I am suddenly getting a lip on the top and bottom layers of my print on my A1 printer that has to be manually sanded off post-print. I can’t figure out what the problem is. If anyone can help me troubleshoot it, I would much appreciated it.
Here is more detail about the problem:
The lip extends around the entire perimeter of the print on the top and bottom layers. The lip is about 0.2mm thick. It’s hard to get photos of it, but it’s very noticeable when holding the print.
This has only recently started happening on my A1 printer; it has not happened before in hundreds of prints.
It does not happen using the same filament on the same model in my P1S printer, so it’s clearly a problem with the A1 printer.
Calibration of the printer did not help.
Using a new filament fresh out of the bag did not help (so it’s not a moisture issue; I also have about 36% humidity in this room, anyway)
There is no warping of the print, so it’s not an adhesion issue.
I’m using Bambu Lab basic PLA filaments.
Changing colors did not help.
The slicer settings are standard 0.20mm Standard settings in Bambu Studio.
I’ve done some searching for similar and found someone else that has had the same problem, but there was no good solution for it:
Huge elephant foot is lots of “first layer” type problems - could be too much heat, could be a bad z alignment placing the nozzle too close/squished to the plate, could be an actual 0 in your elephant foot compensation when it needs to be nonzero, etc. Maybe other users who use matte could chime in. Try sending a small 50x50x0.2mm square to your printer and see what the first layer looks like.
It may be a trick of the camera, but it sure looks like it is warped/curled up on that bottom corner. If it warps later on in printing, the model moves in real space upwards, and the nozzle now is trying to squirt plastic into a space it thinks is unoccupied, but is now occupied, and it gets smushed out the edges or can crash into the model. Lifting/adhesion problems can have novels written about them, but in general I would recommend cleaning your plate well (hot water, unfragranced dish soap, dedicated clean sponge/scrubber) as first line of defense
2a) “fresh out of the bag” != dry. I know it feels like it should mean that, but it doesn’t. Especially with clear plastic packaging. PLA is pretty forgiving though, doesn’t need to be 0% bone dry.
I’m sure it’s not an adhesion issue because it happens all the way around the print. Yes, the corners are pulled up a tiny bit, but it’s not pulled up anywhere else and the problem is the same around the entire perimeter.
It’s so consistent that it’s almost like the top and bottom layers have a different width assigned to them in the gcode than for the rest of the print.
Some more photos of the problem. It’s very hard to get a good picture of what’s happening, but essentially the sides are straight except for the top and bottom layers which stick out about 0.2mm.
After a great deal of experimentation and troubleshooting, I managed to fix it by:
Lowering the bed temperature from 65C (default) to 55C. This fixed about half of the problem but didn’t make it go away.
Quadrupling elephant foot compensation from 0.075mm to 0.30. This fixed the remainder of the problem.
I still don’t know why it suddenly started doing this or whether it will continue to be a problem. I don’t want to have to remember to increase the elephant foot compensation every time I use my A1 printer. (Note that this only affects my A1 printer, not my P1S. The problem does not occur if I print the same 3D model with the exact same roll of filament on my P1S.)
Here are all of the things I tried that didn’t help:
Changing filaments did not help.
Calibration did not help.
Changing hot ends did not help.
Tightening screws in the print head and on the back of the hot end did not help.
Tramming the bed. This was way off despite the fact that I trammed the bed about 3 months ago, but this wasn’t the problem.
Yeah, so changing the elephant foot setting only fixes the problem if I change the elephant foot setting for every single project. It’s only a temporary fix, not a solution.
I still don’t know why my A1 is doing this. It only started recently. It otherwise prints just perfectly. But, on every print it leaves a lip sticking out on the first layer, almost like it’s printing an extra outer wall on the first layer.
