Back to the ABS. Not sure if this is still the Hadron built, but I think somewhat it is. Because the FDM technology has its drawbacks - especially in my case the lack of support – will make me think a lot when building some specific shapes.
A sphere, in this case. 8 mm dia. I need a perfect sphere. Actually 20 of them, for this large ball bearing. The main problem is that the sphere has a real small initial contact with the bed, so when it’s halfway built it’ll roll off, while the extruder is still building it.
I tried to have a small patch underneath, I tried to build it on a pedestal etc. None of those worked.
I ended up building half spheres with a 1.7 mm hole inside, then I cut small pieces of filament and used it as a pin to locate the halves relative to each other. Later I used some abs diluted in acetone to glue them together.
Here is the end result.
And here is the finished bearing.