Having completed my machining exercise, I fitted the rotary encoder to the motor and had a play.
First thing was to check the encoder even produced any output (I could have broken it). I added 5V and plugged A & B into the CRO. Two lines at 0V... not good. I touched the shaft, and the lines wobbled. Yippee! So I powered the motor via an adjustable supply, to see what it looks like when running.
Things learned:
* My 36V motor will turn with just 0.5V applied (that's cool)
* At very slow speed with no load, the motor has some serious cogging
Next... plug it into my servo controller.