Can't figure out this error - corners lifting during print  

RE: Can't figure out this error - corners lifting during print

Most likely bed isn't level unless you got a raspberry pi I'd suggest you contact prusa support though live chat 

RE: Can't figure out this error - corners lifting during print

Are you cure your z offset is perfect.  Print a single layer print right where that is and see if the lines of filament fully fuse.  

RE: Can't figure out this error - corners lifting during print

I've had that happen with some of my PLA models that are large.. a few things you can do to help..  This assumes your bed is level.. If you have octoprint, you can add a plugin that does bed visualization and it will tell you how flat your bed is..  The following also assumes your Z is good ... but I suspect it might be something else

1. Get an infrared thermometer to ensure your bed is getting close to 60.. But for those large prints.. increase the bed temp to 65 .. 

2. Add glue stick.. I know, people will say not necessary for PLA on the smooth sheet.. but that will give you some 'extra' stickum .. 

3. Check to see if you are getting any drafts where you are printing.. do you have a fan on.. air currents can sometimes cool the outer edges of the print and they might warp. You can maybe ensure your printer is in an area where it stays nice and hot.. 

4. Add a brim .. might help stick down the edges.. 

Just a few things you can try.. 

RE: Can't figure out this error - corners lifting during print

This is pretty common. The higher layers will shrink slightly when cooling down and peel away the bottom layer from the print bed. As crab said: use a glue stick or magigoo or any other stuff to improve bed adhesion and/or add a brim.

RE:

I'd start with a thorough cleaning of the bed surface (hot water and dish washing agent or lots of IPA and paper towels).

Next up (as Chuck said) first layer calibration - redo it and post a picture of the square.

Things to also consider: drafts (as crab said), temperature (hot end and bed), quality PLA, infill and bottom thickness (to many solid layers on to of each other increase the bending up effect), brim (to increase adhesion where it's needed)

Things I'd stay away from: Glue-stick, because PLA sticks on the smooth PEI very nicely if it's clean and at the right temperature. Any "leveling"-mods, because nothing needs to be level, axis need to have 90 degree angle to each other and the bed surface should be reasonably flat (minor deviations are compensated by mesh bed leveling (yes, stupid name, it does not level anything) consider 7x7 grid, make sure magnet compensation stays switched on). And (initially) the "bed level correction" because you will most likely make things worse by using this if it's not the root problem, use this only as last resort.

RE: Can't figure out this error - corners lifting during print

Glue stick works really well in some situations.. It is not something you want to stay away from, but you should not need it for most prints. It gives a better 'grip' than the flat surface and has many, many uses. Small surface area parts can have a hard time sticking.. and especially if they are things like gears, you don't want a brim. So for those. glue stick is really a nice option. If I'm printing a lot of PLA on the smooth PEI and maybe one PETG part, I'll leave the smooth PEI on and just add some glue stick in one area and print the PETG part (glue so it will release without damage of the smooth PEI). Glue stick and other products are a part of your "toolkit" that can be very useful in certain situations..

 

Things I'd stay away from: Glue-stick, because PLA sticks on the smooth PEI very nicely if it's clean and at the right temperature. Any "leveling"-mods, because nothing needs to be level, axis need to have 90 degree angle to each other and the bed surface should be reasonably flat (minor deviations are compensated by mesh bed leveling (yes, stupid name, it does not level anything) consider 7x7 grid, make sure magnet compensation stays switched on). And (initially) the "bed level correction" because you will most likely make things worse by using this if it's not the root problem, use this only as last resort.

RE: Can't figure out this error - corners lifting during print

Posted by: @crab

Glue stick works really well in some situations..

it does in deed. But the OP asked about PLA on the smooth PEI. Which is not one of those situations in my experience. I use glue stick a lot when printing PETG on a glass bed and to glue paper together. So: thumbs up for glue stick in  some situations. I did not mean to stay away from it at all times. Sorry if I did not make that clear - my bad. 

RE: Can't figure out this error - corners lifting during print

Hairspray works wonders for things like this. Seriously. 

Just spritz a little on the sheet before you start the print. 

RE: Can't figure out this error - corners lifting during print

I use a glue stick for all my prints. Also PLA on smooth PEI. Better safe than sorry. It is cheap, easy to apply, environmentally benign and easily washes off with water.

RE: Can't figure out this error - corners lifting during print

Posted by: @annevanleyden

I use a glue stick for all my prints. Also PLA on smooth PEI. Better safe than sorry.

Sure Anne, nothing wrong with that. But I do not and I dare to say most people do not. Which suggests, that it does not hurt (your experience clearly shows that) but also that it is not necessary (my experience and prusa‘s for that matter https://help.prusa3d.com/materials  ). You can also jump three times and knock on wood everytime you start a print and produce perfect results every single time - recommending this procedure to somebody with bed adhesion problems on the other hand will probably not work as intended…

As for the OP’s problem, glue stick will probably not be the solution, the problem is something else. 

RE:

All, thank you for your input. I haven't been responding much but I've read all of the comments I've received. I checked the consistency of the temp across the bed, checked the bed level, and ended up running a bunch more test prints. I also ran test prints at different bed temps because the bed temp wasn't as warm as the display indicated. I upped the bed temp a couple degrees, lowered the z-a bit more to increase adhesion between the lines on the same layer, and I think the other issue is there is the room the printer is in tends to get a lot of sunlight but is also a bit drafty. I'm trying the original print I posted about again now with a 10mm brim and the bed set to 62 degrees. We'll see how it turns out this time!

RE: Can't figure out this error - corners lifting during print

Corners lifting, particularly with PLA, would indicate to me that it's most likely an adhesion issue as opposed to a cooling/warping issue.

I suggest trying an adhesion booster, either something as simple as glue stick, or a product sold for the purpose such as Layerneer or Magigoo.

For large rectangular items, I will often times dab a bit of Layerneer right where the corners will hit to minimize the tendency to pull up.

Glue stick can be messy and thick, and it can indeed leave an impression on the underside of the print.  Commercial adhesion boosters (or even hair spray) go on much thinner and usually leave no marks.

Speaking of hair spray, a while back I posted an item reflecting on the speculation that Layerneer was actually re-packaged hair spray.  I took a bottle of Layerneer to the stylist that both I and my wife use and she said that it feels very much like a so-called unscented non-aerosol hair spray and mentioned a brand (forget what) that it  could be.  I'm not going to cheap-out and try using a hair spray, since I like the applicator bottle of Layerneer and one bottle lasts a very long time.