Prusa i3 Bowden Hotend mount with radial fan and a parametrizable inductive proximity sensor

The hotend mount ["Prusa i3 Bowden Extruder + Inductive Proximity Sensor + Radial Fan"](http://www.thingiverse.com/thing:723803) is great but has a slot for a 12 mm sensor whereas my sensor has 18mm diameter. Therefore I created this OpenSCAD design which enables you to **customize the mount for the proximity sensor**. You can change the mounting plate dimensions and the hole diameter any way you like. The default settings produce a mount for 18mm proximity sensor which is also available as an S