[EricH]

Originally Posted by Koosley

He also mentioned that those props we were using are so strong that its actually illegal to make props bigger than 16 inches (somewhere around here) out of that material, and he was saying how the only thing that would break them would be foreign objects coming in direct contact. He said that sudden changes in force due to collisions would have no effect on them or cause them to break and same with vibrations. He also mentioned that little objects like nuts and bolts and washers probably won't have to much effect on the prop its self, but its best not to find out (it may just turn that nut into a bullet).

As for the safety part, we are planning on having 2 cages, the first one as shown on the first page, will be used to keep large objects (mostly orbit balls) away from the props, then inside of that cage will be the aluminum housing and mesh.

I've seen props made of carbon fiber break. That's pretty strong stuff, right? Especially if it's done right, and the company that makes them does it right. And they still break. There is, for safety consideration at any rate, no such thing as an unbreakable prop. Same goes for wood. Those plastic ones that you show? I've seen plastic ones break too.

Also, if you have the aluminum housing and mesh, you probably won't need the outer cage. It's a very good idea, though, as it adds a second line of defense against various things getting into the prop.