On Tue, 17 Apr 2012 09:27:48 +0100, Dona Ferentes wrote:

I think, however, that you will struggle to achieve sufficient rigidity
with tennis balls.

Possibly. An additional thought I had after posting would be to make
slits/crosses on opposite sides of the ball and have the cane ends
pass right through. Might need so careful plotting of where to put
the slits so the canes can cross inside the ball.

--
Cheers
Dave.