Corners Releasing, Upsetting Higher Layers?  

RE: Corners Releasing, Upsetting Higher Layers?

Bed adhesion is down to two or three factors: layer 1 extrusion, heat, and cleanliness.

Corners lifting due to part warp can be reduced by printing inside an enclosure; using a higher bed temp (70c); and ensuring the bed is contaminant free.  

Alcohol isn't as effective at cleaning as soap and hot water: at the base level it's a simple matter of rinse volume. A ten liters of water will rinse more than a few ml of alcohol; and alcohol does not remove some residues of printing.  Water is just better.

RE: Corners Releasing, Upsetting Higher Layers?

And that great bugaboo - use a brim. On big structures like this they really help hold down the corners

A useful article to explain why your corners lift is:

https://eleccelerator.com/prevent-corner-lifting-3d-printing-overkill-method/

RE: Corners Releasing, Upsetting Higher Layers?

A brim might help by increasing the radius of the corners ... but per the article the author even admits a standard 1 layer 20 mm brim didn't do much to save his part: so he resorted to a full redesign to redistribute the thermal stresses.   

I've found that reducing the print fan speed is almost as helpful as increase bed temp ... but I use a smooth PEI sheet.  The PC has known issues with PLA adhesion until properly cleaned - and that's probably what is exacerbating Eric's prints.

One other option I've seen recommended - I haven't tried it - is to print a full height skirt to help keep temps in.  It's effectively what the author said he finally did with his part changes. 

RE: Corners Releasing, Upsetting Higher Layers?

I don't view the brim as helping by increasing the radius of the corners as much as "gluing" down that section.

The brim is firmly attached to the plate, and the part will actually have to rip it to lift.

Wish I had an easy way to do "mouse ears". Maybe that and having a 3 layer brim there.

RE: Corners Releasing, Upsetting Higher Layers?

I was going to ask about this exact thing but is it all your corners or just one? On mine I used the bed visualisation plugin for octoprint and can tell one of my corners is higher than the others (the one where it is lifting). I was going to ask if anyone knew how to 'level' the bed as something to help the mesh levelling.

RE: Corners Releasing, Upsetting Higher Layers?

In Prusa Slicer, right click on your part and add modifier.  Make it a cylinder and then adjust to the size you want, make z however many layers you want the mouse ear to be and place where you want them.  Once you have 1 you can copy and paste them to other spots.  Quick and easy mouse ears.

RE: Corners Releasing, Upsetting Higher Layers?

Posted by: @neophyl

In Prusa Slicer, right click on your part and add modifier.  Make it a cylinder and then adjust to the size you want, make z however many layers you want the mouse ear to be and place where you want them.  Once you have 1 you can copy and paste them to other spots.  Quick and easy mouse ears.

I like this! Gotta try it...

RE: Corners Releasing, Upsetting Higher Layers?

Very helpful posts, thank you. It appears I can resolve my lifting corners, but not the external line midway up the print.

It seems to coincide with a transition from layers of mostly infill to mostly solid top layers. Does this mean overextrusion?

RE: Corners Releasing, Upsetting Higher Layers?

Print speed is generally the culprit for those fat perimeters.  Check the Filament Cooling value: and preview the print speeds in slicer.  The default 20 seconds and 15 mm/s can be changed to get a more consistent print speed.

RE: Corners Releasing, Upsetting Higher Layers?

@eric-s-falk

I don't know that you've solved the lifting corners quite yet. In your photo that bright brim color nearest to the model suggests it's still indeed trying it's hardest to pull up and away despite the brim.

When you pulled it off the bed, did you notice  any puckering around the edges there?