Cam Size
Terminology that relates to 'CamSize'.
•  Base Circle: the diameter of the smallest circle that is tangent to the cam surface. 
•  Prime Circle: the diameter of the smallest circle that is tangent to the . 
•  Cam Lift (also called Follower Stroke): the difference between the 'PrimeCircle' and the maximum radius of the PitchCurve. 
Advantages of a 'smaller' Cam.
A small cam:
•  reduces material costs (but a 'very' small and 'very' large cam increase manufacturing costs). 
•  reduces its inertia for rapid starting and emergency stopping. 
•  reduces outofbalance forces. 
•  reduces the numberofrotations that camfollower roller makes for each rotation of the cam 
•  reduces the angular velocity and angular acceleration of the camfollower roller 
Disadvantages of a 'smaller' Cam.
A small cam:
•  reduces the flywheel effect. This helps to rotate the camshaft at constant angular velocity. However, this effect is usually quite small. 
•  increases the accuracy required to manufacture. 
Cam Size and the MeasurementDimension FB

To measure the Cam with a Measurement FB, we will click different Points.
If necessary, to select Points only, use
Basic Circle
The radius of the BaseCircle is the minimum radius from the centre of the cam to the contact between the cam and the camfollower.
2.  Click the small Point at the contact between the CamFollower and the Cam 
3.  Click the Point at the centre of the rotating Cam 
4.  Click the graphicarea. 
The Measurement [and the FB] are now in the graphicarea . The Measurement will increase and decrease when you rotate the cam.
When the Measurement is a minimum  you have found the radius of the BaseCircle
Cam Lift
The difference between the minimum and maximum values given by the Measurement FB is the CamLift.
You can also use a Stats FB to find the maximum and minimum values.
PrimeCircle (also called the Reference Circle)
The radius of the PrimeCircle is the minimum radius from the centre of the cam to the centre of the camfollower.
1.  Click Add Measurement FB 
2.  Click the Point at the centre of the Cam and then the centre of the CamFollower. 
