Kerfmaker (M5x20mm bolts version)

ccrumpacker's Kerfmaker use M4x20mm bolts, but I only found M5x20mm and M4x16mm bolts at my local hardware stores (Home Depot, Rona,...), so I remix it.

This version use M5x20mm bolts instead, there is also a [M4x16mm version](http://www.thingiverse.com/thing:1803005)