In power-transmission tasks, the mechanical designer faces sometimes the problem of transmitting a constant angular velocity from a shaft at the output of a motor to another shaft connected to the load. When the first shaft is connected to the rotor of the motor via a gear box directly, and the motor is supplied with an effective speed control system, then the problem of power transmission can be readily solved using a spur-gear train if the shafts are parallel; a bevel-gear train if the two shafts intersect; and a gear train with skew axes if the shafts are neither parallel nor intersecting. However, instances occur in practice whereby the rotor of the motor is connected to a speed reducer that does not preserve the constancy of the motor speed, e.g., when a sprocket-chain transmission is used. In these cases, the input speed is not constant, but periodic. This paper focuses on the design of a transmission mechanism that serves to rectify the periodic speed of an input shaft to deliver a constant speed to the load. Moreover, in doing this, we show that it is possible to reduce the speed delivered by the motor as well. The problem of power transmission between parallel axes was reported in an earlier paper. Here, we report work on the corresponding problem when the shafts intersect. In the two cases, a transmission based on cams is synthesised, this paper reporting on a design based on spherical cams.