About this 3D model

I liked timschmidt's bolt hobbing tool for lathes, but [my mini lathe](http://www.grizzly.com/products/7-x-12-Mini-Metal-Lathe/G8688) can only handle tools that are 5/16" at or smaller. So I shrunk the shaft small enough to work on my 7x12 mini lathe. Video of it being used: [http://www.youtube.com/watch?v=4tgy6EqJs_0](http://www.youtube.com/watch?v=4tgy6EqJs_0) Video of a sample resulting hobbed bolt: [http://www.youtube.com/watch?v=j4hURhqCc9I](http://www.youtube.com/watch?v=j4hURhqCc9I)