We are looking for new ways to create a compact solution for moving the axis of a CNC machine. This is one of the concepts.
The main idea is that the threaded rod is still (it does not rotate). Instead, the nut is the one that rotates.
Please check out the video: http://www.youtube.com/watch?v=gZ7W4M-OSXI
This object would require some redesign to fit your application. I have uploaded all the OpenScad sources.