ABS is known to warp a lot, because of it’s high glass-transition temperature. Especially with low environment temperatures, the printed plastic shrinks and thus “warps”, meaning the sides get pulled up and the part lifts from the print surface. But did you know this can even happen mid-print? I noticed that small features like circles, holes or elevations don’t bond properly to the surface it lays on, making a weak connection.
Printers affected by this issue:
ABS is a mix of different polymers, so the individual properties of your specific filament might vary significantly from my own results. Especially open-frame printers will give you a hard time printing some brands of ABS. However, my findings should apply to most printing scenarios.
How to detect?
This issue is very easy to detect. After inspecting a printed part (Voron M4 extruder), I noticed that a small mating area could easily be bent away with little force. A small fillet is also clearly visible. I printed a random “retraction test” I found online, to do my investigations.
Dangers imposed by this problem:
Cracks in your printed parts are obviously never a good sign.
Finding a solution was quite tricky, because I did not notice any warping at all in the first layers and the “tower” seemed to start well! However, I disabled the part cooling fan for the first layers. I had mine running on 40%, if the layer time was below a threshold. That made the ABS plastic shrink a lot and delaminate from the previous layer.
After completely disabling the part cooling fan in the Slicer, the problem was reduced significantly. It’s not gone completely yet, however that could just be a cause of my big printing volume or some other settings. Changing the temperature only made a negligible difference, but against my expectations, lower printing temperatures worked better.
If you experience drooping of the printed parts, you might want to increase the “minimal layer time” to help the ABS plastic cool down before the next layer.