The Objective of this Step is to:

Show you how to add a Polyline, and Profile to a 2D-Cam.

Summary of this Step:

Use these commands.

1.Move the model to 0º with the Home key on your keyboard
2.Add Polyline to the 2D-Cam
3.Add Profile to the Polyline
4.Add sketch-loops and Profiles

You need this step only if you want to:

Model the Cam as a Solid.

For example, if you want to check the model for collisions.

Know the Mass Properties: Mass, Centre-of-Mass, and Moment-of-Inertia of the Cam.

For example, if you want to balance the Cam.

Include the Mass Properties in a Force Analysis.

tog_minus        Step 1: Add the Polyline to the 2D Cam


STEP 1: Click 'Home' on your keyboard to send the Master-Machine-Angle to Zero.

Why Home? The Polyline will be out-of-phase with the 2D-Cam if you do not 'Home' the model before you Add Polyline.

STEP 2: Click Add Polyline: In the Extrusion Toolbar
- or -
Add menu > Mechanism sub-menu > Solids sub-menu > Add Polyline


The Command-Manager suggests:

Click a '2D-Cam' or 'Gear-Pair'. Use the Polyline as a sketch for a Profile/Extrusion.

STEP 2: Click the 2D-Cam


You can click the 2D-Cam1s-red in:

the graphic-area

- or -

the Assembly-Tree


STEP 3: Click OK in the Command-Manager

If you edit the model, the shape of the 2D-Cam changes.

When you edit an element in the model, it is possible that the shape of the 2D-Cam changes. However, MechDesigner does NOT update the Polyline.

You must update the shape of the Polyline to become the same as the shape of the 2D-Cam.

To update the Polyline:

1.Click the Home key to put the MMA at 0.
2.Click Add Polyline again.
3.Click the 2D-Cam that you want to update.
4.Click OK in the Command-Manager.

MechDesigner updates the existing Polyline. It does not add a new Polyline.

tog_minus        Step 2: Add a Profile to the Polyline


STEP 1: Click the Home Key to put the MMA at 0
STEP 2: Click Add menu > Mechanism sub-menu > Solids sub-menu > Add Profile [or see Solids toolbar]




STEP 3: Click the 2D-Cam in the graphic-area

In the Command-Manager, you should see the Polyline is in selection-box.

STEP 4: Click OK
Assembly-Tree with 2D-Cam, with Profile/Extrusion element.

Assembly-Tree with 2D-Cam, with Profile/Extrusion element.

Look in the Assembly-Tree again.

If you expand Part with the cam, we see a:

Cam-Plate [a child to the Part)]
o2D-Cam [as a child to the Cam-Plate, with a 'tick' to indicate it is a 'good' cam [in this case]]
oNote: It is your decision as to whether the Cam is 'OK or 'Not OK'.
Profile [a child to the Part]
oExtrusion [a child to the Profile]

MechDesigner does not list the Polyline in the Assembly-Tree. If you click the cam in the graphic-area, you will see the Polyline elements in the Selection-Window.

tog_minus        Step 3: Add Profiles to the other Parts

It is better to use the Part-Editor to add sketch-loops. Do not merge the centre of circles and arcs with Points that you also use for Pin-Joints.

Add Profiles to Parts in a kinematic-chain with the Add Auto-Profiles tool.


STEP 1: Click Auto-Profiles in the Extrusions Toolbar
STEP 2: Click OK in the Command-Manager


Use the Add Layers tool to move the Extrusions by different amounts along the Z-axis of their Parts

STEP 3: Click Auto-Layer in the Extrusions Toolbar

View the mechanism in the Model-Editor.

STEP 4: Click the Model name-tab at the top of the graphic-area.

Tutorial and Reference Help Files for MechDesigner and MotionDesigner 13.2 + © Machine, Mechanism, Motion and Cam Design Software by PSMotion Ltd