Uses a postman’s elastic band and a ratchet mechanism to allow it run on when the band has lost all tension. Did not fair too well in the club race on the 21st June 2008. Too much energy was lost in friction because of the 1:10 step-up ratio. Other models twisted the band to give a direct rotary motion, and seemed a lot more efficient.
This is one of the worst models I have ever made. Do a Secretary’s Challenge because you like the challenge, do not do it just for the sake of it.