Customizable MPCNC mount for round tools

This is a customizable tool holder written in OpenSCAD to attach round tools to the [Mostly Printed CNC machine (MPCNC) ver 525](http://www.thingiverse.com/thing:724999). **It has not yet been tested** because I ended up finding [a Thingiverse mount for my exact tool](http://www.thingiverse.com/thing:1645698) (a crappy Harbor Freight cutout tool). It's designed to make multiple holders for a single tool that has varying diameter across its length (such as the aforementioned Harbor Freight piece of crap). If your tool is a uniform cylinder, you can simply print multiple copies of the same mount (and skip most of the instructions below).

I'm not turning on the Thingiverse Customizer because you honestly need to OpenSCAD open to iterate quickly repeatedly and to see the echo output from the script.

**If you use this model, please let me know if it worked! If you improve on it, let me know so I can link to it here.**

Instructions:
1. put the tool's biggest diameter into td
2. h