That's great thank you, it explains a lot. I'm working on The Roasting Dish of Doom as a starter project but behind messing around with that I'm looking at building something serious for 2014 and FW Champs. I'm half way through sorting out a Pussycat type weapon but more 2WD and invertible with a fast chewing weapon to snag/pull/rip stuff off. But I was looking at these types of robots and the successful people on here seem to be the people that understand the physics of spinners, flippers, and designing for performance from the outset.

I knew that converting a roasting dish into a robot was never going to be a massive winner, but I have an extremely good idea about the basics needed to survive the FW Champs. I've spent hours on Youtube watching the fights and I understand now why people put drives where they do, how all the flippers have a similar geometry, how the spinners and drums use similar principals etc.