Dialog: Cam-Data FB

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Dialog: Cam-Data FB

Cam-Data FB > Cam-Analysis

2D-Cam - work-flow

1.Add a 2D-Cam - see Add 2D-Cam


IF the new 2D-Cam is a Conjugate-Cam or a Groove-Cam (or other Body-Closed Cam):

1.a. Add a Conjugate-Cam FB - see Add Conjugate Cam FB

1.b. Edit the Conjugate-Cam FB - add 2×flanks from 2×2D-Cams - see Conjugate-Cam dialog-box.


2.Select the 2D-Cam or the Conjugate-Cam as the Power Source for the Follower - see Configure-Power Source

3.Review the 2D-Cam : Display, Properties, Life, ... - see below

4.Add a Cam-Data FB - see Add Cam-Data FB

5.Edit the Cam-Data FB to link it to the 2D-Cam- - see Link the Cam-Data FB to a 2D-Cam

6.Connect wires from the Cam-Data FB to a Graph FB to analyse 5 parameters - YOU ARE HERE:

7.Edit the Cam-Data FB again to Calculate the Cam-Coordinates - see Cam-Coordinates dialog


How to Link a Cam-Data FB to a 2D-Cam

Double-click FB to open the dialog-box

Before you can analyze a 2D-Cam, you must link it to a Cam-Data FB.

See Cam-Data FB to add.

In the graphic-area of the Mechanism-Editor:

To open a Cam-Data FB:

1.Double-click the Cam-Data FB - or - See How to Open a Dialog-Box  

The Cam-Data FB is now open.


To link a 2D-Cam to the Cam-Data FB:

2.Click a 2D-Cam in the graphic-area or the Assembly-Tree

There is now a link between the 2D-Cam and the Cam-Data FB.


To close the dialog:

3.Click the MD-Cross-Close at the top-left of the Cam-Data FB

A 2D-Cam now has a link with a Cam-Data FB.

Now, you can connect wires for the output-connectors of the Cam-Data FB to analyze the 2D-Cam.


Cam-Data FB: Cam Analysis Parameters

Analysis Parameters from Cam-Data FB

Analysis Parameters from Cam-Data FB

The five output-connectors from the Cam-Data FB provide:

F   :  Contact Force : See Note 1

Ԏ  :  Contact Maximum Shear Stress : See Note 2

ρ  :  Radius-of-Curvature : See Note 3

μ  :  Pressure Angle : See Note 4

Ue : Sliding Velocity - see Note 5

Drag wires from the output-connectors of the Cam-Data FB to a Graph FB, a Math FB or a Statistics FB

Make sure you select the correct cam (Inner, Outer, Pitch-Center Path) in the Y–axis display option of the Graph FB interface.


Top-Tip:

Connect the same output-connector and parameter (e.g. Pressure-Angle) from different Cam-Data FBs to the same Graph FB. Then you can analyse the same parameter for up to 4 × 2D-Cams in one graph plot.

Set the Minimum and Maximum Values to be the same for all graphs. Then it is even easier to compare the same parameter for each 2D-Cam.


Note 1: Make sure to do Configure the Power Source.

If Contact-Force does not show in the Graph FB, even with the Power Source configured correctly, change the Cam from Inner to Outer, or vice versa, in the Graph FB > Y-axis Options.

Note 2:

Make sure to do Configure the Power Source.

If Shear-Stress does not show in the Graph FB, even with the Power Source configured correctly, change the Cam: Inner to Outer, or vice versa, in the Graph FB > Y-axis Options.


The Maximum Shear Stress is below the Cam surface. The Maximum Shear Stress is a function of the material properties of the contacting bodies

Material Properties:

Cam-Follower: ,

Cam: taken from the Steel Selection in the  Cam-Life tab of the 2D-Cam dialog-box.

There calculations have assumptions. The most significant assumption is that friction is zero, and the bodies are perfectly smooth.


Note 3:

By convention, the Radius-of-Curvature (RoC) of a Roller is positive.

When the cam is convex relative to the Roller, the RoC of the cam is positive.

When the cam is concave relative to the Roller, the RoC of the cam is negative.

Radius-of-Curvature of the Pitch-Curve is not available. If you need to know the Radius-of-Curvature of the Pitch-Curve, export the Radius-of-Curvature of the Inner and Outer cams to Excel, and calculate their average.


Note 4:

The Pressure Angle is through the center of the Cam-Follower. There are two other Pressure Angles available: the Contact Pressure Angle of the Inner and Outer Cams - these are labeled as Inside Cont. PR, Ang. in the Graph FB > Y-axis display options.

These should be used with a Flat-Faced Follower only.

We cannot calculate Pressure Angle for a Stationary Cam.


Note 5:

Use Sliding-Velocity to calculate the Film Thickness of the lubricating oil between the Cam-Follower and Cam. If you know the surface finish of the cam and cam-follower, then you can also calculate the Film Thickness Ratio. This is an important parameter to calculate as it strongly influences the life of the cam.


Sliding Velocity = (Velocity of Cam Surface - Velocity of Cam-Follower Surface)

Entrainment Velocity = (Velocity of Cam Surface + Velocity of Cam-Follower Surface) ÷ 2

Slip-Slide-Ratio = Sliding-Velocity ÷ Entrainment Velocity

tog_minusContact Force / Contact Shear-Stress