Snap Motor Mounts

These are geared attachments that "snap" onto the EV3 Medium Motor.
Or, you could affix these parts to the robot and "snap" the EV3 motor onto the LEGO part.
In either case, the purpose is to quickly attach and detach the motor and movable parts.

Using 4x4 Open Brick

Using Toggle Joint

Using 5x7 Open Beam

Using U-Connectors and 1/3 connectors

Using 3x3 T-Shaped Beams

Using Toggle Joint with Beam