Actually, We originally used IME’s (Internal Motor Encoders) on the thrower. We ended up using the red encoder chained 1:2.4 from the flywheel axle both so we could sense the changes in speed faster, and so that we had more counts per second so that we could allow for more checks of the speed per second.
By having a quadrature rather than an IME, we where able to slightly increases our aggression, consistency and fire rate. Especially because we are mostly working with chain and sprockets. Here is why.
Between the gearing in the gearbox of the motor and the external gearing of the thrower, you have 7 or more compound gearing sets. Your IME only reads the first gear speed. This is where the discrepancy is hidden. Depending if you are accelerating or decelerating, your IME speed will shift up and down the actual value.
I would actually really like to graph the speed of an IME V.S. a quadrature to see the difference.