[apalrd]

To get to the disc, pull off the plastic housing on the back. It is the silver disc pressed on to the output shaft, mounted close to the circuit board. If you turn it on with the back off, a red light should light up the disc. Pull it off, and check to see if there is anything on it. Make sure the side with 360 lines is facing in, that could be a problem if it isn't. Clean it off, and put it back on it without touching the side with the lines.

Assuming you are using 3:1 off a toughbox with kit wheels, your scaling should be set to 0.00166666666666666... go get to feet. I would recommend using 0.02 to get to inches in your scaling, because you will primarily be using them in Autonomous for distance calculations its much nicer to type in whole inches instead of fractions of feet. All of this assumes 1x decoding, divide that by the decoding type to get your scaling. You shouldn't need more than 1x decoding.