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:
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. |
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| 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
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Add menu > Mechanism sub-menu > Solids sub-menu > Add Polyline |
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The Command-Manager suggests:
Click a '2D-Cam' or 'Gear-Pair'. Use the Polyline as a sketch for a Profile/Extrusion.
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You can click the 2D-Cam in:
- or -
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| STEP 3: | Click OK in the Command-Manager |
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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.
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| 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] |
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| STEP 3: | Click the 2D-Cam in the graphic-area |
In the Command-Manager, you should see the Polyline is in selection-box.
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 Assembly-Tree with 2D-Cam, with Profile/Extrusion element. |
Look in the again.
If you expand Part with the cam, we see a:
| • | Cam-Plate [a child to the Part)] |
| o | 2D-Cam [as a child to the Cam-Plate, with a 'tick' to indicate it is a 'good' cam [in this case]] |
| o | Note: It is your decision as to whether the Cam is 'OK or 'Not OK'. |
| • | Profile [a child to the Part] |
| o | Extrusion [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.
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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.
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| 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. |
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Step 1: Add the Polyline to the 2D Cam