Wobbler Engine
thingiverse
Watch this YouTube video for a helpful tutorial on obtaining 0.5 inches of material for all the required parts: http://www.youtube.com/watch?v=yNW0m6YCkxA&feature=youtu.be. For the two ball bearings, look in an inline skate. Please feel free to message me if you have any questions. My English isn't perfect, so please excuse any mistakes.
Download Model from thingiverse
With this file you will be able to print Wobbler Engine 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 Wobbler Engine.