Bubbling on top surface of print and corner lifting

We have been having an issue where sometimes the top surface of a flat print will bubble over the honeycomb pattern. Also having some issues with corner adhesion. I’ve looked up the various methods of solving the adhesion issues, but have not seem anything on the forums about the bubbling. Will try cleaning and sanding the bed, lowering the x stop, adding a brim, and releveling the bed. Any ideas about the bubbling? Printing with PLA with the default Cura settings.

Looks like the top layer is too thin. This could be a combination of the layer height and number of top / bottom layers. Cura looks to calculate this for you when specifying a shell thickness. Typically a 1.5mm shell is a good standard for the shell / skin of the print. This should provide for a fairly strong part.

As for the corner lifting, strange that its happening with PLA. Can you post a picture of the project bottom? Warping could indicate a un-level bed… one corner could be dipping. The best way I’ve found to level the bed is through the use of dial gauges to allow for a more quantitative calibration. My preference is to use two gauges on either side of the toolhead using these brackets. Here’s a pic:
If you’re pretty certain your bed is level, try anchors in addition to brim. Some folks call them “Mouse Ears”… In any case, its basically adding thin discs to problem areas (typically corners) for better adhesion to the bed. There are a few on Thingiverse, but they go by different names… I’ve attached a version. Scale the disc in the XY, try to keep Z constant… its .5mm thick which is still pretty easy to remove.

The other thing you could try is to add negative Z-offset (found in the Machine settings). which will move the nozzle closer to the bed. This should improve adhesion. Don’t use too much, try increments of -.1mm. Might need a good part removal tool also.

Hope some of those tips help!
Anchor - Square.stl (2.85 KB)
Anchor - Disc.stl (22.3 KB)

Did you forget the sample of the anchors?

Sorry. Adding them to the post.

Thanks for the advice. Will look into those dial gages. Seems way better that the other way. I’m never quite sure I’m measuring exactly the same points on all sides. Here is a picture of the bottom of that print. Both corners on the left side have pulled up. This is the worst print we’ve gotten as far as both issues. Will bump up the top she’ll as well. The default setting was 1mm, which is what this was printed at.

Judging from the print, your initial nozzle height looks good.

Does it consistently lift off the same side of the bed? May want to try sanding with a fine grit. I regularly use a Mr. Clean Eraser Sponge… just abrasive enough to get rid of any oils.

PLA likes to be cooled throughout the print, so make sure the fan is on from the first layer.