Just for interest sake, check out
http://www.usdigital.com this is the so called 10 dollar encoder company. They really sell a 10 dollar encoder, and it's good quality. I've used many, many of them, and in fact, Wescan (Linatrol) CNC uses them on their CNC controllers, I have sold their controllers coupled to flatbed CNC machines we manufacture, off course until I found Mach3, much, much cheaper. Just don't try to order the encoders from Linatrol, You'll pay 200 t0 300 dollars!
Whacko