This tutorial is Add Cam with an Oscillating Flat-faced Cam-Follower

Add the Parts for the Cam and the Follower

In MechDesigner, the Parts can be in any Kinematic-Chain.

However, in this tutorial, we keep things simple. We add the parts for the cam and the cam-follower directly to the Base-Part.


STEP 1: Add a Mechanism-Editor
STEP 2: Edit the Base-Part
STEP 3: Add a Line for the Crank 1s-red
STEP 4: Add a Line for the Rocker2s
STEP 5: Add dimensions and constraints to the sketches

In the image, you can see that the Line2s for the Slider does not need to be vertical or horizontal, or on a radial axis from the Crank centre-Point 1s-red.

In this case the Line for the Slider is:

at an angle of 50º
offset from a radial axis by 10mm. [Actually, the important dimensions will locate the cam-follower within the Slider].


STEP 6: Close the Part-Editor
STEP 7: Add a Crank1s-red
STEP 8: Add a Rocker2s

Add the Linear-Motion and Motion FB, and connect the wires.

Step 8 is complete.


STEP 9: Edit a Motion for the Slider - about 30mm stroke.

Add the Flat-faced Cam-Follower

We must make a sketch-loop for the Flat-Faced Cam-Follower. One of the sketch-elements must be a Line.

I have found the best shape for the Cam-Follower is a narrow rectangle. The long side of the rectangle becomes the contact surface.


STEP 1: Add a Line1s-red that will be in contact with the cam
STEP 2: Complete a rectangle with a Line2s that is much shorter than Line1s-red and they are perpendicular [⊥].
STEP 3: Complete the sketch with dimensions and constraints.


Make sure the long-rectangle is a 'sketch-loop'.


STEP 4: Complete the sketch with dimensions and constraints.
STEP 5: Exit the Part-Editor
STEP 6: Add a Profile to the rectangular sketch-loop1s-red

In this case the flat-face is offset to the Pin-Joint.


Step 6 is complete.


Add the 2D-Cam


STEP 1: Add a 2D-Cam


1.Mechanism menu (or Contextual Toolbar) > Add 2D-Cam

The Command-Manager has two selection boxes for two elements:

1.Click a Part - the Crank1s-red
2.Click a Profile - the long, narrow rectangular profile 2s

Finally, to end the Add 2D-Cam command:

3.Click OK in the Command-Manager.

You can see in the image that the cam does not seem to 'complete'.

The problem, in this case, is classic under-cutting.


1.Edit the motion so that the cam remains in contact.

I have edited the rise and return segments so that they are longer and the dwell segments are shorter - see MotionDesigner Help.


Lastly we need to hide the 'external' Cam with the Cam Properties and Display dialog-box.

The external cam is either Cam 1, or Cam 2.

STEP 2: Edit the 2D-Cam

To do this:

1.Move your mouse-pointer over the cam so it highlights.
2.Double-click to open the Cam Properties and Display dialog-box

The 2D-Cam Properties and Display dialog-box opens.


In the 2D-Cam Properties and display dialog:

If necessary, click the Cam Visibilities separator

STEP 3: Click the Cam1 (or Cam2) to hide one of the Cams


In the Cam Properties and Display dialog-box it is also possible to show the 'Pitch-Curve'.

This is nonsense with a Flat-faced Cam Follower.

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