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Rimantas
(@rimantas)
Member
Stringing

Hi!  I decided to open up a brand new spool of  prusa petg for an upcoming project, but my test prints have been very stringy.  I’ve tried changing a few settings, but don’t see much of a difference.

 from left to right…

1. All default settings (0.8mm retraction length, 250C hotend temp, 35mm/s retract speed)

2. 1.0mm retract length

 3. 1.5mm retract length

 4. 240C hotend temp

 5. 70mm/s retract speed

printer is MK3S kit, filament is prusament petg anthracite grey.

Can anyone suggest some other settings to try changing? Something that has worked for you maybe?

 Thanks in advance!

 Rimantas

Best Answer by Crab:

I print most of my PETG (not Prusa) at between 220-230 .. try a big change like 225 and see what happens. You don't want it so cool it has no strength, but one variable to try.

 

Posted : 21/11/2023 5:00 am
JimB
 JimB
(@jimb)
Estimable Member
RE: Stringing

Try drying it before anything else.  Just because it is new doesn't mean it hasn't taken up moisture (either before or after being packaged).

Posted : 21/11/2023 12:50 pm
Crab
 Crab
(@crab)
Reputable Member
RE: Stringing

I print most of my PETG (not Prusa) at between 220-230 .. try a big change like 225 and see what happens. You don't want it so cool it has no strength, but one variable to try.

 

Posted : 21/11/2023 1:03 pm
Rimantas
(@rimantas)
Member
Topic starter answered:
RE: Stringing

I wouldn't think that moisture is an issue in this case because the spool was in a sealed bag with a beefy desiccant pack.  I also live in a relatively dry climate (it's currently 10%RH indoors)

Posted : 21/11/2023 4:52 pm
Rimantas
(@rimantas)
Member
Topic starter answered:
RE:

Printing at 225C seemed to do the trick. I wonder why this flavor of petg has a recommended nozzle temp of 250C +/- 10C.

The test part's strength seems to be acceptable as well.

This post was modified 1 year ago by Rimantas
Posted : 21/11/2023 5:26 pm
Diem
 Diem
(@diem)
Illustrious Member

because the spool was in a sealed bag with a beefy desiccant pack.

All the manufacturers try hard but you have no idea how long it was stored in the warehouse or how it was treated in transit ... a deck stacked container at sea can rise and fall by 30°C daily alternately sucking in and blowing out moist sea air...  you get the idea.

Always suspect dampness first when stringing occurs, your first picture looks typical.

Cheerio,

Posted : 21/11/2023 5:48 pm
Robin_13
(@robin_13)
Reputable Member
RE: Stringing

New to 3D printing, I have read and read and read.  One of the common points is to never trust new filament to be what the last roll was like.  Even the same brand and manufacturer.  Always do some test prints to confirm settings.  I am at the phase in my learning to try to come up with a decent procedure for this.  Always assume that it is not dry, even when stored with desiccant.  I have found that most colour changing desiccant will start to change colour at the upper limit of filament RH%.

If you live in a dry environment, then leave the filament out for a few days and test.  Make sure your humidity stays dry for the full time.  I know mine shoots up at night.

 

Posted : 26/11/2023 4:58 am
Rimantas
(@rimantas)
Member
Topic starter answered:
RE: Stringing

I currently don't have any way to dry filament besides an oven, which I've read isn't the best tool for the job.  I'll have to put together one of those desiccant-filled filament storage tubs.  Thanks for the feedback!

Posted : 27/11/2023 5:47 pm
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