Hi Tim,
I have been working with Kev on this, and at our last discussion at the FRA meeting, we discussed a method of determining the max rpm of the system. It was suggested that, as it would be dangerous to get close to a spinning disc to measure it, the output shaft attaching to the disc should be tachod for the rpm. not only will this eliminate the need to work out gear ratios etc, it has the side effect to factoring in losses and inefficiencies as we are getting output rpm not input power.

The things kev and I are investigating are to allow spinners to run, and although its unlikely the final solution will be 100% acurate for every spinner, it means they can come and play, so if we are talking about 5 or 10% inaccuracy, thats better than staying at home. As the live circuit gains experience in running spinner, Im sure further developments can be made to get closer to exact figures.

Hope this helps.
James