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PETG parts bend after print  

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McAce
(@mcace)
New Member
PETG parts bend after print

Hey everyone,

 

I have encountered a problem with bending parts after I removed them from the printbed/sheet. (see pic)

When I put the part back on the warm heated bed and apply a little bit of force to the top the parts are straight again. When they cool down, they bend. So it seems there is a lot of tension in the part. 

Do you have some suggestions how I can fix this problem?

 

The parts have the following dimensions: 180/180/10 (x/y/z)

 

Here is some data to material and print:

 

Material: Das Filament PETG white

Layers: 0.2mm

Temps: 230C nozzle, 85C bed

4 bottom layers, 5 top layers, 2 perimeters. 10% infill rectiliniear

 

 

Greetings Kristian

Opublikowany : 28/09/2019 2:43 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: PETG parts bend after print

I tend to use gyroid infill, and either octogram spiral or Hilbert curve for top and bottom layers
these infills have disrupted lines which are less likely to shrink and tighten on cooling.

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

Opublikowany : 28/09/2019 3:46 pm
Sembazuru
(@sembazuru)
Prominent Member
RE: PETG parts bend after print

I discovered the hilbert curve bottom layer fill can create some neat optical effects with some filaments (at least with smooth PEI build sheets). I first discovered this with the Prusa (Filament PM) Silver that came with my printer. Because of all the right angles I get a nifty almost holographic effect with a surface that feels smooth.

See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs

Opublikowany : 01/10/2019 3:37 am
McAce
(@mcace)
New Member
Topic starter answered:
RE: PETG parts bend after print

Sorry for my late reply! Thank you for your suggestions. 

I gave it a try with the gyroid-infill and the octogram spiral for bottom and top layers. The parts still deform after removing from the sheet. 

I'm going to do some testprints with different layernumbers for top and bottom. I will also try a different PETG-brand. 

I will let you know, what I found out. 

Opublikowany : 07/10/2019 2:27 pm
jwvaughn
(@jwvaughn)
Estimable Member
RE: PETG parts bend after print

I've had problems with PEGT bending, especially bigger parts,  when I remove them from the build plate before they have cooled to room temperature. My guess is that the PETG is still soft and when I bend the plate to remove them they bend and stay that way.

Just a thought...

Jerry

Opublikowany : 07/10/2019 3:28 pm
cwbullet
(@cwbullet)
Member
RE: PETG parts bend after print

You have to let them fully cool.  If they are still flexible, it might have under extrusion.  

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

Opublikowany : 07/10/2019 3:29 pm
McAce
(@mcace)
New Member
Topic starter answered:
RE: PETG parts bend after print
Posted by: @jerry-v2

I've had problems with PEGT bending, especially bigger parts,  when I remove them from the build plate before they have cooled to room temperature. My guess is that the PETG is still soft and when I bend the plate to remove them they bend and stay that way.

Just a thought...

Jerry

Good thought, I had the same. 🙂 The part on the pic above cooled for hours. 

Opublikowany : 07/10/2019 3:58 pm
McAce
(@mcace)
New Member
Topic starter answered:
RE: PETG parts bend after print

 

 

First test prints are done. At 65°C bed temp the problem seems to be solved. 

Opublikowany : 07/10/2019 4:35 pm
jwvaughn
(@jwvaughn)
Estimable Member
RE: PETG parts bend after print

Good to know!  Another trick ot add to my bag of tricks 😊 

Jerry

Opublikowany : 07/10/2019 6:31 pm
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