Hello everyone, I’ve had my printer now for a month and am looking for some advice on how to improve the quality of this printed arc shape that I’m attempting to get right
Below I have attached an image and the 3MF file of the part in question. At the bottom of the part there is a 14x14x14mm hollow for attaching it to other components, and in the area where this hollow exists, the outer shape is printed in a different arc than in the area where there is no internal hollow. The hollow should be 1,6 mm from the surface so the walls should have sufficient space, and in the slicer there is no visible indication that the print is going to go any differently. Similar artifacts exist on the opposite side where the margin between the hollow and outer wall is about 2,6 mm
I’m printing this on an A1 Mini out of Bambu Green PLA, default settings other than the gyroid infill that I’m trying out. I have drawn the model in Fusion 360 and exported it to Bambu Studio as 3MF. The artifacts are present with both the classic and arachne wall generators, with arachne the artifact is less pronounced but the division line between the layer with the hollow and the next layer is very similar to that of the classic generator
Is there some Wall generator magic I should change to get a uniform surface or what could be causing this?
Front right column bottom.3mf (5.7 KB)
Looks like it’s a speed question, the section with the hollow in it gets more support from its structure and can be printed faster, which then makes the arc appear different than higher up where there’s less support and thus slower speed. It seems like slowing down printing speed of the outside wall to the lowest common denominator is the only way to get consistent results
I’m not really sure what the “defect” is. That print looks pretty good to me. If your expectation is that the print will look like it came from an injection mold, your expectations may be too high.
If I look really carefully, I think I see a little bump on the outer wall that I am guessing aligns with to the inner “top” of that hole. If so, this is the “Water Line” Benchy problem. Changing the wall print order to outer/inner/infill might help minimize it further. But the defect is visible because of a limitation of the FDM printing process and there is no way (that I know of or have seen someone suggest) to get rid of it entirely.
If you’re printing the part standing vertically on the plate, you might try printing it with one of the long flat edges down. You’d need supports so the underside won’t look as pretty, but if the underside in your picture is “inside” the final assembly it won’t matter.
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Yes I may be being too meticulous, I do expect some angles to show along the vertical edge of the object but those angles get printed differently in the layers where the internal hollow exists. Most likely the same instructions get sent to the printer but the speed at which the printer performs the instructions makes the resulting shape look different
But I’ll tune a compromise with the outer wall speed to make the difference less visible
