Yeah, Ive taken that into account, but the way that Micro-Maul evo 1 & Micro-Maul evo 2 are built means the top and bottom polycarbonate panels add to the twisting strength of the robot. Any hard hits will have to break the polycarbonate/shear a load of bolts to do anything.
I have seen that Alos only uses a carbonfirbre top, not designed for much structural strength. I guess the only way to test it is to but it against a load of spinners...

& thanks everyone, I have taken all of your comments into account with the finalised design of the disc.

Cheers, Ewan