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SteveS
(@steves)
Trusted Member
Warped PETG?

Just printed off parts for the Lack Enclosure and noted that they seem warped. First prints that have done this. Huge amount of time and filament to realise this 🙁

 

Thoughts as to why it should have done this? Haven't noticed it on any other prints but then again they haven't been such "long" prints i.e. across the heat bed.

This topic was modified 3 years ago by SteveS
Posted : 10/10/2020 11:55 am
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(@)
Illustrious Member
RE: Warped PETG?

In general, for large pieces, you need to increase the heat bed temps after the first few layers are down, reduce the cooling fan speeds and perhaps use a full height skirt to keep the upper layers of plastic as warm as possible.  

One other method that can help is to place the printer in a large cardboard box for the print - simulate your enclosure environment. 

Posted : 10/10/2020 6:41 pm
jsw
 jsw
(@jsw)
Famed Member
RE: Warped PETG?

I would suggest two things.

One, use the 'draft shield' option in your slicer.  Both PrusaSlicer and Cura have it.  This will give you a 'mini-enclosure' around your piece and help to keep the temperature stable.

Two, use some kind of adhesion helper.  Glue stick will certainly work.  I've been using the product below, Layerneer Bed Weld, and for large flat prints I'm in the habit of putting a dab of it where the corners/edges of the print will be to prevent curling and separation.  (Regular users are probably getting sick of me plugging this product, but I've found that it really works, both as an adhesion helper and a release agent.)

Posted : 11/10/2020 1:27 am
SteveS
(@steves)
Trusted Member
Topic starter answered:
RE: Warped PETG?

I've defaulted to the Prusa settings for the Lack parts except for the Contact Z distance for support. Also chopped down the files for each print so instead of three large parts over most of a day, slice a single part.

First couple of parts came out fine. Possibly timing between getting from one part to the other? Possibly environmental? Prints were run overnight so maybe the ambient dropped a little low? Now I'm printing through the day instead. 

Posted : 11/10/2020 9:56 am
cwbullet
(@cwbullet)
Member
RE: Warped PETG?
Posted by: @stev-19

Just printed off parts for the Lack Enclosure and noted that they seem warped. First prints that have done this. Huge amount of time and filament to realise this 🙁

 

Thoughts as to why it should have done this? Haven't noticed it on any other prints but then again they haven't been such "long" prints i.e. across the heat bed.

It happens on occasion.  An enclosure or draft shield will reduce the odds significantly.  

As @jsw said, you can use an adhesion promoter.  I use three different ones regularly with good success.  I use a glue stick, Layerneer Bed Weld, or Aquanet Hair Spray.  I use Aquanet for most filaments and reserve the Layerneer for ABS.  I find that Aquanet works well for PETG and PLA.  I need a little more for ABS so I use Layerneer.  Glue Stick is what I use for PC and PC Blend.  It protects the bed from over adhesion while promoting adhesion.  The weakness with glue stick is the need to clean the print.   

If you are not in the US, I can find similar products in Europe.  

 

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

Posted : 11/10/2020 12:58 pm
Peter M
(@peter-m)
Noble Member
RE: Warped PETG?

And a clean bed will help, clean the bed with dish soap.

First layer needs to be 100%.

Both settings are for good sticking to the bed.

-Normally with big flat parts I use glue stick.

-Keep cold are away from printer

-extra normally not needed:

First layer hotter,

first layer slower.

 

Posted : 11/10/2020 4:22 pm
SteveS
(@steves)
Trusted Member
Topic starter answered:
RE: Warped PETG?

Cheers for all the comments guys. 

As said, stuck to the Prusa settings for the Lack enclosure parts except the Z offset for support. Re-slliced their files such that I am only printing one large object at a time and ..... fingers crossed. getting really good prints. No odd lines (layer shift?) no stringing, nice finish.

Also means I don't have to wait all day to see how they turn out. Print one, check. onto the next.

Posted : 11/10/2020 7:54 pm
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mjlewis37
(@mjlewis37)
Trusted Member
RE: Warped PETG?

Perhaps another consideration, is your PETG wet?

The last few days my small PETG parts were warping and printing poorly. Turned out to be moist filament. 4 hours at 60C seems to have fixed it.

Are you getting a smooth steady stream of filamant when you do a load filament?

Posted : 19/10/2020 5:01 pm
SteveS
(@steves)
Trusted Member
Topic starter answered:
RE: Warped PETG?

@mike-l14

House is generally pretty warm and there's none of those nasty radiator humidifiers in this room 🙂

As said. printing has been great lately since I cut the printing down into smaller chunks. 

Posted : 19/10/2020 7:52 pm
mjlewis37
(@mjlewis37)
Trusted Member
RE: Warped PETG?

@stev-19

Good, just throwing the possibility of wet filament out there for other folks to consider when looking at your thread.

You said were getting other good prints, so I did doubted that was your problem.

I wasn't aware PETG warped. I'm sure I'll be refering to your thread in the future. 🙂 

Posted : 19/10/2020 11:03 pm
cwbullet
(@cwbullet)
Member
RE: Warped PETG?

@mike-l14

Always possible.  

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

Posted : 19/10/2020 11:24 pm
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