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devilhunter
(@devilhunter)
Reputable Member
PETG cold pulls

Anyone else have trouble with PETG cold pulls?

Since i have no tension screws but a tension lever (Titan) it allows me to do a cold pull with every filament change.
This way i have no color residue from the previous filament on the new one.

For PLA this works great. drop to 90 degrees and get a perfect Nozzle tip on the filament pull every time.
ABS works with 140 degrees.

With PETG it always breaks.
80°C -> Filament breaks off in the melt zone
90°C -> Filament breaks off in the melt zone
100°C -> Filament breaks off in the melt zone
120°C -> Filament breaks off in the melt zone
140°C -> Filament breaks off in the melt zone
160°C -> Filament breaks off in the melt zone
dafuq?

Opublikowany : 19/05/2018 10:53 pm
thrawn86
(@thrawn86)
Honorable Member
Re: PETG cold pulls

its definitely a more stretchy filament, I don't even bother trying it with PETG.

Opublikowany : 20/05/2018 12:05 am
reid.b
(@reid-b)
Reputable Member
Re: PETG cold pulls

From the way you describe it, It sounds like you aren't doing a true cold pull. I do it with PETG the classic way- let the extruder cool down to no more than 40C, THEN heat it up to 120 and do a gentle pull upwards. Some PETG snaps every time (Prusa, cough cough), but my Filmentum cold pulls nicely.

Opublikowany : 20/05/2018 7:36 am
Gato
 Gato
(@gato)
Reputable Member
Re: PETG cold pulls

Good to know. Never did a cold pull so newbie question. Did you do anything to the extruder idler (or any other part)? Or all you have to do for a cold pull is what you described (playing with temperatures and use nylon or petg)?

thanks

Opublikowany : 20/05/2018 7:57 am
devilhunter
(@devilhunter)
Reputable Member
Topic starter answered:
Re: PETG cold pulls


From the way you describe it, It sounds like you aren't doing a true cold pull. I do it with PETG the classic way- let the extruder cool down to no more than 40C, THEN heat it up to 120 and do a gentle pull upwards. Some PETG snaps every time (Prusa, cough cough), but my Filmentum cold pulls nicely.

I've tried different ways many times, from 0 to x, x to 0, about 40 to x, i've never gotten this to work.
Tried about x different PETG manufacturers now (dasfilament, Prima filamentworld) , seems like none of them work so far.

Opublikowany : 20/05/2018 12:47 pm
devilhunter
(@devilhunter)
Reputable Member
Topic starter answered:
Re: PETG cold pulls


Good to know. Never did a cold pull so newbie question. Did you do anything to the extruder idler (or any other part)? Or all you have to do for a cold pull is what you described (playing with temperatures and use nylon or petg)?

thanks

PLA cold pull is very easy, but on the stock Prusa extruder it's rather cumbersome.

On the Titan you just push the tension arm and you can do whatever you want with the filament

On the Prusa you have to unscrew the tension screws first that release one bondtech gear

Go from cold nozzle to about 90 degrees, then pull and jank out the filament.
Should leave cone shape tips like this

Nylon is only required for if you've printed with some exotic filament and it left residue (like polycarbonate) or you have an almost lost cause nozzle.

Opublikowany : 20/05/2018 1:05 pm
Ty polubić
Gato
 Gato
(@gato)
Reputable Member
Re: PETG cold pulls

Thanks devilhunter for the detailed information. Releasing the bondtech gear is what I imagined would be needed. Good to know the process.

Gaston

Opublikowany : 20/05/2018 8:13 pm
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