This Demonstration simulates the working of an open or closed belt drive with two circular pulleys.
An important parameter in the design of belt drives is the angle of wrap around the pulleys. This is marked by the green lines. For an open belt drive, we have: and for a closed belt drive: . The parameters and are the radii of the driving and driven pulley and is the difference in values between the centers.
You can drag the pulleys by the locators at their centers.