STEP 1: Edit the Base-Part

STEP 2: Add a closed sketch-chain (sketch-loop) to represent the Path of the Belt

We will add a Line, and then we can add a Rocker in the Mechanism-Editor.

STEP 3: Add a Line - its start-Point is merged or coincident with the center-point of an Arc.

STEP 4: You MUST add a dimension to each Arc

The exact radius of the Arc is not important.

STEP 5: Close the Part-Editor

STEP 6: Add Motion-Path FB  

Select 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 a Part for each Pulley.

Add one Part near to the center-Point of each Arc

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

There is one rotating Part (that is, a Part + Pin-Joint) for each Pulley.

The length of each Part is not important.

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

A maximum of one kinematically-defined Part can be a Driving Pulley.

You must do Add Pulley for each Pulley

Add menu > Mechanism sub-menu > Add Pulley

- or -

Kinematic-elements toolbar > Add Pulley

The Add Pulley dialog starts in the Command-Manager.

Do Add Pulley to the kinematically-defined Part first.

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

1.The Pin-Joint

2.The Motion-Path FB

The Part-Editor opens with sketch-path to which you add the Motion-Path FB

3.The radius Dimension of the Arc

The Part-Editor closes

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

MechDesigner adds the Pulley.

Do Add Pulley again four more times to add a total of five Pulleys.

Notes:

Default colors of the Pulleys:

Driving Pulleys are Cyan

Driven Pulley are Magenta

•The radius of each Arc changes to give an integer Number-of-Teeth.

•Edit the Number-of-Teeth with the Edit Pulley dialog.

Edit the Number-of-Teeth on a Pulley.

1.Open the Pulley dialog-box

Double-click a Pulley in the graphic-area

- or -

See How to open a dialog-box

In the Pulley dialog-box

2.Edit the Number-of-Teeth

Repeat 1 and 2 for each Pulley.

3.Edit the Motion-Dimension FB to 0º .

When the Driving-Pulley is at 0º, the other Pulleys will also be at 0º.

Belts have an integer number-of-teeth. Also, belt manufacturers have preferred lengths of belts. We use the Motion-Path dialog-box to enter a Target Path Length

The Target Belt Length tool moves a pulley, or another controlling-dimension, to edit the length of the belt.

Thus, we need a dimension in the sketch-path that will change the length of the belt. We will edit the length of the Belt to an length that is exactly divisible by Tooth-Pitch to give an integer number of teeth on the Belt.

In the design to the left, we will make the Tensioning Pulley the pulley at the top the sketch-path.

Therefore, we will use the dimension highlighted in RED. (164.89)

This dimension is the Controlling Dimension.

MechDesigner adjusts this dimension as we edit the Target Path Length

STEP 1: Edit the Motion Path FB to edit the Length of the Belt.

1.Double-click the Motion-Path FB  to open its dialog-box dialog box (or see How to open a dialog-box)

2.Motion-Path dialog-box > Length Control tab > Belt-Tooth Pitch  > Belt Tooth Pitch =5 (mm)

3.Motion-Path dialog-box > Length Control tab > Path Length using Dimension 

You will see the Actual Path Length = 1228.9mm  It is Read-Only.

4.Click the Controlling Dimension box

The Part-Editor opens to edit the Part in which the belt is defined by the sketch-path.

5.Click the dimension you want to use to change the length Belt - see image above

The Part-Editor closes

The dimension value shows in the Controlling Dimension box

The default Target Path Length = Actual Path Length

The Maximum and Minimum Dimension Values are Soft-Limits to the Controlling-Dimension.

You can edit the Maximum and Minimum Values if you need to edit the Controlling Dimension by more.

8.Edit the Target Path Length SLOWLY with the Spin-Box tool to increase or decrease the Actual Belt Length.

If needed, you can select a different dimension to adjust.

1.Click the Clear Controlling Dimension button, immediately below Path Length using Dimension