VEX motor to Tetrix metal adapter

I'm using this adapter to implement VEX 393 2-Wire motors on an Arduino-powered robot, called (wait for it) ... the O-bot! I've mentioned this robot in one of my previous designs, and I plan to upload pictures of all of the 3D printed parts on the O-bot and the bot itself once it is completed.

UPDATED: The original design had one major flaw: the area where the screws attached the motor to the mount itself was insufficiently connected to the base, resulting in the motor tearing itself off of t