The Objective of this Step:

To calculate the Cam-Coordinates

Summary of this Step:

This step will:

1.Add a Cam-Data FB
2.Link the Cam-Data FB to the 2D-Cam
3.Plot the Pressure Angle of the 2D-Cam with a Graph FB
4.Use the Cam-Coordinates FB to calculate the Cam-Coordinates

tog_minusVideo of this Step


Tutorial 6A-8


tog_minusAdd a Cam-Data FB


STEP 1: Click Add menu > Add Cam-Data FB
- or -
Click Kinematic-FBs toolbar > Add Cam-Data FB
Cam-Data FB in graphic-area

Cam-Data FB
in graphic-area

STEP 2: Click in the graphic-area

The Cam-Data FB is larger than other Function-Blocks.

It has five output-connectors.

We must link it to a 2D-Cam.

tog_minusLink the Cam-Data FB to a 2D Cam


STEP 1: Double-Click the Cam-Data FB that is in the graphic-area

The Cam-Coordinates dialog opens.

The image shows the open Cam-Coordinates dialog.


STEP 2: Click the 2D-Cam that is in the graphic-area
- or -
Click the 2D-Cam in the Assembly-Tree.

The name of the 2D-Cam shows in the Selected Cam-Track box

STEP 3: Click OK-tiny-11-15 to close the Cam-Coordinated dialog-box.

To open the Cam-Coordinates dialog later:

Double-click the Cam-Data FB again,

- or -

See 'How to open a dialog-box'

tog_minusCam Analysis - Pressure Angle

Cam Data FB output-connectors [Note: Entrainment-Velocity is available from R14+]

Cam Data FB output-connectors
[Note: Entrainment-Velocity is available from R14+]

There are five output-connectors from the Cam-Data FB (R14+) - see image to see the output from each output-connector.

A Profile/Extrusion element is one way we can add mass to a Part. However, the only Profile in the model is the Cam-Follower Roller, which will not have a large mass. Also, it does not represent the distribution of the Mass in the Cam-Follower System. Thus, in this tutorial we will not analyse the Contact-Force or Contact-Stress between the Cam and the Cam-Follower.

We can however, analyse its Pressure Angle and Radius-of-Curvature and Entrainment Velocity

STEP 1: Drag a wire from the Pressure-Angle output-connector to a Graph FB

The Pressure-Angle of a Cam is an important parameter analyse. A high Pressure-Angle, means that the force is not transferred from the cam to cam-follower very efficiently. The Pressure-Angle imposes extra forces on the machine elements in the cam and cam-follower systems. The forces increase rapidly once the Pressure-Angle becomes greater than 40° (an arbitrary angle as it depends on what is being driven by the cam). Many designers aim to keep the Pressure-Angle to less than 30°.

See: Cam Analysis and Checklist for further information.

See Tutorial Forces 13 for force analysis.

Tutorials and Reference Help Files for MechDesigner and MotionDesigner 14.2 + © Machine, Cam, Mechanism, and Motion Design Software by PSMotion Ltd