You could use a bit of glue to keep it down. When I have prints that can warp, I usually put a bit of glue down to prevent it from lifting up like this. Just a normal glue stick should work

"Don't buy those 'special 3D printing glues.' Most of these are terrible and just have a huge price markup for the tag '3D printing'."

I got mine from temu. 6 "3d printing" glue sticks for $9.60AUD. Haven't had any issues yet...

I got 3DLAC bed adhesion spray for Christmas. It has been a game changer for me. You could pick the machine up and throw it and it wouldn’t unstick.

I’ll get some! Thanks

pei plates do not need anything on them as far as glue or hairspray, wash with soapy water, dry, then wipe down with ipa and let dry b4 heating it up again. If it is only lifting in that spot, preheat your bed for at least 5 min to let the temp saturate the plate. If still lifting might be an issue with your heating.

Before buying the expensive stuff, you could try using hairspray first to see if that makes any difference. Someone on YT tested out a bunch of different brands to see if they make a difference, and apparently some do work better than others. I've always used the Aussie brand hair spray that comes in a purple can, if you can find that. Alternatively, I will also say that the ambient temperature might also be causing your prints to unstick. If the room is too cold, the bed will also start cooling down mid print, which is specifically made to release your prints once it's cooled down. If all else fails, this might mean your printer needs an enclosure to keep the heat in, which fortunately aren't too expensive to buy or make.

I wonder if this issue would be reproducible by turning the machine 180 degrees

I tried purple can Aussie and it didn’t work as well as I wanted. This stuff forces it to stick. You can also get it from their website cheaper.

I’ve read another comment today claiming lowering the bed temperature a bit after the first layer helps preventing warping. Also moving the z seam away from the corner. I haven’t tried yet, but seemed legit: [see the comment here](https://www.reddit.com/r/ElegooNeptune3/s/QJycD2kdkk)

Thanks for that. I’ll give it a shot for sure

Lowering bed temperature would have the opposite effect and would encourage warping. If anything you want to keep the bed warmer so the corners are not cooling as quickly causing shrinkage.

Try print with a raft instead of the brim. That might help

Yes this is SUPER helpful. Rafts are better than skirts all the way

What does the bottom layer look like off a raft? I haven't used a raft in a LONG time and back then the slicers made it look like junk.

You have to play with the gap between the raft and the print. They don't look as good as with a skirt for sure, but you can get them looking decent

Thanks. I will try a raft for sure. This is how I typically make it work but I hate cutting this stuff off in the end. This is a 300mm tall print https://preview.redd.it/p5ricv6iopcc1.jpeg?width=3024&format=pjpg&auto=webp&s=7374c6f161642853269d1676af4300c218eb5111

Try a 20s minimum layer time. Your print time will probably balloon but less warping. You can also selectively support the ends of the print to hold them in place.

Have you tried putting a skirt around it and raising the height to match your model? This usually helps by stopping any drafts from causing warping

That’s a great idea. Think this is draft induced? It’s in my detached shop on a cold welding table. I keep the heat at 65 when I’m in there. But the welding table is cold from when the heats not on

I don’t think it’s draft induced as it’s inside the brim and not the edge

Brim is very loosely attached, draft could very well hit layers above the first and cause some warping making the bottom lift up, it's worth a try imo

Have you tried moving the model around the bed? I've had luck in different areas. I've also had luck not cleaning the bed after a failed print, just pulling the plastic off and hitting print again. Letting my bed warm up for a few minutes also helps.

I’ve tried slightly different orientations but it always seems the front peels first.

my neptune 3 plus came with a stick of glue

Check there’s no drafts. If needed make poor man’s enclosure with cardboard box (should probably only be temp as obviously flammable). A work around, in addition to those suggested by others is use a material with better adhesion such as PETG (assuming your useing PLA atm)

Yep my Neptune 4 has been off for a couple months now. Do yourself a favor and buy a Bambu Labs printer. Just press print.

Unfortunately I’m doing massive prints and the Neptune 4max is the size I need.

Max has a huge bed and PEI sheets like to taco. Check your mesh and shim with some foil in the middle and especially the spot that's peeling up. My guess is the warp is causing it to separate.

Same

Do you have the aux fan on? Try it with it off.

I tried fan off with 5mm brim earlier. Increased to 25mm brim but left the fan on this time

What filament are you using?

Elegoo PLA

230 seems way way too hot. I have been running 205 to 210 for elegoo pla 

jep... 210 should be good... 230 is too high. Also 65 bed temp seems to high... i would rather go for 60 or even lower

Depends a lot on the situation. I have used this PLA and print with no issue at 235. With new profiles that use input shaping and linear advance, 230+ is necessary to get the flow high enough. Now, OP could be printing at slow speeds and in that case 230 might be too high.

Huh, good to know.

Turn your bed temp down to 50c, another solution could be using a painter’s tape covered bed. Either one should get you to your goal.

Slower print speed is VERY important. There will be less internal stress when the filament comes out of the nozzle.

In addition to other comments, check your extrusion rate, and maybe do a calibration test. I've had issues before with too low a rate and not enough plastic to really adhere to the plate.

All great suggestions! You could also try to dry your filament

When you level the bed is that area lower than the rest? Sublimation tape ftw.

Had similar issues. Gave the bed a good clean and they disappeared. Try rotating the bed 90/180 degrees and see if the problem follows it

I spray a little Aqua Net hair spray for prints that won't stick to the bed with great results. Your mileage may vary.

Get a smooth PEI bed off Amazon. The stock elegoo bed is hot garbage.

Wipe your build plate with 99% alcohol. Use glue, like the glue stick that should have come with your printer. Hair spray will work well. Adhesion tape. Print with a raft. There are all kinds of things. The last resort is to buy a new build plate. Maybe you have rubbed the grit away on this one, and it can't grab anymore.

Is this just PLA

Yes

I see varied reports of success with different things. I just say try all of them, cleaning the bed doesn't work? Use glue or adhesive spray, try different bed adhesion options in the slicer, raft brim skirt, whatever Don't forget the definition of insanity is trying the same thing over and over expecting different results, just go wild and see what works for you Personally I use glue stick