Couplers

Use the Couplers tool to couple the rotational or translational movements of connected parts. You can create two-way or three-way couplers.

Location: Motion ribbon, Connections group


Click the satellite icon that appears when you hover over the Couplers tool to view a list of all joint couplers in your model.

A coupler allows you to specify a mathematical ratio which affects the movement of parts. It's useful for conceptual prototyping and general motion modeling. However, if you're interested in capturing detailed loading (like force distribution on gear teeth) or lash effects, these are better handled by motion contacts.

Valid Joint Types and Connections that Can Be Coupled

This tool works on a variety of connections (joints, supports, and implicit joints in motors, actuators, and springs). Flexible joints cannot be coupled.

Can Be Coupled* Can't Be Coupled
  • Pin
  • Grounded pin
  • Sliding pin
  • Grounded sliding pin
  • Hinge
  • Cylindrical
  • Translational
  • Ball and socket
  • Planar
  • Unknown

*In addition to list above, Inspire Motion also recognizes implicit joints such as the centerline joint of a motor or torsion spring, or a hole support with a translational degree of freedom.

Add/Edit Joint Couplers

Create or edit joint couplers between joints or at free joints.

Coupled joints must be rigid or virtual. Use the menu define the search parameters to only show rigid joints or to force coupled joints to be rigid. You can also exclude design spaces and ground parts from part selection.

  1. Select the Couplers tool.


  2. Select what method to use to create the couplers using the guide bar.


  3. Select joints to add to the coupler.
    Method Workflow
    At Free Joints This method finds part pairs associated with free joints, which are shown in red.
    • Select a red pair to create a coupler.
    • Use the navigation arrows on the guide bar to jump from one part pair to the next. If there are no free joints visible in your model, no part pairs are presented.
    • Alternatively, click Create All on the guide bar to create couplers between all detected (red) pairs.
    Note: If nothing appears in red, you either have no free joints, or they are already used in another coupler. Try using the By Joints option on the guide bar instead.
    By Joints: Two-Way Couplers This method detects joints that can be coupled. Entities that cannot be coupled are shown transparent.
    • Select two joints to create a coupler.
    • Use the Ctrl key to add a third joint to the coupler.
    • When creating couplers, use the guide bar to show only rotational or translational joints.
    By Joints: Three-Way Couplers This method detects joints that can be coupled. Entities that cannot be coupled are shown transparent.
    • Hold the Ctrl key and select three joints to create a coupler.
    • Alternatively, use the Ctrl key to add a third joint to an existing two-way coupler.
    • When creating couplers, use the guide bar to show only rotational or translational joints.
  4. In the microdialog, edit the Scale values to specify the coupler ratio.
  5. Click the +/- icon to reverse the coupler's direction if needed.
  6. Right-click and mouse through the check mark to exit, or double-right-click.
Tip:
  • When using the guidebar navigation arrows during coupler creation, hold Ctrl when you click the Create button to create the coupler and automatically advance to the next candidate pair.
  • An option to hide all couplers is available in the right-click context menu. In some models hiding all couplers may improve performance of the animation.
  • If the movement of the motion analysis is opposite what you expected, change its direction. This can be done using the Reverse Direction option on the microdialog or Couplers table.
  • Use the Flip Scale icon on the microdialog to swap the scale values for the coupler ratio.
  • Use the Flip Entity Order property to change the order of the Entities list in the Property Editor. This also influences the appearance of curves in coupler plots.
  • You may get an error message that the coupler requires a joint or support to be rigid. To avoid this error, click on the guide bar, and then select Force coupled joints to be rigid before creating the coupler, or change the joint to be virtual.
  • Suppress/Unsuppress a coupler to understand its effect on your model. On the coupler, right-click and select Suppress. From the Model Browser or Table, right-click and select Unsuppress.

Additional Search Parameters

Click the menu on the guide bar to apply global options before creating joint couplers.

Only show rigid joints
Enabling this option prevents flexible joints from being shown as candidates for selection when using the By Joints method.
Only show grounded joints
Enable this option so the candidates for selection will only display joints that are connected to ground when using the By Joints method.
Exclude design spaces
Design spaces are excluded from the find operation by default.
Exclude ground parts/connections
Enable this option to exclude ground parts and any connections to ground from the find operation.
Force coupled joints to be rigid
Enabling this option redefines flexible joints as rigid if they are included in a coupler.

Microdialog Options

Use the options in the microdialog to edit the coupler.



Figure 1. Couplers Microdialog
Scale
Enter scale parameters to define the coupler ratio.
Reverse Direction
Click the icon to reverse the direction of the coupler. You can also click the arrow on the coupler to change its direction.
Set Joint Coupling
Define whether the scale applies to translation or rotation.
Reset Default Scales
Click the icon to restore the default values.
Flip Scale 1 and Scale 2
Click the icon to swap the scale values.

Couplers Table

The Couplers table lists all of the joint couplers in your model including the entities in the coupler, whether the coupler is rotational or translational, and the scale factors.

Location: Couplers tool, satellite icon

Figure 2. Couplers Table
To Do this
Rename a coupler Select the cell in the table and then click again to make the field editable.
Edit a parameter Select the cell in the table and then click again to make the field editable.
Sort a column Click the column header. Click repeatedly to toggle between ascending and descending order.
Add or remove columns Right-click on a column header.
Note: If a coupler includes a third joint, right-click on a column header to add additional columns for Joint 3 Coupling, Scale 3, and Reverse Third Direction.