Captive Planetary Gear Set: parametric.
thingiverse
To enhance an existing design found at http://www.thingiverse.com/thing:53451, I added axial holes in the planets as it was required for a gear set application. Additionally, I modified the shaft type from hex to the more common round with a flat. Despite my first attempt using SCAD, the design proved functional. This fully parametric design can be customized via the app: http://www.thingiverse.com/apps/customizer/run?thing_id=138222. I personally hand-edited the scad file for these improvements. Feel free to adjust it using the provided link.
With this file you will be able to print Captive Planetary Gear Set: parametric. with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Captive Planetary Gear Set: parametric..