Here is version 1.0 of my molded quadcopter leg. It's custom fitted to mate directly to my quadcopter motor mount found here:
http://www.thingiverse.com/thing:128477

This version is a bit desiel but will hold up to just about any abouse you plan.

Checkout the full build over at http://backyardrc.wordpress.com/

https://backyardrc.wordpress.com/2013/08/13/3d-printed-quad-build/

And checkout the complete series of BackyardRC's Quadcopter parts on Thingiverse:

Want one of your own Quadcopter molded leg printed for you? Or another design on thingiverse?? Contract my printer with 3D Hubs and I'll print, pack, and ship you your part within a few days!!

Check it out: http://www.3dhubs.com/harrisburg/hubs/mark

Center Hub: http://www.thingiverse.com/thing:136209
ESC Mount: http://www.thingiverse.com/thing:122363
Motor Mount: http://www.thingiverse.com/thing:128477
Quadcopter Leg: http://www.thingiverse.com/thing:136208
Ardupilot top plate: http://www.thingiverse.com/thing:136213