Printing with PETG  

Page 1 / 2
  RSS
jluvs2ride
(@jluvs2ride)
Active Member

New guy here.

I've printed several projects very successfully using the PLA that came with my printer. I've tried printing a project that calls for PETG using the PRUSA PETG in black but it doesn't seem to be going very well. I selected the PRUSA PETG when I sliced the model but the bed adhesion seems poor. 

Should I have re-calibrated the first layer? Are there other considerations I may need to consider outside of selecting the PETG profile in the slicer?

Regards.

Posted : 21/01/2021 6:23 pm
fuchsr
(@fuchsr)
Reputable Member

Re-doing live Z can't hurt, in my hands it's rarely needed when I switch between PLA and PETG. The stock Prusament PETG profile does a fine job for me. It shouldn't take more than a really clean bed to stick and proper Live Z to stick. 

Posted : 21/01/2021 9:18 pm
jluvs2ride
(@jluvs2ride)
Active Member

@fuchsr

Just finished a five hour print. It seems that the support material didn't really bind to the first layer which seems to have decent adhesion to the plate.

Posted : 21/01/2021 10:19 pm
Swiss_Cheese
(@swiss_cheese)
Reputable Member

what kind of bed are you working with? can you show us pictures of the problem? can you post a zipped up.3MF project file?

Posted : 21/01/2021 11:41 pm
cwbullet
(@cwbullet)
Illustrious Member

Post your first layer results.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 22/01/2021 12:54 am
jluvs2ride
(@jluvs2ride)
Active Member

Thank you all for responding. I'm printing on the PRUSA Steel Sheet. This particular project I printed a couple of times using PLA with great results. Using the PETG it seems the first layer had good adhesion of the support material to the sheet but the next layer or so did not adhere well to the first layer.

I'd like to print this project using a finer resolution.

The attached photo shows the first layer of the support material on the sheet.

Posted : 22/01/2021 11:44 am
Dan Rogers
(@dan-rogers)
Estimable Member

I know that picture ... happens sometimes.  Here's what I think

1.  Don't use the steel sheet for PETG.  Use the textured sheet.  You'll thank me later ($$$)

2. Brim.  Add a few millimeter brim to your part, and re-slice.  It'll help keep things from going south when the interface lines go a little dodgy.

3.  Speed.  Slow down your speed a bit.

Those very little lines are the interface lines that will be laid down before supports get laid down.  They are very fragile, and tend to melt when the hot head gets near them again.  If your nozzle is dragging frass, it'll interfere with printing the interface lines, or push them like a snowplow as it tries to lay the first layer of the support structure (interface always precedes support structure - by obsesrvation)

Posted : 22/01/2021 4:12 pm
Swiss_Cheese
(@swiss_cheese)
Reputable Member

it looks like your Z is to high and needs to be lowered a bit. its fine to use PETG on textured sheet just spray with original Windex first.

This post was modified 2 months ago by Swiss_Cheese
Posted : 22/01/2021 4:16 pm
cwbullet
(@cwbullet)
Illustrious Member

@jluvs2ride

Z is definitely too high.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 22/01/2021 4:26 pm
fuchsr
(@fuchsr)
Reputable Member

I agree with @swiss_cheese. I don’t see a reason why you shouldn’t get great results with PETG on the smooth sheet. I used it all the time before I switched my printers to the BCZAMD textured sheet , which in my hands works great for any filament I’ve tried. If live z adjustment and a good cleaning of the sheet doesn’t help, I’d try a brim or a thin layer of Layerneer bed weld. 

Posted : 22/01/2021 4:33 pm
Dan Rogers
(@dan-rogers)
Estimable Member

I'm just gun-shy after destroying three sides on two smooth sheets with PETG - before I learned about the windex trick.

Posted : 22/01/2021 5:20 pm
jluvs2ride
(@jluvs2ride)
Active Member

I wanted to print this at a finer resolution so I resliced the original file at 0.1, cleaned the bed and the printing seems to be going as it should.

Thank you all for your assistance and suggestions. I will let you know how this goes.

Posted : 22/01/2021 7:25 pm
jluvs2ride
(@jluvs2ride)
Active Member

Would the Z calibration be different for a different filament material?

Posted : 22/01/2021 7:26 pm
cwbullet
(@cwbullet)
Illustrious Member

@jluvs2ride

It absolutely can be.  I have had several material that are less adhesive and required more squish.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 22/01/2021 7:31 pm
cwbullet
(@cwbullet)
Illustrious Member

@dan-rogers

The Windex trick is key.  I have found that hair spray also works.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 22/01/2021 7:34 pm
jluvs2ride
(@jluvs2ride)
Active Member

@cwbullet

I have been scrupulous about cleaning the bed using a microfiber cloth and 97% isopropyl alcohol before and after prints.

So if I use Windex, do I want to leave some residue or follow with a cloth dampened with clean water?

Posted : 22/01/2021 9:40 pm
sbto
 sbto
(@sbto)
New Member

My understanding is that Windex leaves a slight residue which prevents PETG from adhering to the point of pulling chunks out of the PEI sheet. So no, you should not further clean it off after applying.

Posted : 22/01/2021 10:20 pm
Dan Rogers
(@dan-rogers)
Estimable Member

<swallows, loosens collar with one finger>

So, I have some fishing spoons to print this weekend (3 color PETG) - and I've a fresh smooth PEI sheet in reserve - I'll do the windex trick on my last good print surface on my battle sheet.

Posted : 22/01/2021 11:17 pm
Swiss_Cheese
(@swiss_cheese)
Reputable Member

BTW, I did mean to say smooth sheet not textured, thank you fuchsr.

Posted : 23/01/2021 2:29 am
cwbullet
(@cwbullet)
Illustrious Member

Good luck.  No matter which sheet you choose Windex will reduce adhesion and promote separation with PETG.

--------------------
Chuck H
3D Printer Review Blog...
Posted : 23/01/2021 2:35 am
Page 1 / 2
Share:

Please Login or Register