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How do I keep PETG from building up on the hotend?  

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Steve
(@steve-4)
Estimable Member
How do I keep PETG from building up on the hotend?

I am getting buildup of PETG on my nozzle and hotend.  I am print through Octoprint and using Prusaslicer.

What am I doing wrong, and how do I stop this?

 
This topic was modified 2 years ago by Steve

Senior Life member of IEEE.

Posted : 19/06/2022 12:14 am
Steve
(@steve-4)
Estimable Member
Topic starter answered:
RE: How do I keep PETG from building up on the hotend?

Senior Life member of IEEE.

Posted : 19/06/2022 12:15 am
m1crochip
(@m1crochip)
Active Member
RE: How do I keep PETG from building up on the hotend?

Steve.... That's ridiculous.

Posted : 15/07/2022 8:14 pm
Diem
 Diem
(@diem)
Illustrious Member

You have a Blob of Doom. Search for blob of doom to see how others have dealt with them

To remove it:

Raise the nozzle temperature to the printing temperature for the filament in question and allow it to heat for several minutes.

If you are lucky you will be able to prise the blob open - more likely you will need to add heat from outside with a heat gun to aid the softening, sometimes it's worth using a soldering iron to carve chunks off the mass.

Use needle nosed pliers to prise this away; remove it in parts if it won't release the wires.

Once you have the worst removed you decide whether you need to disassemble the extruder to get at all the blob or perhaps you can clean up in situ.

After the cleanup there will be overcooked filament inside the nozzle so at least a purge and probably a cold-pull will be necessary.

The commonest cause is poor adhesion and it is usually fixed by recalibrating the first layer Z ...

So once you've cleared it run a first layer Z calibrtion and if you are unsure about it post a picture here while it is still on the print sheet.

Cheerio,

Posted : 15/07/2022 8:40 pm
Steve
(@steve-4)
Estimable Member
Topic starter answered:
RE: How do I keep PETG from building up on the hotend?

So that's what's called.  I should make little temple for it so Harrison Ford can mess arourd in there.

Anyway, I got it off, and cleaned up the hotend, but was curious what causeses in the firsr place.  In doing so, i discoveded there was no cooling shoud on the hotend,   I printed one using PC blend and that worked fine. So I guess problem solved 

Senior Life member of IEEE.

Posted : 16/07/2022 1:32 am
Diem
 Diem
(@diem)
Illustrious Member

Blobs of Doom do consume fan shrouds from time to time.

Under the 'Hall of Fame' heading there is a 'Hall of Shame' thread where people post their finest Blobs of Doom...

Cheerio,

Posted : 16/07/2022 1:53 am
Steve
(@steve-4)
Estimable Member
Topic starter answered:
RE: How do I keep PETG from building up on the hotend?

This fan shroud was never on there in the first place, which explains a lot.  I think I'll print another in case  I mess up this one.

Apparently, the fan shroud was never in my i3MK/3s kit, outhewise I would have put it on.

Funny, no one made a comment about my comment about the Temple of Doom.

Senior Life member of IEEE.

Posted : 16/07/2022 3:08 pm
Diem
 Diem
(@diem)
Illustrious Member

Funny, no one made a comment about my comment about the Temple of Doom.

Always wise to stay clear of religion and politics.

Cheerio,

Posted : 16/07/2022 3:15 pm
Steve
(@steve-4)
Estimable Member
Topic starter answered:
RE: How do I keep PETG from building up on the hotend?

Nothing to do with either religion or politics.  It was a Harrison Ford thriller "Temple of Doom",.

Senior Life member of IEEE.

Posted : 16/07/2022 4:15 pm
Razor liked
Diem
 Diem
(@diem)
Illustrious Member

QED.  All religious references are misinterpreted.

Cheerio,

Posted : 16/07/2022 6:11 pm
Crab
 Crab
(@crab)
Reputable Member
RE:

Steps #43-45 in the assembly manual show the shroud and the fan connection.. did you assemble the kit?..  Likely it was there at one point .. was some of those "extra parts" one always has at the end.. 🙂 I think it is the only piece that is ABS (or ASA.. one of those) for the high temp.. don't use PETG.

Posted by: @steve-7

This fan shroud was never on there in the first place, which explains a lot.  I think I'll print another in case  I mess up this one.

Apparently, the fan shroud was never in my i3MK/3s kit, outhewise I would have put it on.

Funny, no one made a comment about my comment about the Temple of Doom.

 

Posted : 16/07/2022 8:07 pm
Steve
(@steve-4)
Estimable Member
Topic starter answered:
RE: How do I keep PETG from building up on the hotend?

I have to say that the shroud was NEVER in my kit, and i was a bit confused in assembling the hotend.  I printed the new shroud out of PC blend, which should withstand the heat.

I normally print PETG

The name of the movie of which I made the pun is "Indiana Jones and the Temple of Doom" released in 1984.

Senior Life member of IEEE.

Posted : 16/07/2022 9:31 pm
jsw
 jsw
(@jsw)
Famed Member
RE: How do I keep PETG from building up on the hotend?

If the shroud was not in your kit, did you notice that when the instructions said to mount it?

Posted : 17/07/2022 9:08 pm
Diem
 Diem
(@diem)
Illustrious Member
RE: How do I keep PETG from building up on the hotend?

You're lucky in that PETG needs very little fan but some filaments must have been tricky for you.

FWIW I got the film reference first time.  I simply chose to pick up on the Temple part ... perhaps I should learn to use more emojis.

Cheerio,

Posted : 18/07/2022 12:48 am
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