I had troubles getting the M3 nuts into the original design by Villamany so I thought I should cut off the plastic "pillar" parts on the button and power jack part.
There's more to this motor adapter than just this part, but please check out the original upload by Villamany! http://www.thingiverse.com/thing:196482
Please also check the original-original design by MarkBenson http://www.thingiverse.com/thing:144333
That is where both my remix and the remix by Villamany comes from.
28mm Motor adapter for Mini Drill Press from MarkBenson by chrisfredriksson is licensed under the Creative Commons - Attribution - Share Alikelicense.