1st layer warping issues with PLA
Hello,
I've some issues printing the first layer of a relatively straightforward model - it's basically an oval-shaped wall, imagine a can without a top or a bottom. When printing the first layer the material doesn't seem to stick to the bed properly - it warps away in places, or becomes detached completely in others; and since it then essentially raises a little higher the printer would soon catch on it and damage the print further. Sometimes the exact same printing error happens at the exact same place even though some settings have changed and the area in question is perfectly smooth on the bed.. I'm using Slic3r 1.35.5.21-prusa3d with the latest 3.0.9 firmware on an i3 mk2; the material is a white PLA of unknown origin, but exactly the same issues were observed with the stock black PLA I got with my printer.
In the attached picture you can see one of the issues that I believe to be representative of the whole bunch. The part that is being printed is actually the brim: you can see one loop of skirt and then a number of loops that are all part of the brim (the wall itself is only 1.6mm thick, so I added 6mm of brim to improve adhesion to prevent it from warping higher up). The innermost loop of the brim has sort of a warped edge, which only gets worse in the next loop and so on.
I always clean the bed quite thoroughly. I've tried adjusting the live Z offset. I've gone through the whole XYZ calibration twice, then V2Calibration maybe 10 times again, I've even looked into bed correction and applied some. I've cleaned up the nozzle, both from the outside using the supplied needle and from the inside using the Atomic method. I've experimented with different temperatures for the first layer. I've slowed the first layer down to 40% (the default settings say 70 is okay).
I got to a point where I can maybe get the thing to print one time out of 3, and the first layer still sucks and I have to worry all the time that at some point the thing will just unstick from the bed on one end and destroy my P.I.N.D.A. while I'm not looking or something.
Please, please help me!
Re: 1st layer warping issues with PLA
This is no warping, this is overextrusion or you print too close to the bed. Check 1st layer calibration. Raise the nozzle about 20µm.
Thomas
Re: 1st layer warping issues with PLA
This is no warping, this is overextrusion or you print too close to the bed. Check 1st layer calibration. Raise the nozzle about 20µm.
Thomas
Thanks, Thomas, unfortunately I've already tried raising the nozzle quite a number of times and the result is still the same, up to a certain point where the nozzle is apparently too high and I lose adhesion altogether, resulting in deformed shapes because the nozzle drags them behind. But I'll definitely look into overextrusion to get further ideas.
Re: 1st layer warping issues with PLA
Further elaboration. Attached are two screenshots of a section of the first layer from Slic3r's preview. In the first one you can see the brim and the walls and in the middle there's the base of a support that the object needs higher up. The second one shows one of the ends of the object - the other end looks pretty much the same, except for some differences in sizes / placements due to the other end having a larger overall diameter.
This is what I observed over multiple attempts:
So the bottom line seems to be that I'm actually under-extruding or that the nozzle is too high for the support base and the object itself, but over-extruding or nozzle too low for the brim. Unless I'm missing something, that could only be caused by Slic3r, either because of a bug or because my settings are wrong.
I sliced the object using 0.25mm layer height (including the first layer), 100% concentric infill for both top & bottom layers as well as inside the walls, 5mm brim and supports using the default settings from the 0.20mm NORMAL preset except for XY separation, which I raised to 1mm due to previous issues with supports getting stuck to the sides of the object. I also reduced the first layer's speed from 70% to 45%. Otherwise the default settings for Prusa PLA 1.75mm and Original Prusa i3 MK2 were used.
If anyone has any insight on why this might be happening (overextrusion when printing brim, otherwise underextrusion), please do share 🙂
Re: 1st layer warping issues with PLA
Sometimes I have the same issue.
But this is an indicator for me to raise the nozze about 10 to 20µ and it prints fine. But it happens mostly at the center of the first layer print not at the outer rims.
Interesting is the brim, I didn't explore this until now, but maybe it can be the problem.
Never print with 0.25 layer height.
Thomas
Re: 1st layer warping issues with PLA
Downloading the latest version of Prusa Slic3r (1.36.2) should fix your problem, this is a known bug that was fixed in version 1.36.0.