herringbone rack and pinion (double sided - interlocking with base) 28byj-48 mini stepper

the rack and base should be printed at 1.1 scale for better results, made to fit on 1/4 inch thread rod.

https://www.thingiverse.com/thing:874502 might be a good upper half for this

https://www.youtube.com/watch?v=daDDdXD-vpA << video of it spinning as fast as it would self start without ramping , i tried the bipolar stepper hack for these little motors and they lost torque. just use the drivers they came with.

-http://www.thingiverse.com/thing:336556 borrowed the doublesided rack from here... i couldnt seem to mirror the old one properly without a fuss.

http://www.instructables.com/id/Low-Cost-Hobby-Servo-XY-Table/ non related but these little motors could be a nice fallback if my ramping plan falls through for these little steppers.