About this 3D model

I have been moving my clock designs in a steampunk direction. In keeping with that mentality, I decided the time-setting knob should also be steampunk-ish. I couldn't find anything decent around, so I took to OpenSCAD to design one... This design is to have a 1 to 2 inch diameter sphere glued in the middle. I will be using a 1-inch Uranium Marble, and lighting it with some UV to make it glow green-blue.