Customizer base piece for Rukey's V.2 Tripod Head

This is the very bottom piece in Rukey's awesome tripod head. Basically, we had a tripod where the entire head broke off, so we were left with a perfectly good tripod with a blank shaft pointing up. I remixed Rukey's incredibly versatile OpenSCAD code for this one piece so that we could dial in the exact parameters for our tripod's dimensions. It wasn't hard to imagine there would be other people out there who might have a similar need, so I figured I'd go ahead and add some controls for Custo