Calculate The Point of Contact Between Cam and Follower

Determining the exact point of contact between a cam and its follower is crucial for mechanical design and analysis. This calculator provides precise calculations based on standard engineering principles, helping engineers and designers ensure proper mechanical operation.

Introduction

The point of contact between a cam and follower is a critical parameter in mechanical engineering. It affects the transmission of motion, force, and energy between components. Accurate calculation of this contact point ensures smooth operation and prevents mechanical failures.

This guide explains how to calculate the contact point between a cam and follower, the factors that influence this calculation, and how to interpret the results.

Formula

The position of the follower along the cam profile can be calculated using the following formula:

θ = arccos[(r - y) / R]

Where:

θ = Angle of rotation (radians)
r = Follower radius
y = Vertical position of the follower
R = Base circle radius of the cam

This formula assumes a circular cam profile. For other cam profiles, different formulas may apply.

Calculation

To calculate the point of contact between a cam and follower:

Determine the base circle radius (R) of the cam.
Measure the radius (r) of the follower.
Identify the vertical position (y) of the follower.
Apply the formula θ = arccos[(r - y) / R] to find the angle of rotation.
Convert the angle to degrees if needed.

The result will give you the exact position where the follower contacts the cam.

Example

Let's calculate the contact point for a cam with the following parameters:

Base circle radius (R) = 50 mm
Follower radius (r) = 10 mm
Vertical position (y) = 30 mm

Using the formula:

θ = arccos[(10 - 30) / 50] = arccos(-0.4) ≈ 1.982 radians

Converted to degrees: 1.982 × (180/π) ≈ 113.13°

The follower will contact the cam at approximately 113.13° from the reference position.

FAQ

What factors affect the point of contact between a cam and follower?

The point of contact is influenced by the cam profile, follower geometry, and the mechanical properties of the materials used. Clearance and wear also play a role in the actual contact point.

How does the cam profile affect the contact point?

Different cam profiles (circular, flat-faced, etc.) use different formulas to calculate the contact point. The circular profile formula provided is just one example.

Can this calculation be used for any type of cam and follower?

This calculation is specifically for circular cam profiles. For other profiles, you would need to use the appropriate formula for that specific cam type.