Ball Spinner Mods

[Timmyb]

Having had quite enough of trying to use the "Polish Your Ball" equipment, I set in motion a devious plan to modify the undersized bearing turntable that they supply with the ball sanding/polishing kit. The cup portion is only 3.5" in diameter, and if you get the ball spinning too fast, you'll launch it. On top of that, the cup was a hard plastic, so not a lot of grab. If you were trying to sand or polish, and your weight block was positioned up, any amount of RPM would shift the ball in the cup, and you'd end up working a portion of the ball you didn't want to. True to my nature, this is grossly over-engineered, but that's the machinist in me.

https://s24.postimg.org/8kr7phm8h/IMG_1401.jpg (https://postimg.org/image/8kr7phm8h/)

https://s24.postimg.org/64pebn45t/IMG_1403.jpg (https://postimg.org/image/64pebn45t/)

https://s24.postimg.org/t7fxat5n5/IMG_1404.jpg (https://postimg.org/image/t7fxat5n5/)

The cup is now a 6.5" diameter piece of Delrin, which is mounted to the original bearing plate. That has a piece of sheet rubber glue to it for traction. That is bolted to 12" x 12" x 3/8" 6061 plate. Cost me about $35 to build. Stable as all hell!

[Aslan]

Nice!

[imagonman]

So, where did you get the bowl at? A step by step would be nice. Am looking to do same thing with the little platform on the ball ring.

Thanks!

[LyalC52]

nice work, thanks for sharing

but unless that was a scrap piece acetal, it seems rather pricey

[imagonman]

nice work, thanks for sharing

but unless that was a scrap piece acetal, it seems rather pricey

huh???????

[Timmyb]

So, where did you get the bowl at? A step by step would be nice. Am looking to do same thing with the little platform on the ball ring.

Thanks!

Bowl was a cutoff end of a bar we had at work. Turned the bottom end, flipped it, and turned the OD and bore, with a taper on the inside of the cup. Took about an hour. It's fastened to the original bearing plate through the four holes that originally held the rinf it came with. 10-32 fits perfectly if you drill the bolt circle spot on, which I managed to somehow do in my basement. You will need to re-chamfer the plate, or a flat head cap screw will stick up too much. It's mounted to the baseplate with 1/4-20's (the holes in the bearing that I tapped didn't even need to be re-sized. They were perfect for that tap. I used adjustable furniture 1/4-20 legs on the outside corner to level. Had those laying around from another project. The rubber on the bowl was damn near the most expensive thing I bought!

Lyal, yes, if you had to buy the Delrin, it's not cheap, but it's so easy to turn. I could have used 6061, just didn't feel like filling up a whole chip hopper.