In talking to an engineer friend recently, we started discussing potential hoop design improvements. I think this could be a revolutionary design, though who knows if the tooling costs could ever be recouped.
Plastic:
According to my engineer friend, polypropylene is sort of a junk plastic and polyethylene is essentially wax. He mentioned that Polypropylene has tendency to crack and shatter, which I’ve seen to some extent in PSI hoops and hoops made of polypropylene. Polyethylene tends to kink as one would expect wax to. You’ve probably heard stories or seen regular hoops kink if you haven’t kinked one yet yourself.
Polycarbonate is a much stronger plastic with a greater range of elastic deformation, meaning it’ll return to it’s original shape when pushed too far. Polycarbonate also has a greater strength to weight ratio. I know Patrick from PSI hoops has been playing with Polycarbonate hoops but the one I tried felt uncomfortably stiff to me. I’m fairly confident it was 1/16″ wall polycarbonate tube. That said, it was amazingly light and the damn thing felt nearly indestructible. After speaking to my engineer about this, he recommended just finding a thinner walled polycarb tube. My internet searches have thus far not turned up polycarb tubing thinner than 1/16″.
We also discussed many other plastic options such as Delrin, Nylon and more but he seemed to think polycarb would be the way to go for lightweight, durable and affordable new hoop design.
I’m thinking the ideal design may be 1/32″ polycarbonate custom extrusion.
Profile:
That lead me to start researching custom extrusions. Well, if you move to a custom extrusion, there’s no necessity of staying round, so may as well design the profile for the characteristics we’d like in a hoop.
When we think about the forces that we apply to a hoop, the strongest forces generated come from rapid reverses and similar acceleration. If we were to think of the hoop as a plane, rarely do we apply strong forces that would fold the plane in half. This can be seen by the fact that all kinks that happen during hooping happen along the same access. Kinks pretty much all look the same.
This means that we’re wasting plastic and thus weight on one axis that could be applied to another. You can see in my design below, the profile is longer in one direction than the other. This would reinforce the weaker of the two axis.
Having a flat design serves would allow for greater wind resistance and would help the hoop fly flat, almost like a frisbee. I couldn’t guarantee it but that could potentially facilitate cleaner planes.
And lastly, this profile would give greater grip to the hoop. Imagine trying to perform a dynamic stall with this profile. The death grip needed on a regular hoop wouldn’t necessary.
So who’s ready to build me one?
