My printer originally has a hotbed equipped with a metal sheet with PEI paint with a rough finish, which can be removed from the hotbed and bent slightly to help release the part.
The sheet with PEI paint with a rough finish, for PLA works quite well and no additional measures are needed for the material to stick to the sheet, no lacquer, double-sided tape or glue is needed.
The sheet with PEI paint with a rough finish, for PETG also works, but it works too well, that is, the PETG adheres to the PEI more intensely than necessary and makes it difficult to remove the part from the sheet without risking breaking it. To solve the problem I got a metal sheet, made of common iron without paint, which is the one I use to print PETG, but on this sheet I do have to use an adhesion aid, specifically I use lacquer. Good luck.
FWIIW: I have used glass and PEI printbeds, PEI is excellent for PLA printing, but for PETG and the PC-ABS totally unusable since it appears to almost chemically bond.
A few years ago switched both my printers to Garolite (G-10 FR-4), and have not switched back. I print PLA, ABS, PETG and PC-ABS on it.
These are 1mm thick sheets, the one for my delta printer is glued to a steel disk that is magnetically clamped. On the other side is a sheet of 1mm PEI but that almost never gets used. I tend to also use hairspray with PETG and the PC-ABS since it helps the part release.
If you are unfamiliar with Garolite, it is actually the same material most PCBās are made from, and can be bought in many colors. I was able to get matt-black sheets for my delta printer; which works very well with itās IR level sensor.
Thanks a lot @artesanowallets! I think I need to get a PEI sheet probably as well, tried different things on tape with my PC plate, glue, hair spray (that was the funniest one!) etc. If didnāt work then probably will go with metal as you mentioned.
I think it should be something with the adjustments, because I printed auto-towers and a small part at the beginning (not great but I did). So, I think I need to recheck everything to see what I can do, or probably try to reprint the towers to see what is the problem. Thanks all
Once I got PETG dialed in, it was my go-to filament until I moved to enclosed printers and switched to ABS for most prints. But I did go through some frustration getting it dialed in! Some of that frustration is probably expressed in very old posts here on Maker Forumsā¦
Update: I did it! I printed the enclosure with PETG and looks fine! Yoohoo! Thanks a lot for all your help and advice everyone!
I did few changes in slicer settings:
The nozzle temp, used 245C instead of 230C or 235C. Noticed that the everything was fine with the first layer of the temp tower because started from 245C. So, thought might be better to increase nozzle temp to get better adhesion.
Decreased the bed temp to 75C from 80C or 85C.
Print speed100 mm/s, travel speed 250 mm/s, first layer print speed 15 mm/s, and first layer travel speed 120 mm/s. It was suggested that the combination of slower print speed with higher travel speed for the first layer can help with the adhesion.
Used painterās tape on bed, just wipe it down without any chemical, did set the nozzle temp and bed temp, and kept the enclosure closed for 30 minutes before starting the print.
After the leveling, put the auto-calibrated z-offset 0.01 far from the bed. The auto-leveling showed -1.75, then I adjust to -1.74.
I used brim for adhesion type instead of skirt.
Increased retraction distance from 4 to 5 mm and kept the retraction speed 40 mm/s.
Fan speed 40% and initial fan speed 0.
Not related to the first layer adhesion I think, but saw some recommendations that PETG is not doing great with Cubic infill pattern, so changed it to Triangles.
The result is ok, a side of the print was a bit off from the bed (about 0.6 mm), and I think the reason was the tape on that side. The tape was coming off on that side a bit!
I have a question, is that true that retraction distance should be 0.3 to 0.8 for direct drive extruder? When I chose Generic PLA in Cura by default retraction distance is 0.3 and if I do Generic PETG is 0.8. But if I chose eSUN PETG in cura by default the retraction distance changes to 3 mm. Just need to add that I am using Ender3 V3 SE.
I decided to look at the profiles Qidi set up for my (direct-drive) X-Max 3, which seems to have been decently tuned. It sets a 1mm retraction distance for the printer as a whole, and doesnāt override that in any of the filament profiles. I still get some fine stringing with many complex parts in both PETG and ABS, and just hit them briefly with a hot air gun. If you get heavy stringing with PETG, Iād start by drying the filament, because you might have microscopic steam bubbles continuing to push the filament through the nozzle even though you are retracting.
Thanks a lot @mcdanlj! All good, I just wanted to check with you. I got a comment that retraction distance of 4 or 5 mm is not correct for direct drive extruder. So, I ran auto-towers for retraction distance and speed and found that there is no obviouse difference between retraction distances, like now I am using 0.5 instead of 5 and all good. However, with more than 20 mm/s retraction speed I can see some stringing in the tower. Thanks a lot again for all your help!
Sorry, another question,
forgot to add that I didnāt find any light colour filament, so the only light colour that I could get it fast and cheaper was gray (By didnāt find, I meant something with a quick delivery and not too expensive). My plan is now to cover them with a silver or white paint spray (Rust-Oleum 2X ultra) and to give more UV protection, coated with Rust-Oleum 2X Ultra Cover Gloss Clear Spray Paint.
Do you think, does it help if I do a coating with Epoxy Resin first, then sprays? or just sprays should be fine?
Thanks
PETG has a low surface energy. This means that it doesnāt glue or paint as well as, say, PLA. I havenāt ever painted it. The advice Iāve seen for PETG is to sand it to create a physical binding layer, and to use primer first, and sand the primer.
I would expect epoxy resin to form a poor bond with the PETG and eventually peel. Iād skip that for PETG unless you find an account of it working well outdoors.
If you are lucky, the gray is some white (titanium dioxide) and some black (carbon) and not a dye. That would be better than colors, which are certainly dyes; many dyes bleach under UV exposure.
I have had a 0.7 mm piece of PEI on my printerās bed for the last 8 years. I print PETG, TPU, and ABS on it. I donāt print PLA, ever. TPU sticks pretty hard sometimes, but I find that putting a few drops of IPA at the base of the print before prying it loose will almost always get it to pop or peel right off. I usually wipe it with IPA before printing, but when I switch from TPU to other filament, I clean the bed by gently scrubbing it with a melamine sponge before wiping with IPA.
Thanks a lot for all your help and advice everyone!