Electronic CAM Lecture Notes
Concepts of CAM
The transformation one of the simple motion such as rotation, into any other motion is often conveniently
accomplished by means of a CAM mechanism.
A CAM may be defined as a machine element having a curved outline or a curved groove, which by its
oscillating or rotational motion, gives a pre-determined specified motion to another element with which it
is in contact, called the follower.
As the CAM rotates so the follower is made to rise, dwell, and fall. The length of time spend at each of
the positions depends on the shape of the CAM, and the speed at which CAM machine element is
moving.
Figure 1. Different stages of a CAM Operation
The Rise Section of the CAM is the point that drives the follower upwards, its profile determines how
quickly the CAM follower will be lifted, the Fall Section of the CAM is the part that lowers the follower,
its profile determines how quickly the CAM follower will fall. The Dwell Section of the CAM is the part
that allows the follower to remain at the same level for a significant period of time. The dwell section of
the CAM is where it is circular with a radius that does not change.
The CAM has a very important function in the operation of many classes of machine, especially those of
the automatic type, such as Printing Press, Shoe Machinery, Textile Machinery, Gear-cutting Machines
and Screw Machines.
Electronic CAM Lecture Notes
 Length of the time sped in RISE,
DWELL and FALL depend on the shape
and speed of the CAM machine
element.
 Also the shape controls the profile.
Figure 2. CAM Operation Lobe Lift Vs Time
In any class of machinery in which automatic control and accurate timing are paramount, the CAM is an
indispensable part of the mechanism.
The possible applications of CAM are unlimited, and their shapes occur in great variety.
Electronic CAM Lecture Notes
Electronic CAM using Servo Motors
 Master Axis
 Slave/Follower Axis
The concept of electronic CAM operation is identical to the mechanical CAM operation in a way that the
slave axis or the follower axis follows the master axis but unlike Mechanical CAM electronic CAM
operation is done by defining set positions of master axis and slave axis through CAM points. These CAM
points are the reference points for the Electronic CAM operation and could be understood as a set of point
which defines the positions for the Master Axis and Slave Axis. The Slave axis follows Master Axis
based of these CAM points. For Example- CAM point (X=0.5, Y=0.5) where unit is 1 revolution means
that when the Master (X) is at 0.5 Slave (Y) should go 0.5 turns.
0 Position/ Rev
0 Position/ Rev
0.5 Position/ Rev
0.5 Position/ Rev
Master Axis
Slave Axis starts when master is at
0.5 position.
Electronic CAM Lecture Notes
CAM Points Example:
Table 1:
Master Axis
Slave Axis
0.0
0.0
0.25
0.5
0.5
0.5
0.75
1.0
1.0
1.0
CAM Position Profile-Master Axis Vs Slave Axis
1.2
1
1, 1
Slave Axis Position
0.75, 1
0.8
0.6
0.25, 0.5
0.5, 0.5
0.4
0.2
0
0, 0
0
0.2
0.4
0.6
Master Axis Position
0.8
1
1.2
Electronic CAM Lecture Notes
Master Axis Velocity Profile Vs Follower Velocity Profile
V, Velocity
VMASTER AXIS
x0
x1
x2
 Time t
 Displacement x
Velocity Profile of Master Axis
Velocity Profile of Follower Axis
Electronic CAM Lecture Notes
Advantages of Electronic CAM using Servo Motor






Accurate
Flexible
Programmable
Faster
Smooth Operation
Less Expensive