OpenSCAD Geared Nema 17 Extruder Block

Wade's original geared extruder block is too big to print on a makerbot.

I remade the extruder block in OpenSCAD so that I could then carefully downscale parts of the extruder block to make it manageable. (I was inspired by the guy who used OpenSCAD to "patch" the original STL to take a BfB hot end, but for what I wanted to do it seemed better to recreate the whole thing).