This is a simple longer version of chasmaker original smaller stepper gear. This one will not move on the axis and it is very robust. The picture shows it after 10 month of use and kilograms of PLA. No wear so far! It works very well with my big gear at http://www.thingiverse.com/thing:25501Sorry, no source code in the first place. I used meshlab to extend the gear! When I printed chasmaker' beautiful design in PLA (instead of ABS), I quickly found that it failed (because of my stepper heat on some tricky prints -- I was having feeding problems at the time). The benefits of this longer derivative are: