Jet Engine Model Motor Drive

This is a motor drive for the GE "Build Your Own Jet Engine". It replaces the hand crank of the original.
I designed this to use a motor, switch and battery holder available from any RadioShack store.
The gearbox is a 243:1 speed reduction based on the design from "mirk", but shrunk to 50%. The drive chain and drive gears are based on the design by "peanut", only shrunk in width. I also had to re-draw both of these as Slic3r was messing up on the edited versions I originally tried.
##Build Instruction Videos:
http://youtu.be/eEZHopwp_uw
http://youtu.be/0vsQaENOMUE
http://youtu.be/94io_2Rzg4M
http://youtu.be/1e-gh9qcMAo
http://youtu.be/t0UVHZkPXHU
http://youtu.be/Mr3x3RQa9MQ
http://youtu.be/Dw0kpxK5sPE
http://youtu.be/cVXT8cPgXAs