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heat creep

Posted: Fri Nov 30, 2018 12:30 pm
by goman
I had a problem with heat creep and it does help to lower the temperature of the nozzle for PLA pro (esun).
i thought perhaps that the tubing on the filament guide might cause some insulating effect contributing to the heat creep.

i thought to make sure i would simply make it so there was more air space around the filament approaching the extruder keeping the filament slightly cooler where it entered the hob nut. It cost nothing so i thought worth a try. I put a small ball point pen spring and a washer at the insertion point of the filament. pics included.

I don't know if this works yet as i haven't actually tested it.

Re: heat creep

Posted: Fri Nov 30, 2018 3:55 pm
by fastrobplus
From the photo I'm assuming this is a Taz 6 with the single extruder.
I have that configuration and have never had heat creep issues with E-Sun PLA+ pla (I use the polymaker PLA default settings in Cura). Actually I've had very few heat creep issues ever with this printer and extruder. Much more common on my mini.

FWIW, I kept having an issue where the PTFE tube would get "sucked into" the hobbed bolt and get chewed and clog the printer. I finally got frustrated and cut about two inches of tube so that under normal use, the tube gets anywhere from 4 inches to an eighth-inch from the mechanism but never gets sucked in... I do notice I get occasional issues where the "bare" PLA not protected by the tube suddenly snaps in half, almost always at the beginning of the print. I don't know what's up with that exactly.
Anyway, I'm not convinced that the tube in any way insulates or contributes to heat creep. My trial and error tells me that (in approximate order) it is a combination of the following:

- Not enough cooling from the fan onto the heat sink.
- Tightness (or lack of tightness) of the idler screws.
- Grunge in any part of the hotend extrusion path. (use something like cleaning filament and cold pulls to clean)
- Matter in the teeth of the hobbed bolt.
- Possible need for lubrication in the extrusion path. <- ProtoPasta swears by this and their HTPLA far more susceptible to heat creep issues than eSun PLA+. I visited their factory last month and they even gave me a gel-cap nutritional spam (some kind of oil) to drizzle onto the filament to help lubricate the pathway.

Re: heat creep

Posted: Sat Feb 09, 2019 2:32 pm
by ajrobertsx
I have upgraded both my Standard Taz6 and Dual V3 extruders with new fans. Lulzbot sells the pins. Here https://www.lulzbot.com/store/parts/mol ... al-pin-x30

Before my V3 nozzle could only print for about 40 minutes before nGen got melted in the heat-break (1 plug was almost 11mm long). Last night I ran a print that ran over 16 hours and it worked. Longest and one of the prettiest print jobs ever on my Taz6.