Rotary encoder & mount for Johnson motor

This encoder system is based on a motor I found at a surplus outlet and bought because it had a GT-2 pulley. It appears to be a 24 volt DC motor which happens to be good for my servo controller. Luckily the motor had a shaft on both ends which allows the encoder to push on directly to the 3mm shaft. There was no mounting attachments on the back of the motor and that's why the encoder mount pushes over the motor housing. I sanded the inside of the motor mounting surface for a better fit and used