Hypercube Evolution pcb/protoboard mount

The Hypercube Evolution with twin Z drives has an extra 30x30 rail on two sides, on mine this is 105 mm below the top rail. This part allows two 50 x 70 mm protoboards to be fixed between the two rails. These are the cheap and cheerful boards for prototyping electronics sold on ebay.

The feet are copied from https://www.thingiverse.com/thing:1264391

Slightly reworked version of my Arduino Mega mount https://www.thingiverse.com/thing:2583345