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Blob half way my print, how can I avoid this?  

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Bas
 Bas
(@bas)
Trusted Member
Blob half way my print, how can I avoid this?

Hi, 

My Prusa stopped by its automatic crash detection (luckily) due to a blob half way the print. What can be the cause? And how can I avoid this? I am printing with PETG. I have a pre-assembled MK3S. Cheers, Bas

Best Answer by Bas:

I lowered the speed of support material from the default for PETG of 50 mm/s to 25 mm/s. This does the job! Extrusion multiplier set back to 1.

And I changed to the settings of '0.15mm QUALITY MK3' instead of '0.20mm QUALITY MK3'. But I did not test the difference with this lower support material speed.

Posted : 26/02/2020 6:50 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Blob half way my print, how can I avoid this?

Could you try reducing your extrusion multiplier to say 0.95?when the nozzle is pushing filament out of the way, some of the plastic collects on the outside of the nozzle, and when the collection gets big enough it drops off, onto your print usually in the most inopportune place... often causing collisions... 
slight under extrusion is less of an issue than over extrusion. 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 27/02/2020 5:17 am
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

Thanks Joan, I will try and come back.

Posted : 27/02/2020 7:51 am
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

Hi,

The new testprint with 0.95 extrusion multiplier is running.

I have made a few more photo's of my last failed print. The rectangle supports do not look quit nice. Has this to do with the same problem, e.g. over extrusion? See below pictures. (The print itself looks nice).

  • I am printing with PETG from HotOrange3D.
  • I am using the generalPET settings of prusa-slicer with 0.20mm QUALITY MK3.
  • Don't support bridges OFF
  • Printer is housed in a box with a temperature between 30 and 34 degrees Celcius.

Thanks on advance

Bas

This post was modified 4 years ago by Bas
Posted : 27/02/2020 9:02 am
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Blob half way my print, how can I avoid this?

@basbasbas

Hi Bas, 
How is the new print going?

 

Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 27/02/2020 9:25 am
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

Hi Joan,

Here is a photo of the print running:

Posted : 27/02/2020 10:09 am
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

So far so good. A tiny bit of filament collected around the nozzle. I removed this bit and resumed the print.

Posted : 27/02/2020 12:22 pm
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

Hi,

Some first drops off filament occur now on the support. What to do?

Posted : 27/02/2020 12:53 pm
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

attached is the gcode

Posted : 27/02/2020 12:56 pm
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

attached is the gcode

Posted : 27/02/2020 12:57 pm
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

The first layer of the support has started:

Posted : 27/02/2020 1:11 pm
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

Hi Joan,

The second layer of the support started and looks very messy. I pauze the pint now to wait for your (or someone else his or her) response.

 

Posted : 27/02/2020 1:18 pm
Bas
 Bas
(@bas)
Trusted Member
Topic starter answered:
RE: Blob half way my print, how can I avoid this?

I lowered the speed of support material from the default for PETG of 50 mm/s to 25 mm/s. This does the job! Extrusion multiplier set back to 1.

And I changed to the settings of '0.15mm QUALITY MK3' instead of '0.20mm QUALITY MK3'. But I did not test the difference with this lower support material speed.

This post was modified 4 years ago by Bas
Posted : 01/03/2020 12:06 pm
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