1w ago

Print refusing to stay flat in corners

I’m hoping you guys can help me figure this out. I have an ender 3 pro, running on marlin firmware. Every time I try to print something one of the corners will lift up like that and ruin the entire print. I installed a crtouch to help with leveling, installed upgraded metal bed wheels to help it not fall out of level. Even tried a glass bed with glue and it still does the same thing. I used a filament dryer and have a heat enclosure. I’m starting to run out of ideas on how to fix this. Any suggestions? The pic is how it starts and that was just a brim since I used to always use a raft and thought I should try that instead.

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You can try turning up the bed temp, lowering the z-offset to get the nozzle closer on the first layer, or increasing the first layer flow in your slicer. For me the purple glue sticks on a glass bed worked, but sounds like that’s not working for you for whatever reason.
Another trick I’ve seen people use is adding some circles to hard corners like that in the model that you can cut off later.
- I’ll need to figure out how to make the mouse ears that everyone suggests. I haven’t actually made my own models before and the brim is automatically made with the creality slicer. I tried cura as well but that was doing weird things with the print if I recall so I went back to the creality one. If I can’t figure it out on there, I’ll see if cura gives me more options for that. Thanks for the info
  
  Find an stl of a disk and then overlap it with your part
  
  There's also a few plugins for Cura with variations on the name TabAntiWarping. I've had https://github.com/5axes/TabAntiWarping installed forever but I'm not sure if I've ever actually used it in a print. I just took a quick look and there's a couple others listed in the marketplace now too.
  
  You can do the mouse ears in the slicer too.
- I had a similar problem on my Neptune 4 Max, and the solution was actually to lower the bed temperature by about 5 degrees C.

Because nobody said it yet: wash your bed with warm water and soap to remove any residue (especially oily fingerprints)
- I have washed it a couple times and was getting the same results. I’ll try again just in case.
  
  Better solution than water and soap: Clean it using isopropyl alcohol on a clean rag (no paper tissues). Works much, much better.

If PETg (which is where I've most commonly had warping), make sure Filament is very well dried. Try both raising or lowering bed temps and bigger brim.
Also, for funsies, try rotating print orientation 45 degrees if you can. Might shift stress away from corners to sides.
- I might also try changing how the print sits on the bed to make it print more like a diamond instead of a square shape, since it’s always one of the back corners that start the lifting. Not actually sure it that would help but who knows
  
  it’s always one of the back corners
  If it's always in the same orientation, it also can be caused by cold wind. Look at your enclosure ventilation, or try putting an obstacle there if there isn't an enclosure.
  
  Exactly, that's what I meant

Have you tried adding a brim or mouse ears to remove later?
- The picture is actually the brim of the print. It hadn’t actually gotten to the first layer yet. I’ll have to figure out how to do the mouse ears since that seems to be a common suggestion.
  
  Some slicers can add mouse ears automatically along edges where it'd be likely to lift up. I believe it's been a feature in orca and its derivatives for some time. Otherwise you can add very thin, single layer cylinders to the corners. Most slicers out there have features to let you add common primitives like that.

What kind of filament are you using? I’ve had that trouble with ABS before and what worked for me was making a slurry of acetone and some scrap filament and painting it on the glass then adding a brim to the model in the slicer. With other filaments, it’s always been playing with the temps and using a brim in my experience.
- I use pla or pla+. I’ve played around with the temps but usually to a higher temp. I’ve seen some suggest a lower temp so I’ll give that a try and see if it helps

Cleaning is a good suggestion. I'd start there.
Also, that kind of looks like the cheap black textured plates that come with some printers. I thought the people talking about pei sheets were over-hyping but honestly they are really much better. It's not a silver bullet but pla sticks soooo much better to them.
For pla it's overkill, but for tricky stuff build adhesive can help. I had good luck with vision miner. It's expensive but it's been buy once, cry once because it has lasted a really long time.
- I’ll definitely take a look at the pei sheets, that’s the first I’ve heard of it. Thanks for the suggestion!

From my relatively lesser experience I can suggest a couple of easy things to cross off your list.
look at first layer thickness, not sure how thick you’re going but thicker material is more likely to stick and stay put.
reduce cooling (eg fan speed) in the first couple layers to promote adhesion
as others have said, clean your print bed, I’m a fan of isopropyl.
increase bed temp by 5°C
slow your first layer(s) further.
I am certainly no expert- these would be my first ports of call before I start praying to the google-fu gods.

Given all you've tried I can only conjecture that this may be a print temperature issue, especially since you already tried adhesive. What material are you printing, and at what temperatures for nozzle and bed?
You may also find that your printer's sensors are not reporting temperature accurately. Mine sure isn't and never has, at least on the bed, and it consistently reads about 5 degrees high versus reality if you poke the surface with an external temperature probe. This isn't a big deal only so long as you know to compensate for it. The thermal conductivity of whatever your print bed material is may also force you to compensate, i.e. a glass plate will not perform the same as a steel one and may require a boost of a few degrees and/or allowing it to cook longer during the preheating phase before you start your print.
I print on a sheet of cheap Kapton tape with a later of even cheaper hairspray on it (Aqua Net, if you must know), "65" °C bed temp for PLA (60 in reality) with a first layer temp of 215 for regular PLA, and 210 for "rapid" PLA blends. My sharp corners stay put.
- I’m using pla, I didn’t think about the temps being wrong though. I usually heat it to 200C and 65C respectively. I’ll have to get an external thermometer to check that out

- This really doesn't look flat enough for a brim. Is your nozzle close enough to the bed?
  
  I did level it using paper and using the crtouch. I’m not sure how I could get it any closer
- use a few mm of brim
  
  That is the brim, according to OP.

So I gave it another try with the black filament after doing some additional adjustments and was still getting the same issues. I then swapped to a brighter filament so that I could get a better picture and now it’s laying perfectly flat. I’ll let it continue printing to see if any other issues pop up, but it’s weird that one filament was lifting but an older spool works fine.
- Gave it some time to print and unfortunately it lifted up again. Going to wait for the thermometer to come in and see if that corner is heating properly
- Different brands/colors can have totally different additives that affect bed adhesion - might be worth checking if that black filament needs more thorough drying (even if you used a dryer, some PLA needs 6+ hours at proper temp).

~~ haven’t seen anyone mention this somehow, but this is most likely caused by a draft hitting that part of the print and causing it to cool at a different speed than the rest. Easy test, get a big cardboard box and put it over the printer and redo the print. You might need to invest in a cheap printer enclosure ~~
Edit: never mind I totally missed the part where you mentioned you had a heat enclosure

So I gave it another try with the black filament after doing some additional adjustments and was still getting the same issues. I then swapped to a brighter filament so that I could get a better picture and now it’s laying perfectly flat. I’ll let it continue printing to see if any other issues pop up, but it’s weird that one filament was lifting but an older spool works fine.

- I’m using pla. I know my printer had something about a mesh in the settings but I don’t think I’ve used it, I should read up on it to see if it actually is set up to do that. The brim is what’s actually lifting off.

What is the (approximate) ambient temperature of the room it's being printed in? Are there drafts (wind)? Have you tried cleaning the plate and then using glue (which shouldn't even be needed for PLA)?

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