Printrbot Play Riser Feet

I wanted to print some feet to raise my Play up a bit to allow wires to go underneath. I've seen designs that use flexible filament, but I don't have any so I designed these to utilize small bouncy balls (~1" / 25mm diameter) from the dollar store and bolts/nuts to attach to the printer. I have two files, one designed for a 6mm bolt and one designed for a 1/4-20 bolt.

https://www.youtube.com/watch?v=pPyl5HwsVfk

UPDATE: I have since upgraded to the extended Y heated bed. The extra mass of the extended bed caused the printer to rock considerably more with the soft bouncy balls I used. If I could find some that were firmer, it may work better, but for the time being, I have removed these and am using the original rubber pad feet.