It is often the case that a motion is designed for a Tool, but the Tool is not driven directly. A different Part drives the mechanism. The motion and forces are transmitted through the mechanism from a Driving-Part to the Tool-Part.
Usually, with a Cam mechanism, the Driving-Part is an oscillating Cam-Follower that is moved by a Cam.
There is also the case in which the Driving-Part completely rotates, but with a non-uniform rotating speed. This is a special-case. To make sure this can happen, the Driving-Part must be exactly the correct length.
The Driving-Part becomes a Crank that rotates continuously in one direction as the Tool-Part moves with your motion-design.
This is one application of the Continuous-Crank FB.
STEP 1: Add the Continuous-Crank FB to the graphic-area
The Continuous-Crank FB is now in the graphic-area and Assembly-Tree.
STEP 2: Open the Continuous-Crank dialog-box:
The Continuous-Crank dialog-box is now open.
STEP 3: See Continuous-Crank FB dialog-box