Some of you will already have seen this in Blackrock last year. I've entered this for the Reverse Engineering Challenge in Railbricks 9. Unfortunately there was no mention of the REC in the latest issue so I've decided to put this online now.
PF points motor by Duq, on Flickr
The inspiration is mentioned in the picture. The beauty of my design is that it doesn't pull itself apart. The only risk is leaving the motor turned on...