Key cutting

Most of you have probably seen a key cutting machine before so I wont bother explaining what they are and how they work. As far as I can see, making one would be pretty easy, there is one problem I cant come up with an answer for -- The cutting wheel. I cannot think of anything that could work as a substitute for one of these.. so if anyone has an idea...

I believe you could probaly buy cutting wheels on ebay as you can buy the machine.Maybe dremel wheels

[Frester]

Well this is where I'll start anyways! Thanks!