the concentricity they spin at makes me cringe. though in reality it would probably take many hours to make balls oval in a cleaner like that. and even then only if you are using a heavy polish. when i use my cleaner half the time i don't use any cleaner at all. what's still on the pads is generally enough to give the balls a good shine.It's not worth building your own anymore. Amazon has them for 100-200 range. Here are 3, with the cheapest at $123 with free shipping: