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Suddenly very hairy print  

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bvolckae
(@bvolckae)
Active Member
Suddenly very hairy print

Hello all,

doing my first prints, which came out OK (using Spruzaslicer, a MK3S with grey Prusa PLA). Then I printed something with a bit more vertical detail and it became like a cobweb (the aim was to print grass patches for a board game). Is this something I am doing wrong? Settings are up-to-date for Prusa PLA, printed at 0.1MM. Printer is located in an office with no draft or so (temperature is stable).

Thanks for any pointers.

Best regards,

Bruno

Posted : 25/12/2021 9:17 am
cwbullet
(@cwbullet)
Member
RE: Suddenly very hairy print

It looks like you could have two issues - hydrated filament and / or poor extrusion.  Have you tried a different roll of filament?  

--------------------
Chuck H
3D Printer Review Blog

Posted : 26/12/2021 1:24 am
bvolckae
(@bvolckae)
Active Member
Topic starter answered:
RE: Suddenly very hairy print

I tried it with a Prusament PETG filament spool and it was nearly the same result. How would I check / fix poor extrusion? The printer was bought assembled, not as a kit, so I have a little less feeling with how to disassemble the nozzle for instance.

 
Posted : 26/12/2021 6:54 am
Diem
 Diem
(@diem)
Illustrious Member
RE: Suddenly very hairy print

Have you tried 0.15 or 0.2mm layers?  If this terrain is to be painted it will make little difference and stringing problems should be fewer.

I agree with @cwbullet, damp filament is a probable underlying cause. It has been a major problem for many users this year.  Search for drying filament elsewhere on here.

Moisture in the hotend boils and messes with the extrusion pressures so I wouldn't make drastic changes until I had tried drying first.

Posted : 26/12/2021 8:49 am
cwbullet
(@cwbullet)
Member
RE: Suddenly very hairy print

Like said above, I would try o.2 layer height first before we consider the other possible cause of poor extrusion.  

Posted by: @bvolckae

I tried it with a Prusament PETG filament spool and it was nearly the same result. How would I check / fix poor extrusion? The printer was bought assembled, not as a kit, so I have a little less feeling with how to disassemble the nozzle for instance.

 

 

--------------------
Chuck H
3D Printer Review Blog

Posted : 26/12/2021 10:57 am
bvolckae
(@bvolckae)
Active Member
Topic starter answered:
RE: Suddenly very hairy print

finishing a 0.15 print (mostly horizontal things), without spotting hairy cobwebs. Will try a 0.2 print of the one that caused issues (with lots of vertical extensions) after that one and report back.

 
Posted : 26/12/2021 1:02 pm
bvolckae
(@bvolckae)
Active Member
Topic starter answered:
RE: Suddenly very hairy print

the left one is the 0.2mm print, the right one the original I posted in my initial post. The problem is still quite there, but less so than in the original print. Any advice on what to do? Or is this something I should not attempt to fix (first 3d printer for me, so not entirely sure what to expect).

 
Posted : 27/12/2021 3:44 pm
Henry
(@henry-2)
Estimable Member
RE:

This is something that is quite within the realm of being possible to improve. I just went through this process with Atomic Filament's Deep Black PETG. I don't know how much of this will apply to PLA. I used this model for this testing: https://www.prusaprinters.org/prints/979-retraction-test

From the BOTTOM to the TOP:

  1. Generic PETG settings
  2. Increased retraction to 2mm
  3. Reduced retraction to 1.4mm and set "Retract amount before wipe to 50%"
  4. Ran the filament through the dehydrator

Not pictured, but I further improved the hairiness by setting the retraction speed to 25mm/sec. I think the default is 35mm/sec

 

Posted : 27/12/2021 5:23 pm
Diem
 Diem
(@diem)
Illustrious Member

That still looks like damp filament.

With multiple fine points like those you will never completely eliminate stringing but you should b able to get it to a level where a quick wave with a heat gun clears it up.

Cheerio,

Posted : 27/12/2021 11:15 pm
bvolckae
(@bvolckae)
Active Member
Topic starter answered:
RE: Suddenly very hairy print

Since damp filament has been mentioned a few times: the filament I'm using is a day or 5 out of the box (as it arrived straight from Prusa with my printer). That means it could be damp on arrival so to speak? It was unboxed (undone of plastic wrap) and just put on my printer (and I have been printing daily since then).

 
Posted : 28/12/2021 7:19 am
3Delight
(@3delight)
Moderator Moderator
RE: Suddenly very hairy print

If you rule out damp filament then try lowering the hot-end temperature a few degrees and see if that helps. It has for me in the past.

Posted : 28/12/2021 4:08 pm
Diem
 Diem
(@diem)
Illustrious Member
RE: Suddenly very hairy print

the filament I'm using is a day or 5 out of the box

Thomas Sanladerer tests filament drying:

    

After a week exposed in a room with a dehumidifier running there was noticeable deterioration of PLA finish...

Cheerio,

Posted : 28/12/2021 7:25 pm
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