Below is a mechanical toy based on a CAM mechanism. As the handle on the eccentric cam is turned the top part of the egg shell lifts to reveal a face. The basic construction of the toy is also shown below. The flat follower moves upwards and downwards as the cam rotates. Although the design is simple it must be made accurately or the mechanism will stick.


A drop cam has been used on the toy below. The movement is different compared to the smooth motion of the eccentric cam. As the cam rotates the top half of the shell lifts at a relatively constant speed and then drops down suddenly.

A drop cam has been used on the toy below. The movement is different compared to the smooth motion of the eccentric cam. As the cam rotates the top half of the shell lifts at a relatively constant speed and then drops down suddenly.