[Steve_Alaniz]

Red that looks like a potentiometer sounds like this part number:

EM14C0D-E28-L064S

From digikey

It's only 64 counts per rev but a complete package.

( If you are adventurous and can build your own interrupter wheel... or HAVE an interrupter wheel look into the honeywell HOA0901 which is an all inclusive dual channel digital detector with both phases in a single package. It doesn't need to be aligned and doesn't use a 4 equal phase scheme so a small number of interrupts doesn't work well, but I tested it with 8 interrupts and it seemed to work. Not accurate enough for an inkjet printer but probably accurate enough for any FIRST application you might have.)

But... I digress...

Steve Alaniz