Quote Originally Posted by kane
I don't think any event organiser without a secure roof on their arena would take the risk. Even a relately low speed spinner could throw a lot of shrapnel. As much as an audience love the action, they wouldn't like to be part of it!
You say that, but both EO's now have a robot with a spinner running in their arenas (Matilda and now Goliath). I don't know what speeds they are doing but as you said, potential risk at any reasonable RPM.