This mounts on the right side of the MakerBot Cupcake where the endstops used to go. You can create and attach anything, as long as it uses a matching hole pattern (see instructions).

The teardrop-shaped holes are my attempt at being clever to solve the overhang problem while printing horizontal holes.

Mount with two M3 bolts and nuts in the two holes on the right side of the Cupcake that are 20mm apart.

The centers of the holes on the top of the mount are as follows:

Base holes: M3, 20mm apart.
Top hole: M3, 5mm vertically from base holes.