I had some initial quality issues withe the 3D-printed pieces, but that was my fault due to the fact that I did not properly level the build plate. Doh!
The gear was made from one piece that I printed four times. The four pieces tabbed together to make the whole ring. I then sandwiched it between two rings of Sintra to make it more sturdy.
I 3D-printed a motor gear so that it would fit over the 1/2" Banebots shaft on my Jaycar YG2738 dome motor.
I have to say that I am very happy with the results, and the dome stops on a dime!
You can see a video of the dome drive in action also on YouTube: