Summary

i have 2 8mm threaded rods on my mendel max.
so i adjusted the original design to fit my needs.

the motor side shaft are 5mm

Instructions

print
drill the holes for the cube with a 3mm diller
mount the motor using a M3 nut and Screw
drill the rod in the threaded rod mount piece (you can also glue it)
place the cube in the middle of the motor mount and put some 3mm filament through the holes of the mount and the cube
place the threaded rod mount with the rod at the top turned by 90 degrees and put some more 3mm filament through the holes of the mount and the other holes of the cube - for the top mount you have to place two pieces - one at each side (because the hole is blocked at the middle from the motor mount filament going through the cube)