Simulation in SolidWorks

Lever

1. Make a new part on the Front plane.
2. Sketch a 3 inch slot-shaped lever with a 1/8 inch radius with 1/8 inch holes in the middle and at the ends.
3. Extrude to a depth of 1/8 inch.
4. Save the part as Lever.SLDPRT.

Backing Plate

5. Make a new part on the Front plane.
6. Sketch a 6 inch by 6 inch rectangle.
7. Inside the rectangle, draw a horizontal construction line and dimension it to 1.4 inches.
8. Extending upward from the right endpoint, draw a vertical construction line and dimension it to 1.8 inches.
9. Draw 1/8 inch diameter circles at the left endpoint of the horizontal line and the top endpoint of the vertical line.
10. Extrude to a depth of 1/8 inch.
11. Save the part as BackingPlate.SLDPRT.

Lever Assembly

12. Make a new assembly.
13. Insert the backing plate.
14. Insert two levers and mate their center holes to the holes in the backing plate, using Coincident mates.
15. Each lever should rotate freely.
16. Verify that moving one level has no effect on the other; it passes right through it.
17. Rotate the left lever so that it is vertical, and the right lever to a 45 degree angle (running up and to the right).
18. Save the assembly as Motion.SLDASM.

19. Go to the SOLIDWORKS Add-Ins tab.
20. Turn on SOLIDWORKS Motion.
21. Go to the Motion Study 1 tab (see the bottom of the window).
22. Add a motor to the simulation, using the inner face of the left lever's center hole. Set the rotation speed to 4 rpm.
23. Add a Solid Body Contact between the two levers.
24. Change the mode from Animation to Motion Analysis.
25. Click on the Calculate button and observe the motion.
26. Click on the Play button and observe the motion.

27. Add a damper to the simulation.
28. Set the damper type to Torsional Damper.
29. Set the Damper Parameter to the second lever.
30. Set the Damping Constant to 0.00001 lbf-in/(deg/s).
31. Press the Calculate button and observe the motion.

32. Switch back to the Model tab (bottom of window).
33. Make a new part on the Front plane.
34. Sketch a circle centered on the origin with a 1/8 inch diameter.
35. Sketch a second circle centered on the origina with a diameter of 0.35 inches.
36. Extrude to a depth of 1/4 inch.
37. In the feature manager tree, right click on Material and select Brass.
38. Save the part as Weight.SLDPRT.
39. Switch back to the assembly by pressing Control-Tab.
40. Insert the weight into the assembly and mate it to the bottom hole in the right lever.
41. The right lever should still be at a 45 degree angle.
42. Switch back to the Motion Study 1 tab.
43. Press the Calculate button and observe the motion. The weight doesn't have much effect.

Gravity

44. Add gravity to the simulation.
45. Set gravity to align with the Y axis.
46. Press the Calculate button and observe the motion.
47. Press the Play button to see a real-time playback.

48. Increase the simulation duration to 12 seconds by dragging right the keypoints (diamond shapes) for the simulation and the motor.
49. Press the Calculate button and observe the motion.

Changing the Starting Configuration

50. Grab the time index and slide it all the way to the left.
51. Now you can change the initial configuration by clicking and dragging parts in the graphics window.
52. Press the Calculate button to calculate a new motion sequence.

Complex Bodies

53. Start a new part on the Front plane.
54. Sketch a blob shape using the spline tool.
55. Put a 1/8 inch diameter hole in the center of the blob.
56. Extrude to a depth of 1/8 inch.
57. Save the part as Blob.SLDPRT.
58. Go back to the assembly.
59. Suppress the leftmost lever.
60. Insert the blob and mate it to the left hole in the backing plate.
61. Add a solid body contact between the blob and the right lever.
62. Add a motor to rotate the blob.
63. Press the Calculate button and observe the motion.

Dave Touretzky