Retain Degrees of Freedom

In some cases, it is appropriate that certain parts move as a rigid body and a joint is not required. As far as the movement of these parts is concerned, the welded body functions like a subassembly moving in a constraint chain within a parent assembly. Similarly, at other times, components making up a welded group need degrees of freedom for movement within the simulation. Such is the case with the welded group in the Saw model.

Create a 2D contact

  1. In the browser, expand Mobile Groups.
  2. Right-click the Follower Roller, and click Retain DOF. The roller retains its motion characteristics.
  3. In the graphics region, click and drag the Follower away from the Cam crank assembly.
  4. On the ribbon, click Dynamic Simulation tab Joint panel Insert Joint and from the list, select 2D Contact.
  5. Select the Cam profile edge (1).
  6. Select circular sketch (2) on the roller component.
  7. Click Apply. As you can see, sketch geometry can be used to help define the simulation.
  8. Drag the Follower until the roller contacts the cam. Notice it does not penetrate. The 2D contact established a mechanical relationship between the two components.
  9. Set the properties for the 2D contact and display the force vector. In the browser, right-click the 2D Contact joint and click Properties.
  10. Set the Restitution values to 0.0.
  11. Expand the dialog box to access the lower section. Check the Normal box and set the Scale to 0.003.