"Fungi" and "Blobs" on otherwise perfect surface prints
 
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"Fungi" and "Blobs" on otherwise perfect surface prints  

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Durahl
(@durahl)
Trusted Member
"Fungi" and "Blobs" on otherwise perfect surface prints

Greetings!

I've recently started experimenting with CF-Nylon and, after some initial Bed Adhesion issues on the PEI ( Sticky Glue FTW ) and consistent dimensional inaccuracy ( Extrusion Multiplier changed from 1.04 to 0.7 ) one of the last challenges I've come across would be those "fungi" and "zits" appearing around the surface regardless of seam positioning.

Photos:

Video:

Slicer Extruder Settings:

Simple shapes like a Calibration Cube sure are printing flawless but anything requiring the toolhead to cross a gap has these issues... Is this perhaps a Retraction related issue or simply the nature of the material with the ~20% CF content smearing along as the nozzle crosses borders? 🤔

Posted : 15/09/2021 8:09 pm
cwbullet
(@cwbullet)
Illustrious Member
RE: Filament

Did you dry your filament? Nylon soaks up water.

--------------------
Chuck H
3D Printer Review Blog...
Posted : 16/09/2021 10:30 am
Durahl
(@durahl)
Trusted Member
Topic starter answered:
I'd say I did

Sure did, the spool has been permanently residing in an eSUN eBox Filament Drying Box set to max Temp ( 50°C ) incl. a Dessicant Pouch before and during the prints 🤔

Posted : 16/09/2021 10:46 am
cwbullet
(@cwbullet)
Illustrious Member
Extrusion

Try lowering the Extrusion multiplier one more to 0.6 and see what happens.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 16/09/2021 10:50 am
Swiss_Cheese
(@swiss_cheese)
Noble Member

eSUN eBox Filament Drying Box set to max Temp ( 50°C )

This is not adequate, you need 70C active drying, meaning 350watts minimum with a strong active fan circulating. run it the entire time your printing the nylon.

 

Good Luck

 

Swiss_Cheese

The Filament Whisperer...
Posted : 16/09/2021 2:14 pm
cwbullet
(@cwbullet)
Illustrious Member
RE: Drying

I just read this again from work.  I agree with Swiss Cheese.

The bottom line, is you need more time and at least 70C if not 80C.  

Posted by: @durahl

Sure did, the spool has been permanently residing in an eSUN eBox Filament Drying Box set to max Temp ( 50°C ) incl. a Dessicant Pouch before and during the prints 🤔

 

--------------------
Chuck H
3D Printer Review Blog...
Posted : 16/09/2021 2:33 pm
Durahl
(@durahl)
Trusted Member
Topic starter answered:
Yeaa...

There's not much I can do about raising the temps in that enclosure.

I mean the manual states that the built in heater plate raises the temps to 80°C with expected actual temperatures getting circulated by the also built in (and super noisy fan ) in the 50°C but yea... Can't raise it higher than that 🤔 The Spool also arrived inflated ( or at least without a vacuum ) indicating the presence of untreated air inside but a lengthy treatment inside the dryer probably dealt with most moisture that managed to get inside.

I did though in the meantime play around with retraction settings ( like increasing them to 5mm, enabling wipe, etc... ) and reducing the temperatures back to 260°C from the previous 270° due to the higher speeds at which I'm printing while also increasing the cooling fan % and it looks like those changes were helping a fair bit with solving the problem. 🙂

Posted : 16/09/2021 3:02 pm
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