Tutorial: Getting Started with Motion

Learn how to create connections, add a motor and spring damper force, and run a motion analysis.

In this lesson you will learn how to:
  • Ground a part
  • Create a rigid group
  • Connect parts with joints
  • Determine the direction of gravity
  • Add a motor to the model
  • Apply a spring-damper force
  • Run a motion analysis

Open the CAD model

  1. Press F7 to open the Demo Browser.
  2. Double-click the M01_FourBar.x_t file in the Motion folder to load it in the modeling window.


  3. If not already visible, press F2 to open the Model Browser.
  4. Check that the display units are set to MKS.

Ground a Part

  1. Select the Motion ribbon.
  2. Select the Ground tool from the Connections category.


  3. Select the Base part to ground it.
    The part turns red, and the part icon in the Model Browser changes to indicate that it is a ground part.


  4. Right-click and mouse through the check mark to exit, or double-right-click.

Create a Rigid Group

  1. Select the Rigid Groups tool.


  2. Select the Base, Mount Crank, and Mount Clevis parts in the bottom half of the mechanism.
    The parts turn red as you select them.


  3. Click the floating Create New Group icon to place the parts you selected into a new rigid group.


  4. Right-click and mouse through the check mark to exit, or double-right-click.

Run a Simple Motion Analysis

  1. Click the Quick Run button on the Analyze Motion tool to see the model in motion.


  2. Notice that the ground parts remain stationary and some of the unconnected parts fall down due to the effect of gravity.
    Note: The Quick Run is a toggle button, so you can also use it to stop an analysis that is still running.
  3. After the analysis has stopped running, the icon appears and you are automatically placed into review mode. Click the Review Motion Results icon or double-right-click to exit review mode.


Connect Parts with Joints

  1. Select the Joints tool.


  2. Check that the guide bar is set to the default settings (All, Auto) and click the button.


    Joints are created at neighboring parts in the model. The colors indicate the joint state (in this case all have been set to Active).


  3. Right-click and mouse through the check mark to exit, or double-right-click.

Inspect the Gravity Direction

  1. Select the Gravity tool.


  2. Notice that a vector is displayed which indicates the direction of gravity.


  3. Right-click and mouse through the check mark to exit, or double-right-click.

Change the Run Settings and Rerun the Analysis

  1. Hover over the Analyze Motion tool, then click the Run Settings icon to open the Run Motion Analysis window.


  2. Change the Output Rate to 100 by entering the value in the field or clicking the 100 button.


  3. Click Gravity and verify that it is set to Yes.
    This is the default setting for a motion analysis.


  4. Close the Run Motion Analysis window.
  5. Click the Quick Run button on the Analyze Motion tool to see movement of the model with the joint connections in place.


  6. Click the Quick Run button again to stop the analysis.


  7. Double-right-click to exit review mode.

Add a Motor to Drive the Mechanism

  1. Select the Motors tool.


  2. Click the Cen (center) snap point of the Link Crank part to define the shaft connection point.
    The feature turns red.


  3. Select the Mount Crank as the base connection.
    The motor is created, and a microdialog appears with the Speed set to 60 rpm.


  4. Right-click and mouse through the check mark to exit, or double-right-click.

Add a Spring-Damper Force

  1. Select the Coil Spring tool on the Springs icon.


  2. Click the Mid (middle) snap point of the Link Dual Slot part.
    The selected feature turns red.


  3. Select the Base part.
    A coil spring appears and the microdialog shows the default settings.


  4. Click and drag the end point manipulator at the bottom of the spring to relocate it to the Mid snap point of the Base part.


  5. In the microdialog, change the K stiffness value to 2500 N/m.


  6. Click and drag the white arrow manipulator to reduce the spring Diameter slightly.


  7. Right-click and mouse through the check mark to exit, or double-right-click.

Change the Run Settings and Rerun the Analysis

  1. Click the Run Settings icon.


  2. Change the End Time to 2 s by entering the value in the field or clicking the 2 button.


  3. Close the window.
  4. Click the Quick Run button to see movement of the model with motor and coil spring in place.


  5. After two seconds, the run will complete and you will automatically be placed into the Review Motion Results tool.
  6. Optional: Click the Play button on the animation toolbar to review the results.

Review the Motion Analysis Results

  1. Change the Time on the animation toolbar to 0.73 s by dragging the slider bar.


  2. Select Coil Spring 1 in the modeling window to see a plot of the spring forces.


  3. Select Motor 1 to see a plot of the motor's output.


  4. Click on the pin connecting the Link Single Slot to the Link Dual Slot to view a plot for the pin.


    Note: Right-click on the plot to view other components that can be plotted.
  5. Right-click and mouse through the check mark to exit, or double-right-click.