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PETG - fat loop and elephants foot  

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John
 John
(@john-6)
Reputable Member
PETG - fat loop and elephants foot

Recently been trying PETG (Prusament) and have found that I am getting a large elephant's foot even on a shallow print. I have already filed it off so I dont have a photo. I also notice a single loop is double wide ie 1.28 mm with a 0.6mm nozzle. I get the same result with a first layer calibration.

As far as I can tell the Live Z is good and the item prints well aside from the elephant's foot. 

Attached is photo of 20mm cube in vase mode - upside down you can just see the elephants foots in top left corner.

Print size

  1. 19.9w x 19.9d x 19.7h - so height is a bit low
  2. wall thickness 0.6mm
  3. I meant to turn off elephant compensation which is at 0.5mm but it is is still about 0.13mm
  4. Loop width 1.28mm. Thickness 0.2mm

I'm using the prusament PETG preset with 0.6mm nozzle preset and 0.2mm layers on Geckotek hot with windex added

If I raise the Live Z the filament starts to not stick

BTW how do you add multiple photos in one go?

 

Best Answer by John:

I think I have the answer.

I bumped the 1st layer nozzle temp to 250 up from 240 (as mentioned I am using a hardened steel one).  This made the filament stick better and was able to raise the live Z value. The temp issue was also compounded in the first layer calc which sets PETG at 130. I was using the first layer calc to get a rough z height before using a larger square. I did forget to mention the sheet with gecktek was new.

No elephants foot and cube dimensions pretty well spot on

i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]

Posted : 02/06/2021 6:09 am
Neophyl
(@neophyl)
Illustrious Member
RE: PETG - fat loop and elephants foot

For proper help you need to save your project from within slicer (File>save project as) and take the resulting 3mf file, zip it into an archive and then attach it.  That will then contain not only the model but all your settings, anything custom etc.  Basically its a snapshot of your setup.  With it we can check all sorts of things.

As for the 'fatloop' well there is a setting for minimum extrusion on the skirt, on small models this will cause more than 1 loop as it fulfils the min extrusion filament setting.

If we had your project file we could see what your configured first layer height and normal layer height is set to.  Sometimes if the combination doesn't add up then there can be a height difference.  For example IF you has a 0.2mm first layer but were using 0.4 layers for the rest of the print then that would add up to 19.8 or 20.2.  So you wouldn't get a perfect height.  I'm not saying you have but thats an example.  Normally you would just add a bit of variable layer height to get the layers to align perfectly.

You can attach multiple pictures using the Add Media button.  That allows you to add pictures to your accounts gallery and then you can include them in the post.  It also allows you to set other parameters like picture size (so you can display it inline smaller and click to see full size) etc.

 

Posted : 02/06/2021 9:18 am
John
 John
(@john-6)
Reputable Member
Topic starter answered:
RE: PETG - fat loop and elephants foot

Here we go

 

Attachment removed

i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]

Posted : 02/06/2021 9:50 am
Neophyl
(@neophyl)
Illustrious Member
RE: PETG - fat loop and elephants foot

Looking at that project if you are getting that much squish on the first layer and the loop then it pretty much has to be physical, down to your printer bed adjustment.

Posted : 02/06/2021 11:16 am
John
 John
(@john-6)
Reputable Member
Topic starter answered:
RE: PETG - fat loop and elephants foot

It is not happening with my PEI sheet and PLA so it is probably the geckotek sheet. When you say bed adjustment what are you suggesting. 

i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]

Posted : 02/06/2021 8:44 pm
John
 John
(@john-6)
Reputable Member
Topic starter answered:
RE: PETG - fat loop and elephants foot

Just to confirm the first layer and loop is printing at 0.2mm thick

i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]

Posted : 02/06/2021 9:56 pm
John
 John
(@john-6)
Reputable Member
Topic starter answered:
RE: PETG - fat loop and elephants foot

I think I have the answer.

I bumped the 1st layer nozzle temp to 250 up from 240 (as mentioned I am using a hardened steel one).  This made the filament stick better and was able to raise the live Z value. The temp issue was also compounded in the first layer calc which sets PETG at 130. I was using the first layer calc to get a rough z height before using a larger square. I did forget to mention the sheet with gecktek was new.

No elephants foot and cube dimensions pretty well spot on

i3 Mk3 [aug 2018] upgrade>>> i3MK3/S+[Dec 2023]

Posted : 03/06/2021 2:33 am
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