Unless you are using the wheel just for fun, don’t buy the cheap ABS plastic wheels you’ll find on Ebay. There are many other brands, but these are the most common. The most common wheel designs are John Huxley, Cammegh and Abbiati.
The full size of a roulette wheel you would find in casinos is 80cm straight across the middle. Different wheels can produce very different spins. If you don’t carefully consider the advice, you can end up buying a wheel that’s nothing like real wheels in today’s casinos, except that it “looks” much the same.
This article discusses everything you need to know about buying your own professional Roulette wheel.