Nubby h2.0 - #make5000

This is an alternate nubby cover design for extra traction in water.
(Note: I did NOT copy from the sphere waterball housing or sphero paddles. I had this almost entirely though out before i even saw them)
I am working on an alternate model for use with 3D printer material. the final product can be made out of silicone like the original nubby cover.
@orbotix / @gosphero I don't know what license to use for this design so i have "creative commons-attribution-noderivitives" checked,