Make it Rotate

I made this device to be able to rotate any small object or 3D print with a variable speed controller. Easy to build and requires no soldering or electronic experience.
The video will explain how it works, how to assemble, and list some possible ideas to rotate.

https://www.youtube.com/watch?v=ki4FqiUxBRA

2 AAA battery holder: http://www.ebay.com/itm/Battery-Holder-2-AAA-By-Radioshack-270-0398-New-/151936853974?hash=item23602467d6:g:ZusAAOSwyQtVmDEt

DC voltage controller: http://www.eb