Variation of Rotary Piston Drive 329

THE DESIGN HAS BEEN UPDATED. PLEASE SEE THING 1098809

This is a variation of an earlier post such that the piston is moved horizontally instead of vertically. This makes it much easier to demonstrate.
This part was designed in MOI and made from Diamond Age PLA on an Ultimaker original.
See it in action here: http://youtu.be/sjeND0kd6DM
or for a Blender animation see here: https://youtu.be/nthBsH_h0_E
For all the other parts please refer to: http://www.thingiverse.com/thing:614962