PETG, PLA, PEI steel sheet itps
I started printing everything with PLA. When I started testing PETG I followed the instruction manual guidelines and wiped the PEI with Windex (original) before each print. This worked well, good adhesion and easy to remove the print. FYI I have the rough finish PEI steel sheet, not the smooth sheet.
When I switched back to PLA I had huge adhesion issues which turned out to be from the Windex, Isopropyl alcohol did not work nor did rinsing with Dawn dish detergent (great for PLA). Finally I used Acetone and that did the trick - no more PLA adhesion problems. BUT, it seems there is an issue where too much use of PLA can eventually damage the PEI by making it too brittle.
Here are my tips:
1. Acetone works to clean off Windex.
2. Dedicate one side of the PEI steel sheet to PLA, and the other to PETG and don't use acetone. Use Windex on the PETG side and Dawn or alcohol on the PLA side.
I am neither a chemist nor a materials expert so if I have suggested anything that is not good please reply.
Re: PETG, PLA, PEI steel sheet itps
Your results may vary but I print PETG directly onto the PEI after it has been freshly cleaned with alcohol. I tried Windex but I got zero adhesion using Windex. I've never come across an issue where PETG stuck too well to the powder coated or stickered PEI sheets.
I did have an issue where I did not use a separation layer when printing ABS and ABS stuck too well to the sheet, causing the PEI to rip off. Go figure...
Edit: I do think it's critical to change your Z offset when you switch between PLA and PETG printing directly onto PEI. I raise my Z offset slightly because I found that PETG flows more and squishes more than PLA. Usually raising it by .010 or .005 works well enough for me.
Re: PETG, PLA, PEI steel sheet itps
Thanks for your comment and I agree about changing the Z to get the right squish.
Many of my prints cover the entire plate so I was concerned about over-adhesion as my small test pieces, with the Windex, seemed stickier than PLA Maybe baby powder is a better solution, at least it will smell better. FWIW the Windex I used was 'Original Windex' and there are lots of flavors with different chemicals.
I wish 3D printing was more developed with less trial and error and 'dialing in" but that is where we are at the moment. I bought the Prusa because Prusa uses them 24x7 in production. When everything is working on mine I do 20 - 30 hour prints without too many worries so I am very happy about that aspect of the printers - as well as the automatic bed leveling.
Re: PETG, PLA, PEI steel sheet itps
I second printing direct onto the textured PEI surface with PETG, just clean with alcohol. But I do adjust my Z offset to 0.025
When finished printing, I just take the still hot sheet and place it on a cold flat surface and wait a few minutes. The parts usually just pop off.
Normal people believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet.