to hold zebra plate in place and stuff the maximum u can realistically print is 19x22 those are 4 piece 17.5cm x 20cm

each of which at my low speed setup take 10-13 hours

[Quark]

that is a cool use of the wood filament. I wonder if putting the spool holder on bearings would help reduce the stress? It seems free moving enough as it is though. I seen one out there on bearings.

[Pekish79]

actually mine is the one with the bearing

http://www.thingiverse.com/thing:984369

i made it in white and yellow the bearing ahah anyway i highly suggest it is super easy to do and it help having smoother filament movement

(this is the 4th large print 20 hours!!! is the piece with the biggest building in it)

it still breaks as it happened to me but before using the bearing i had 2 print fail because the filament got stuck due to weird angle between the roll and the guide

after that i did the bearing and it's very smooth in the movement

[Quark]

oh, that would work too. I meant this one from jdacal.

http://www.thingiverse.com/thing:523415

[Quark]

So I just had the same spool break on me again. sigh, so frustrating. This time, it snapped above the extruder gear, AND there was a partial break inside the filament tube. Leads me to believe the breaks are already there? Pretty sure it isn't moisture absorbed as every other section prints fine, its about a week old, and inside an environment controlled room 60% humidity (its inside my datacenter right now... )

I'm tempted to unravel the entire spool to see what it looks like. I know eSun makes decent PETG, just never heard much about their PLA. Maybe I got a dud?