TABLE OF CONTENTS First, a clarification the word cam in this chapter refers to a specific type of design within the field of mechanical engineering it does not have anything to do with the video type cams or even the CAM part of CAD/CAM. The focus will be on the developing a part program for a typical cam.
In geometrical terms, a typical cam can be described as a special contour profile that contains a combination of arcs and splines. In mechanical terms, the main purpose of a cam is to transfer motion as a typical example, a rotary cam motion can be transferred into a linear motion. Common cam mechanism will have two moving parts attached to a single fixture (frame). The moving parts can be curved or grooved and they work in conjunction with a follower. The follower will cause a series of single motions (called events) to take place, while the cam is completing one cycle.
There are three events in a single cam cycle that the follower will provide:
Rise
Dwell
Fall (also called return )
All three events are related to the following activity, relative to the cam center:
| RISE | ... follower motion away from the cam center | (also called positive motion) |
| DWELL | ... provides no change in follower motion | (follower is idle ) |
| FALL | ... follower motion towards the cam center | (also called return or negative motion) |
Cams are frequently used in many industries, particularly in automation machinery, gear cutting, screw...
