A few times now on larger prints, those that consume most of the print area, I have had the corners lift, even with glued smooth plates. Is it bed heat? Reason I ask is I just started doing a print job with Anycubic white PLA and found it doing the same thing, previous job on a similar print, same job just revised for less supports, that I used Bambu filament on did. I looked at the bed temp and it was 70C, then looked at the specs on the Anycubic which calls for 55-65C, so adjusted the bed to 60C.
A brim with 0 object-brim gap can help. Personally I’m in the no glue camp on the smooth PEI plate. A really good wash always give me the best results.
It’s the PLA shrinking as it cools down pealing the corners. Lowering the nozzle temp may help. I found that slowing down the inner and outer wall print speed helped.
Well I know its not lack of stick to the plate. Went to pull the part and the plate came with it of the magnets. I think its the cooling too quick causing it. Reducing bed temp from what it was helped a tiny bit, but there is still corner curl, and only where its a square corner. Will try a brim too and turn AC down to 20%, looks like default is 30%. I printed similar parts using PETG without any issues such as this, so might just switch back to PETG for this project. There are two parts for this, and each one uses just under 700 grams, so its getting wasteful at this point. Had a support get knocked over during the night, looks like the third or fourth to last run of PETG to the support did it, and the following layer would have been the underside of the part, its all spaghetti now. Also causes a Z band shift where the two halves will come together leaving a gap. Going through different settings to get it to make a trunk instead of a wall. One part is using trunks, and it doing fine, this one used a wall instead and was unbalanced at the very top.
Then why is the rest of it so difficult to remove? Plate is clean, 100% glued. Rounded corners stay put, only the square corners lift. Why does it only happen on PLA and not PETG, and why does it also do it on the textured plate? Plates are clean, washed in hot water with Dawn.
There is some other force involved here to pop it off the glue, it’s not the plate. I am tryin a couple of the above suggestions to see if it helps, Cooling too quick seems the logical issue, so looking to see how to raise the chamber temps, its showing 27C at the moment.
PLA contracts when it cools, that is pulling the pla off the bed, so yes, it’s a bed adhesion issue as it’s not adhering to the bed, not sure how else to explain it
Your bed can be perfect and the PLA will still lift on larger prints because it has contracted at the edges, the rest of the print is hard to remove because it adhered to the plate properly and the bit that didn’t curled up when it contracted
Not many other ways to explain this, it’s an adhesion issue
If your plate is definitely clean and on smooth PEI, I’d avoid the glue and just 0 distance brim that entire thing, no need for rafts
Not every print can be solved by lashing glue onto the build area and some things require after-print clean up
I just realized something. I’m not printing with BL PLA but with another brand, but using BL settings. I wonder if thats the problem since I normally have zero issues with BL Filament, plug in and play. I’m using AnyCubic for this.
The first time I printed the parts, I used BL on one printer and I think Elegoo PLA on the other. I got lift on one corner of the BL stuff because I didn’t coat the entire plate, so the corner that did have glue did not lift, and the corner that did lift, only lifted a fraction, the other brand had complete and utter distortion.
Not all Filament uses the same settings, so on my next attempt going to try setting up the filament in Studio with the settings per the manufacturer and see if that makes a difference.
I have some adjustments to make on the platform where I somehow failed to merge a side rail with a wall, which left a gap, and forgot to round the back corners, so will require a third print. I can still use what I printed, just make a top for it and drawers, duct tape the mistakes and have storage for things, can never have enough storage. Hoping this third attempt produces a finished product. I have a few items I want to add to make it complete, but just getting the basic part down has been a PITA due to it’s size.
Bet its the Filament settings after what I just discovered. BL WIKI to the rescue once again, thats how I discovered what I did.
That could be bed adhesion, try raising the bed temp or cleaning the bed. Grease from your hands can really mess bed adhesion up. I washed my print bed and it really helped with that kind of stuff
Trust me, the plates are CLEAN. Washed with Dawn, a scrub brush, rinsed very well with hot water and dried with a new Microfiber towel and only touched at the edges. After pulling the last one off, I found the wall lifted, but the floor did not. It only where the 3 wall lines met at the corner, the rest of the material stayed stuck. I ran 3 wall loops instead of 2 because I changed infill to 10% and used Adaptive Cubic instead of default to use less filament in the rather large area that I don’t really need anything, but still need support for the top layer. It only lifted at the loop. I also used .24 Standard settings, so it has heavier lines. I am leaning more towards a settings issue than anything else from what I am finding. I have a job currently running thats using 3/4 of the plate with NO lifting and I have not touched the plate since the last job that lifted. This job is running on the .16 Standard setting with 4 wall loops, and added Outer Brim to it, and skirt height of 2 layers. It is also using the Elegoo filament that failed on my first attempt. In fact the corner of this one is exactly in the same spot that the last job lifted from. It is now 4MM tall and solidly planted.
I found a few more errors and adjustments to make before I run it again, hopefully for the last time, but I got all the dimensions down exactly how I want it, just some minor changes where I missed something internal. Hopefully I solved the support issues where it gets knocked over after reaching a certain height, looks like Z lift is disabled by default so the Z doesn’t drop when moving between infills, which appears to be what happens when I watch it work, it moves from support part to support part without the bed dropping so the nozzle touches the support before it applies filament causing the entire tree to move. Once the tree get above 120mm or so that when it gets knocked around. In this last job it was laying the PETG layer down on top when it got knocked over at 131.9mm in height. Looking close at it the PLA layer that acts as the bridge is where it failed, it clumped on a few of the tiny branches that left holes so the PETG fell through and clumped so the fourth to last pass knocked it over. I also notice bulging on the wall facing in to the middle which is opposite the side that failed, so that had to contribute to it as well. This was a block support, not a tree, which is weird as the other part for the same opening used a tree that worked perfect. I had to fiddle with the settings to create a tree support instead of a wall. I’m thinking the bulge pulled the outer side up just enough to cause a clearance issue on the support branches which led to the pla to PETG layer to fail. I believe that to be a cooling issue as well, so looks like this all leads to the settings for the Filament more than anything else. The current one running is the Elegoo that I adjusted the settings for to match what they recommend. So far, So good.
Looks like it was purely settings causing the issue. Ran some calibrations on the filament, created a profile for it and was able to print without lifting corners. Increasing the layers before cooling seemed to make the biggest difference, started out at too before cooling, and increased it to 5 and now can fill the entire bed and not have a corner lift.
Ran across this video from 2 months ago. He does a good job in explaining why I was having the problems I have. It not the plate, its the print. Basically in the long walls the cooling of the long strands it actually pulling inward, lifting the corners. With each subsequent layer, more stress it added, and no amount of glue will stick it to the bed. Going to give some of his tricks a try and see if it helps.
Not always applicable, but a cool plate also can help. If the bottom isn’t glassed from temperature, it puts up much more resistance to things trying to contract above it.
& 
