This is my OpenJSCAD attempt at creating a parametric design for the roller (lantern?) rack and pinion. I originally was attempting to use the following thing: http://www.thingiverse.com/thing:18110 Upon further review, this object and code didn't work as desired. This thing would cut each tooth as a separate object, and then line them up (with no overlap) for a union. My design can be found on github: https://github.com/g19fanatic/roller_pinion_rack This cuts the rack using the pinion as one whole object. It does take quite a while to cut and I like to do it from the command line so that the GUI doesn't lock up. I've included three printable objects here. One rack ,one matching pinion and one rack joiner. Use the joiner to align multiple segments of racks to keep linearity across the whole line. Please feel free to head on over to github if you'd like to make changes to the jscad file. More the merrier tbh...