Fanuc DC axis motor models from Fanuc are yellow capped and precede the later generation AC servo motors. The DC M series is driven by the first series of transistor based velocity control units. These M series DC axis motors were introduced at the end of the 70’s and were fitted onto machines dating to the late 80’s. Models include Fanuc 00M, 0M, 5M with tapered shafts and 10M, 20M, 30M predominately with straight shafts and without brakes, though some large models do have brakes. Feedback is either tacho based or encoder based, in which there were 3 different speed pulse coder units fitted.