I just got the ball cup from the Donkee spinner. It isn't that great.. without the rubber piece it won't hold the ball that well. I thought I could just line the edge with some black tape or some other tacky material.. it won't work.. the cup is way to big without the rubber piece that is supposed to go in it. So with the piece it might be better but I don't know..
I bought some rubber mat that I am going to secure to the inside and see if that works.

It might be cheaper to go to an auto parts store and purchase some trunk weatherstripping.

Hi, i'm from Canada and am looking for a ball spinner , prefer to make my own. It seems after reading the forum many say that they built, got plans via this or that , but did anyone ever provide you with them. I read the forum checked most repliers posts and was unable to find any. If you did receive any do you think that you could send them along my way, if you would I would be very greatful.--------------------best regards Peter

A spinner isn't hard to make.. I have a vortex spinner but I understand.. what you need..

What you are looking for a water pump electric motor I believe?! You need a belt and a few drive shaft wheel to connect them all together. As for the ball holder, you can use a flower pot or custom make one. Then you can either get a bigger flower pot to use as a splash guard or use a tub to do your work in.

Then you would need wood or metal to make the fixture of how you want to mount everything for stability.