I was wondering how to mount a small rotary encoder to a platform in order to measure how far a small treaded robot has traveled. We're using this tread/wheel set: We've tried epoxying the encoder shaft directly to the end of an extra gear wheel, but it broke off quite easily. I'm thinking about grinding down the encoder shaft until it can just squeeze into the axle hole of the drive wheel and then using the epoxy inside the wheel. It would then be driven off of the tread. Like this: However I'm not sure this would be the best idea, and other suggestions would be appreciated. Especially with keeping any assembly either coupled to the drive shaft or to a tread.
Note: Its for an EE senior project, and none of us have much experience with construction skills. Its going to be the platform for an automated robot on Aruino.