ARGHHHh PETG bed adhesion problems

Okay, so yes I have printers that can print PETG with no problems on bed adhesion (my new TEVO tornado and the Anycubic i3 Mega with the Ultrabase and the Kossel Linear plus), but I like to torture myself and make all work. Right now the problem is my Cr-10, I tried glue stick, at 80 C and still warped on two sides, cleaned the bed fully and tried, same. Then without glue and glass higher temp even worse. Finally got Magigoo today and I thought that would make it better, but nooooooooo it started perfectly fine, but 1 hour into the print, the same freaking corner starts to warp up again. This is magigoo on the glass bed of the Cr-10 at 80 C first layer temp, then 78 C for the rest. Helpppppp xD Temp for the filament is 240C first layer, than 235C the rest, with fan cooling at 80% after first 2 layers.

In my only experience with PETG so far I had success with adhesion on glass with hairspray and no warping. But it was a relatively small part (my motorcycle turn signal mount). I think I printed it at 245C with bed temp 60C. Not sure about the fans and such, I just left that the default in the profile in S3D. But I don't recall if I used the PLA or ABS profile (S3D doesn't have a PETG profile for my printer). I used one of those and adjusted the temps. I had other issues with the part being weak and the surface being rough but I think that was because I bought a PETG filament with carbon fiber and it probably wasn't the best choice for a thin wall application.

which brand of PETG were you using? I'm using Hatchbox, I've been hearing some people say both sides. Some say 80+ C for bed, some say just 50-60 C is enough, guess I'll have to waste PETG to try. Oh yeah it's fine for less than 3 hour prints, but more than that >.< Will try when I get home today.

Mine is MatterHackers carbon fiber. I decided to try that when they were out of the plain black. I have one multi-hour project I'd like to do in regular PETG, a case for my Torrent drone and batteries. I made one out of PLA and it is OK... took like 12 hours to do the main box. I'll try that sometime when I get some regular PETG and see if it survives the process.

I am getting an Anycubic Ultrabase for my Anet a8 in a few days ,I read that they work reply well.Does it work as good as they say?

it'sr eally good. I'd have no trouble printing PETG on it on my i3 Mega.

Update on my PETG on Cr-10, still not working, i've tried from 60 to 80 C bed temp, still warps even with magigoo. However here's the interesting thing I've noticed, the one on the back is perfectly fine from 60-80 C, it's the one in the middle that warps, and it's just the front corners. So I'm really confused now, is that more of a nozzle issue or something?

Printed PEGT at 250C on 80C bed on Kapton. It is going to depend on the filament as to how well it prints. You could try something like hairspray. Also try and control the printing environment. An enclosed print space is best.

Wow, not sure whats going on with yours. I printed this lid for my Torrent drone case last night in PETG with carbon fiber, about a 5 1/2 hour print, about 6 x 7", no issues with adhesion or warping. Printed on my Klic N Print 3D, 250/60C temps, using Makerbot ABS profile in S3D, on glass table with hairspray.... see pic below.


Here is something that I coincidentally got in my e-mail yesterday that may help. It is a PETG how-to from MatterHackers that discusses build table materials, adhesion, temps, etc.

http://mailchi.mp/matterhackers/f1yk...9?e=4a193f004f




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Think I've only ever printed pet-g on printbite, which works great :-)

Bear in mind that pet-g bonds and warps less at the lower end of the prnting range. Unlike pla whcih works best at the upper range, pet-g is best printed as cool as you can get away with. Layer bonding will be better, and it will shrink less and stay stuck more.
And it doesn't like being printed at any kind of speed either.

So 50-60mm/s max and around 225-230c temp.
Currently I have esun pet-g & colorfabb xt (also pet-g).
Bed temp - around 70c seems to work well for me.
Never printed any large things with it, but the small items are really strong.

pet-g with carbon fibre will shrink less than standard pet-g as the carbon fibre has no noticeable expansion at that low a temperature (it's low for carbon).

I print PETG / T-Glase just like ABS: 240C head, 80C bed, hairspray.

Thanks for the help all, crossing my fingers right now, but I seem to have found the problem, the fan, totally forgot about it, it was at 85%, which is way too high, I have it a 0 C, 245 C and 80 C bed, layered perfectly. However, I do need the fan as the PETG parts has bridging, I am using supports, but do need a little bit of fan, will be trying someone said 50% works, so I'll start with 35% and see. Thanks for all the help again!

just have the fan off for the first 3 or 4 layers then 100% for the rest.

But printing at a lower temp will give you stronger prints.

yeah that was part of the problem, i had fan back on at layer 3, which is too little. RIght now trying a 9 hours print (crosses my fingers and knock on wood again) at 240 C nozzle, Bed at 80 C all the way, and fan at 0% until layer 5, which then it starts at 50%. The one before I tested with no fan worked almost perfectly, other than the usual stringing, which was very thing, here's hoping 50% is enough to eliminate that but not cause cooling down too fast on my Cr-10. Little nervous right now too because a part of the brim on the left side I didn't get the magigoo there, so right now it's straight on glass. Good thing it's the brim and not the part, but we'll see xD

Best,do you have to use any glue on the Ultrabase?

surprisingly no, just at least 80 C bed, I suggest 82 C though to be safe, because i had a case where the front side started warping just a tiny bit towards the end of a 12 hour print, which I'm guessing is due to the back usually hotter than the front. This is on the Anycubic i3 Mega

Is that for PLA?

no PETG. For PLA, 60 C for the bed and 196 C for the nozzle and fan depends on your printer but usually 70-100% is good for most (as long it's not cause nozzle temperature to run wild) is good enough. nozzle temps for PLA Really depends on the company though, I'm using Zyltech PLA and it's usually between 196 and 207 C for me for the nozzle.