Yesterday I was printing the first part for the vision enclosure from humebeam (Printables). I was printing in Bambulab ABS with the Bambulab ABS profile. I did the following changes to the profile:
infill 25%
brim 10mm
wall loops 3
I used the printers shipping box as enclosure. Unfortunately the print has some defects:
Can someone tell me what went wrong and how I can fix it? The previous ABS prints with this method (aux fan stand, chamber fan duct) were pretty good.
I did some research by myself. Is it possible that this is caused by overheating? The part is only a few mm thick and the layers take only a few seconds.
I am new to 3D printing, so I hope for some help from the community. Thanks a lot.
You’ll want to print those with as many walls as needed to make it solid i.e. use an arbitrary figure like 10. And chose arachne over classic. You may still have to slow the print down to make those edges look nice.
I played around with classic and arachne wall generator in the slicer. While doing so i noticed that the print errors are exactly in the places where the seams are stacked:
If you chose random you may end up with noticeable dots all over the surface which will look worse IMO. You can also paint the seam so it will end up being at the back of the part so it’s not noticable. However, the issue with the corners looking ugly will likely still be present. I think you’re best bet would be to slow down the inner and outer wall speed to say 50mm/s. You can also try printing 2 of the pieces at once which will effectively increase the time each layer has to solidify.
Is your ABS filament inside a filament dryer or is it exposed to ambient conditions?
ABS is hygroscopic, it absorbs moisture from the air. Environmental conditions change a lot faster than the machine’s mechanics change, and those environmental conditions can have a big effect on the quality of your extrusions.
Ambient temperature can also make a difference, particularly for overhangs. And that changes as fast/frequently as humidity.
@RMB : Thank you so much for the tips. I don’t think that printing speed is the problem here. Before you replied, I started a print with random seams. You were absolutely right about the ugly dots all over the surface. But the corners came out good. Even in the print in my initial post, the corners on the other side came out significantly better.
However, your second tip seems to fix it. I did a test print with two parts at once. I left one part at the default print speed and reduced the speed for the second part. Both parts printed really nice. The slow speed might produce minimal better corners but I like the surface of the normal speed part better. I will start the print with two parts at original speeds. Thanks again.
@RocketSled : Thank you, too. I do not have a drybox, but I’m aware of this problem. I do store the filament in a plastic bag with some silicagel when I’m not printing. I already ordered the parts to build a drybox out of an IKEA Samla box.
However, I don’t think that moisture is the problem here. The defects were consistently at the seam position and there is no stringing. Furthermore, a different part I printed the same day with the same filament was perfect.
Is it possible that the artifacts were “away” from the sider chamber fan (or at least, not receiving air from it)? If so, you could try orienting the side where it can receive air.
If this resolves the issue, then it would seem as though some overheating is happening. Although it is often said to stop/slow down the nozzle fan when printing ABS, you might need to have a bit more cooling happening just the same.
Moisture in the filament messes with flow rate and pressure advance. If the filament is really wet, it might be impossible to print. But blobbing on seams will happen even with moderately wet filament. In the time it takes the extruder to move to the starting position for the outer wall, some filament is extruded because of “steam pressure” and that blob gets wiped from the nozzle and deposited at the seam the moment it makes contact to start the next layer.
