Consistent PTFE tube jams
Hi,
I have been using my Prusa MK3S flawlessly for over 3 months, but lately am getting a lot of jams, especially in the PTFE tube.
What have I tried?
- Replaced PTFE tube (multiple times)
- Replaced nozzle
- Cold pulls whenever possible
- Replaced heatbreak
- Replaced heater block
- Even replaced the whole E3D kit (needed replacement parts anyway)
However, even with the new E3D kit, still getting jams consistently. Have noticed though that in colder atmospheric periods, jams were occuring less often.
Sidenote: using grey prusa PLA filament, so no weirdness there.
Also, we can rule out erroneous gcode files since I am experiencing jams with the Prusa original gcode files that came with the printer.
Would love to hear some opinions on this, so I can get back to printing as before.
RE: Consistent PTFE tube jams
Enclosure type?
RE: Consistent PTFE tube jams
ps: and what is the ambient temp on the LCD display?
RE: Consistent PTFE tube jams
No enclosure, ambient temp between 27 - 35
RE: Consistent PTFE tube jams
Odd - my room temp is conditioned to 25c, and my Ambient reads closer to 40c. e.g., I have never seen it less than 35c unless I am not printing. Room is 24.6c and my printer is showing Ambient 41c ...
No suggestions to offer if your printer is that cold.
RE: Consistent PTFE tube jams
However, even with the new E3D kit, still getting jams consistently. Have noticed though that in colder atmospheric periods, jams were occuring less often.
That is very likely. The E3D V6 hotend is rated to operate at up to 40C ambient temps. As you approach those temps, the efficiency of the air cooled design is reduced, adding to overall heat. If the temp in the extruder approaches the glass transition temp for your filament, it can soften and cause more friction (and heat), skips and jams. It's a feedback loop at a certain point.
A quick test would be to try the same print with PETG and see if you have fewer problems. If so, that indicates the low PLA temps are a factor. You can try a number of things to reduce factors that contribute to heat. Adding external cooling, replacing heatbreaks, verifying extruder screw tension, reducing speeds, reducing retraction and other steps can help.
You may just want to designate summer as "PETG time" and save the PLA for cooler seasons.
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RE: Consistent PTFE tube jams
Odd - my room temp is conditioned to 25c, and my Ambient reads closer to 40c. e.g., I have never seen it less than 35c unless I am not printing. Room is 24.6c and my printer is showing Ambient 41c ...
No suggestions to offer if your printer is that cold.
Currently not printing due to.. a jammed PTFE tube 😛
But indeed it would be normal for ambient temps to rise a bit while printing!
RE: Consistent PTFE tube jams
However, even with the new E3D kit, still getting jams consistently. Have noticed though that in colder atmospheric periods, jams were occuring less often.
That is very likely. The E3D V6 hotend is rated to operate at up to 40C ambient temps. As you approach those temps, the efficiency of the air cooled design is reduced, adding to overall heat. If the temp in the extruder approaches the glass transition temp for your filament, it can soften and cause more friction (and heat), skips and jams. It's a feedback loop at a certain point.
A quick test would be to try the same print with PETG and see if you have fewer problems. If so, that indicates the low PLA temps are a factor. You can try a number of things to reduce factors that contribute to heat. Adding external cooling, replacing heatbreaks, verifying extruder screw tension, reducing speeds, reducing retraction and other steps can help.
You may just want to designate summer as "PETG time" and save the PLA for cooler seasons.
Tried with PETG (carbonfill though, maybe the regular PETG would fare better), and also getting consistent jams. As in: every time I try to print.
Before these problems arose, I have printed more than 1km of the same filament of the same vendor, so we can rule out badly manufactured filament.
I have a personal preference for PETG (no warping without enclosure), but use PLA a lot for prototyping. They are similar in price, so might go the all-seasons PETG route 😛
- Measured my filaments with a digital calliper and no surprises there.
- An additional possibility is that my filament might contain a little moisture / degraded just enough to stick (is about 1 month old, without storing in an enclosed box, but far away from UV light though.
- My extruder tension was verified, loosened the screw until filament doesn't catch, then autofill and adjust screw tension until filament catches, to ensure no overtightening (and thus no filament grinding). I tend to run my prints with the lowest feeder tension possible at all times.
- Heat break seems to be fitted correctly (its a new E3D kit, duh)
- Read in other forum posts that many others are experiencing jams, and they replace prusa heatbreaks by stock E3D heatbreaks. Just ordered one of those today 😉 @see https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-hardware-firmware-and-software-help/prusa-edition-heat-break-easily-jam-clog-with-pla/
- Speeds and retractions should be a non-issue in this case, since I am getting jams even with the default Prusa gcodes that came with the printer.
We have some cooler weather coming up in the weekend, so gonna try again this weekend.