A wall mounted base plate contains central shaft for cams to rotate around and a dial gauge indicator is used to determine the rise, dwell and fall of follower movement. Cams are rotated by hand.

The angular position of the cam is shown on a protractor and a pointer. Four interchangeable cams and two followers are also provided compare the linear change with the rise and fall of the follower.

A set of cams are supplied as standard along with a set of followers which run on the perimeter of each cam. Each cam can be easily changed and the angular and dial gauge readings are clear.