Unresolved PETG warping on large parts.

I have been fighting with this since i got my printer and cannot figure it out. All of my large prints are pulling up on the corners a few hours into the print. Sucks to have a long job look good until 5 hours in. I've tried glue stick, different bed temps (60-85 degrees) I eventually used a sheet of PEI but it stuck too good and i couldn't get my last print off. Now i'm back to printing just on glass and i'm looking for some suggestions. There has to be a way! Here's a pic.

Thanks!

 

hmm i might have to try that. I might end up trying out PEI with gluestick too. I think i tried heating the bed up hotter but it seemed like it broke down the glue stick too much and just burned it off.

 

That wolfbite looks promising but it comes out to $30 shipped for a 2oz bottle. seems a little steep. I printed the last one with a 7 layer wide 2 tall Brim and it didn't have any effect on it warping from my last one. go with an even bigger brim? I think i'll try another piece of PEI tomorrow night with glue stick on that and see what happens.

 

Found it on Amazon for 19.99 free 2 day shipping so went ahead and ordered it from there. we'll see how well i can get it to work.

 

I should have it Tuesday to mess with all weekend. If it works then i really don't have a problem paying it. Now, does this for sure need heat to work? I'm still waiting on my new heaters to come in so right now i'm stuck with the 8"x8" stock heater on a 14" long bed. Do i even attempt to print something past the heated surface or should i just wait until i get my new heater? I'm tempted to try it but nothing is worse than a warped print i have to trash and try again. I already ruined a print yesterday morning that was 17 hours in by messing around with simplify3d and it crashing..

 

Yeah I was pretty pissed when it crashed, still had 10 hours to go. I thought i would be able to restart it from where it left off but it lost all my processes when it went down. I've never ran anything off the SD card because i always tweak my speeds once i get it running, so you can adjust the speed from the SD card? I didn't realize simplify could monitor a print like that. I'll have to give it a try. I've gone through 20+ spools of PETG and that was pretty much the only hiccup i've had software wise so i've just stuck with it.

 

Cool, that might be something to try eventually. I still haven't heard when my heaters will be here or if they've even shipped yet. Hopefully by the end of next week i'm hoping.

 

I have had good luck printing petg at 80c on the bed, as long as the first layer is good, never have problems with warping at all. I use esun brand. Start on your first two layers at 250-255c then drop it down to 245 on the 3rd layer, seems to give really good adhesion.
Waldo is right, the heating bed is not optimal and has a lot of dead spots, a new bigger heater would help prints from failing from warpage.

 

I have been printing the first two layers at 240 and dropping down to 235 after that. Also Esun PETG. I'm getting good results at 235 but maybe i'll try to bump up the first two a little bit higher. Bed around 80 and none of my parts lately have been sticking out past the heater. The wolfbite should be delivered today so i'll see how that does. I don't understand because one time i can have great results and the next it will warp up with the exact same settings. I had problems with it sticking too well printing straight on PEI but i have a couple more sheets to use so i might try to experiment with that after i try to print directly on my aluminum bed with wolfbite. So many variables.

It also seems to happen when my parts get past .75" tall or so. I can print short stuff with usually no problems but as soon as it gets taller it just pulls up off the bed.

 

I'll try something in vase mode tonight. I usually design everything i print with a radius where i know i will have a problem, i'm sure it helps a bit. My thought was that it always seemed like the more material it was laying down the more warping i would have. A lot of the stuff i print is 100% infill so there's a lot of filament heating and cooling at different levels above it causing it to pull up. Printing in vase will definitely give me an idea if that is the cause of the problem or not. I should be going home to a bottle of wolfbite so maybe that will solve all my problems forever.

 

Epic failure on the first test of wolfbite. Let the bed cool down and applying twice as much to give it another shot.