Setting Limits on Mates

SolidWorks provides the ability to set limits on mates so instead of being fixed, they have a finite range of motion available. COSMOSMotion supports these mate limits. Learn more.

During the simulation, COSMOSMotion checks the mate limits and applies a reactionary force when the limits are encountered. If whatever is driving the model tries to push beyond the mate limit, COSMOSMotion detects it and stops the simulation.

• The mate limits have been set up in SolidWorks and have the following ranges:

• The outer track is 1300 mm and the slider is 300 mm, so a mate limit of 0-1000 represents the range of allowable travel.
  
  

• The slot in the slider is 280 mm and the moving part is 80 mm long, so a mate limit is 0-200 mm represents the range of allowable travel.
  
  

In this exercise we use a sliding block model to demonstrate the mate limit support in COSMOSMotion.

Loading the Model

To load the model:

1. From the COSMOSMotion installation directory, go to Tutorials/joint_limit_exercise.

2. Make a copy of this folder to a different location and then open joint_limit_exercise_start.SLDASM.
   
   COSMOSMotion informs you which documents will be converted when saved.

The COSMOSMotion mechanism is already mapped from SolidWorks. If you select the Motion tab , you will see the constraints mapped as shown next.

Adding Motion

To see how the limits behave, you will add a motion on the moving part with respect to ground.

To add motion:

1. In the treeview, right-click moving part-1, point to Add Motion, and then select Motion on Part.
   
   When the dialog box appears, select the ground button for the reference part.

2. To define the orientation of the motion, select the features shown next.
   
   

3. From the same dialog box, select the Motion tab.

4. Set Motion On to Translate Z.

5. Set Motion Type to Velocity.

6. Set Velocity to 300 mm/sec.
   
   

Running Simulations

To run the simulation:

1. In the treeview, right-click Motion Model, and then select Simulation Parameters.

2. Set Duration to 3 seconds.

3. Set Number of Frames to 120.
   
   Note that gravity has been turned off in the mechanism.

4. At the bottom of the Browser, select the Run Simulation button .
   
   The moving part slides, hits the limit of the slider slot, and then both parts slide until they hit the limit in the track. This occurs at 2.625 seconds.
   
   Currently no error message is displayed to indicate that the mate limits were exceeded.