Herringbone gears for ROBO 3D

Just moved the appropriate parts to a plate so they could be added to the robo group. Had a hard time finding a set that fit the robo. Since it has a non adjustable stepper, has to be the right size.
Reduced steps per mm about 250-300
Probably a better set available... but until it's posted in groups....

http://www.thingiverse.com/thing:46374
http://www.thingiverse.com/thing:5111

center nut holder on the large gear is a mm too small. not a problem with an exacto or something.