Step 7.3: Add Cam-Data, Measurement, and Graph FBs

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Step 7.3: Add Cam-Data, Measurement, and Graph FBs

Edit the Design-Set.

The objectives are to edit the four dimensions in the Design-Set, and

Make sure the maximum radius of the cam does not exceed :

Minimize the Pressure-Angles

We will use a Cam-Data FB and a Graph FB to plot the Pressure Angle and the Radius-of-Curvature* to find the maximum radius of the Cam.


Note: * We could also use a Measurement FB to measure between the the center of the Cam-Shaft and the contact-point between the Cam and the Cam-Roller.


Plot the Cam Radius of Curvature:

STEP 1: Edit the 2D-Cam to display only the Inner cam - if needed

1.Mechanism-Editor: Double-click the 2D-Cam in the graphic-area (or see How to open a dialog )

The 2D-Cam dialog is be open.

The two Cams use the labels Inner and Outer

3.Click 2D-Cam dialog > Display tab > Cam Visibilities >Inner

4.Click OK-tiny-13-17 to close the 2D-Cam dialog.


STEP 2: Add a Cam-Data FB and Graph FB to the graphic-area

GST-Icon-FB-CamData

1.Mechanism-Editor: Click Kinematic FB toolbar > Add Cam-Data FB

2.Click the graphic-area

GST-Icon-FB-Graphs

3.Mechanism-Editor: Click Kinematic FB toolbar > Add Graph FB

4.Click the graphic-area.

A Cam-Data FB and a Graph FB are now in the graphic-area.


STEP 3: Link the 2D-Cam in the model with the Cam-Data FB

1.Mechanism-Editor: Edit the Cam-Data FB to open the Cam-Data Dialog (or see How to open a dialog)

2.Mechanism-Editor: Click the 2D-Cam in the graphic-area (or Assembly-Tree).

When you click the 2D-Cam, the Cam-Data FB:

calculates the Cam-Coordinates automatically.

may change the 2D-Cam from Inner Cam to Groove Cam (Inner and Outer)

3.Click the Cam-Data dialog > Cam-Options > Inner radio-button.

The inner cam will show again.

4.Click OK-tiny-11-15 to close the Cam-Data dialog


When you close the Cam-Data dialog, the 2D-Cam may once again display as  a Groove Cam.

5.Double-click the 2D-Cam to open the 2D-Cam dialog

6.In the 2D-Cam FB > Display tab > Display Cam-Profile as: Inner

7.Close the 2D-Cam dialog.

The Cam-Data FB now has a link to the Inner profile of the 2D-Cam

STEP 4: Add a Measurement to measure from the center of the Cam-Shaft to the Cam-Profile

1.Mechanism-Editor: Click a Kinematic FB > Add Measurement FB

2.Mechanism-Editor: Click the start-Point (center) of the Cam-Shaft

3.Mechanism-Editor: Click the graphic-area

4.Mechanism-Editor: Connect a wire from the Top out-put-Connector of the Measurement FB to the Y1 (top) input-connector of the Graph FB.

STEP 5: Connect wires from the Cam-Data FB to the Graph FB (see image above)

1.Mechanism-Editor: Connect a wire from the Pressure-Angle output-connector(4) of the Cam-Data FB to the Y2 input-connector of the Graph FB.

GST-7-301

STEP 6: Open the Graph-Settings dialog

GST-7-3-Design-Set-7-013

1.Click : Graph toolbar > Graph-Settings

STEP 7: Edit the Minimum and Maximum Scales for each Plot.

1.Graph-Settings > Title and Input Selection  > Y1 : Dis Red-14-2

2.Graph-Settings >  Y-axis   : Disable Auto-scale Red-14-3

3.Graph-Settings >  Y-axis   : Y maximum = 150 ; Y minimum = 0Red-14-4

Set the Maximum and Minimum Pressure-Angle

4.Graph-Settings > Title and Input Selection  > Y2 : Pressure-Angle

5.Graph-Settings >  Y-axis   : Disable Auto-scale

6.Graph-Settings >  Y-axis   : Y maximum = 60 ; Y minimum = -60 (edit again to ±40 as the Pressure Angle improves)

7.Close the Graph-Settings dialog.

Save your model

Graph Settings: Limits of Measurement

Graph Settings: Limits of Measurement

Graph FB with Limits for Measurement

Graph FB with Limits for Measurement


Note:

I would normally set the maximum and minimum Pressure-Angle values to ±35.

However, the Pressure-Angle has a large negative value. Hence, we can set a large range, and reduce the range as the Pressure-Angle improves.