When you want to measure and plot Forces* at a joints contact between Cam and Follower Profile, contact at gear-teeth, ... , you must make sure the “power-source” is the “correct Force element” for each degree-of-freedom in a kinematic-chain.

Force elements are: Pin-Joints, Slide-Joints, 2D-Cams, Springs, and pulleys.

Each degree-of-freedom in a kinematic-chain has one Force element that can also be the Power-Source.

Which is the “correct Force element”?

The correct Force element in the MechDesigner model should be at the same joint or machine-element as your actual machine. For example, if in your machine a Servo-motor drives a camshaft, the correct Force element is the Pin-Joint at the center of the 2D-Cam. If a 2D-Cam drives a kinematic-chain, the correct Force element is the 2D-Cam.

When the power-source is not the correct Force element, the Forces and Torques we calculate will not be those Forces you need to size your bearings, materials, motors, ... .

In the default case, the power-source is a Rotary Motor or Linear Motor at the joint whose motion you control with a Motion-Dimension FB. Frequently, the motor is not at the joint with the Motion-Dimension. For example, a 2D-Cam can be the power-source to move a kinematic-chain of a Follower.

When the power-source for a degree-of-freedom is not the correct element, you must use the Configure Power Source dialog to move it to the correct element.

* Force is the generic term we use for Forces and Torques.

In the default case, the Power-Source is at the joint whose position and motion you control with a Motion-Dimension FB.

A Motor-Symbol represents a Power-Source at the joint.

To see the Motor-Symbol, toggle on:

•Forces toolbar > Force-Vectors: Calculate

•Force toolbar > Force-Vectors: Display

1.Click the Kinematics-Tree in the Element-Explorer

2.Click the “Kinematic-Chain” for which you want to control the Power-Source.

The text “Kinematic-Chain” should be Blue.

3.Right-click “Kinematic-Chain” in the Kinematics-Tree

4.Click Configure Power Source in the shortcut menu (see image, left)

OR

When “Kinematic-Chain” is Blue.

3.Press the ALT+P keyboard shortcut

The Configure Power Source dialog is now open.

See Configure Power Source dialog.

In the Kinematics-Tree:

1.Click the Kinematics-Tree in the Element-Explorer

2.Click the Kinematic-Chain

The  Kinematic-Chain  should be Blue.

3.Click Forces toolbar > Configure Power Source icon.

or

3.Forces menu > Configure Power Source

The Configure Power Source dialog is now open.

See Configure Power Source dialog.