I have an STL of the gear arm posted on the inverted delta thread (it's why I revived it). It uses the second type of chamfer as it does eat up less of the gear and I figured that was more important than the angular look I liked of the first one, especially since the gear ended up narrow than expected.

I have since done a slight redesign of the gear arm to slim down some parts, add some mounting holes I'd forgotten and add some clearances for the things that go in those mounting holes I forgot. It looks a little sleeker now and will use a bit less material. In the end I'm hoping to design it with 'struts' built into the model so it can be printed with 0% infill and be strong enough.

It came to mind that infill isn't really optimized as in denser in high stress areas, or orientated with how the loads will be. As such I'm trying to make it s the part can be printed hollow and the walls of all the struts provide all the strength necessary. Currently working on the shoulder, which turns out is a bit more complicated than I thought in terms of getting it printable without supports (mine differs from the original, notice how there is no place to mount the motor on the arm (that's not one of the things I forgot) ?).