Add a sketch-loop to represent the path of the belt.

STEP 1: Edit the Base-Part

STEP 2: Add a sketch-loop to represent the path of the Belt

In this example, the sketch-loop has two Arcs and two Lines.

STEP 3: Add a Line and merge the start-Point with center-point of the Arc.

STEP 4: You MUST dimension each Arc

The radius of the Arc is not important. MechDesigner will add a Pulley with an integer number-of-teeth and pitch to give a radius that is near to the dimension. You can edit the number-of-teeth and tooth pitch later, of course.

STEP 5: Close the Part-Editor

STEP 6: Add a Motion-Path FB

Click the sketch-loop that represents the path of the belt.

The Motion-Point shows at the start-Point of the sketch-element you select in the sketch-loop.

STEP 7: Add one Part for each Arc of the belt.

The length of each Parts is not important.

STEP 8: Add a Pin-Joint between a Point in each Part and the center-Point of an Arc.

Usually, use the origin of each Part for the Pin-Joint.

STEP 9: Add a Motion-Dimension FB to the Part you wish to be the Driving Pulley.

This is only one way to add a Green rotating-Part as a Driving Pulley. In this case, it is a Rocker.

You must do Add Pulley for each Pulley.

Do

•Add menu > Mechanism sub-menu > Add Pulley

- or -

•Kinematic-elements toolbar > Add Pulley

Add Pulley opens in the Command-Manager.

Click, in the graphic-area, the four elements from top to bottom.

The Pin-Joint

The Motion-Path FB

The Part-Editor opens to show the sketch-loop to which you added the Motion-Path FB.

The Dimension of the Arc sketch-element with the Green rotating-Part

The Part-Editor closes.

The Part joined with a Pin-Joint at the center of the Arc.

Click to complete the command.

MechDesigner adds a Driving-Pulley.

Do Add Pulley again, to add a Pulley to the right-hand Arc and Part.

Notes:

A Driving-Pulley is driven by the kinematically-driven Part (the Rocker, in this case).

•Default color of a Drive Pulleys is Cyan

•Belt Speed = Radius of Drive-Pulley * Angular-Velocity of the Drive-Pulley

A Driven-Pulley is added to the free-Part

•Edit each Pulley : Number-of-Teeth in the Edit Pulley dialog.