﻿ Step 6D1.1: Prep 1A-D: Slider [Translating-Follower] driven by a Cam

# Step 6D1.1: A Basic Slider driven by a 2D-Cam.

### We add a Slider, and a rotating Cam to move the Slider as a Translating-Follower.

 Preparation 1A: Add a Part, Add a Sketch to the Part, Add a Line to the BasePart

Add a Mechanism to a Plane.

Then, in the Mechanism-Editor:

 STEP 1: Add a Part – see the image to the left.

 STEP 2: Edit the Part.
 STEP 3: Add a sketch to the Part similar to the sketch shown to the left. Make sure it is a sketch-loop.
 STEP 4: Close the Part-Editor

 STEP 5: Edit the Base-Part
 STEP 6: Add a Line to the Base-Part, and a dimension.
 STEP 7: Close the Part-Editor.

Question: Why is the Line in the Base-Part Green, and the Lines in the Added-Part are Blue?

Answer: The colour of the sketch-elements in a Part are equal to the colour of the Part-Outline in the Mechanism-Editor.

The Base-Part is a kinematically-defined Part and, therefore, it is Green.

The Added-Part is not yet kinematically-defined and, therefore, it is Blue.  It is often called a Free-Part.

 Preparation 1B: Add a Slide-Joint

 STEP 1: Click Add Slide-Joint, in the Kinematic-elements toolbar

 STEP 2: Click the Line in the Base-Part
 STEP 3: Click the CAD-Line along the centre of the Added-Part (deep Green colour

In the image to the left, the second Line is being clicked.

The image below shows the Slide-Joint.

The Part-Outline is blue. This means it is not kinematically-defined. You can still drag the Part along the Slide-Joint if you drag the Part-Outline

To remind you: the Slide-Joint is given symbolically in the graphic-area by:

 1 Two rectangles that extend along the length of the two Lines that are each a child to each Part in the Slide-Joint:
 • a thin rectangle (the 'slide-rail') on the kinematically-defined (Green) Part
 • a wider rectangle ('slide-block') on the free (Blue) Part
 2 A small filled arrowhead on the ' start Point of the Line that is the kinematically-defined Part (this is the Base-Part). The arrowhead direction gives the positive direction of the Slide-Joint.

Note: As a reminder: the 'start-Point' of Lines and Parts is the Point where you mouse-button-down to add and 'Drag' the Line or Part. Parts show its origin with the XY-axes. However, Lines do not show their axes. You must remember the start-Point and origin of a Line.

 Preparation 1C: Add a Slider Motion Dimension FB, Motion FB, and Linear Motion FB

 STEP 1: Kinematic-FB toolbar > Add Motion-Dimension FB.

Reminder: You can add a Motion-Dimension FB to a Pin-Joint or a Slide-Joint, to make a Rocker or Slider respectively.

The Command-Manager shows you must select three elements.

 STEP 2: Click the Rectangular Symbol for the Slide-Joint.

You can select the Rectangle that is around the Line in the Sliding-Part, or around the Line in the Base-Part.

Because you select a Slide-Joint as the first element, the second and third elements can only be Points.

 • You must select a Point in the kinematically-defined Part (Green) – also called the 'Solved' Part.
 • You must select a Point in the Part that is not yet kinematically-defined Part (Blue)

 STEP 3: Click the Point with a small arrowhead at the start of the Line in the Base-Part - it is Green
 STEP 4: Click the Point at the start of the Line in the sliding-part - it is Blue.

Top-Tip: Each Line has 2 Points. Try to select the start-Point of each Line as you add the Motion-Dimension FB to the Slide-Joint.

The Added-Part is Green to indicate it is now a kinematically-defined Part.

Edit the Base-Value with the Motion-Dimension dialog-box.

 STEP 5: Double-click the Motion-Dimension arrowhead or the Motion-Dimension FB icon in the graphic-area

Change the Base-Value to 30[mm]

To make the Slider move and be useful, add a Motion FB and a Linear-Motion FB.

 STEP 6: Click the start-Point of the Line in the Part that is still Blue
 STEP 7: Click the Kinematic-FB toolbar > Motion FB and the graphic-area
 STEP 8: Click the Kinematic-FB toolbar > Linear-Motion FB and the graphic-area
 STEP 9: Connect the Function-Blocks.

If you cycle the machine (ALT+C ), the Slider will move from 30mm to 130mm then return, and again and again for each machine cycle.

 Preparation 1D: Add a 2D Cam and Cam Follower

We rotate a 2D-Cam to drive the slider back and forth.

Add the sketch for the centre of a cam-shaft.

 STEP 1: Edit the Base-Part
 STEP 2: Add a short, horizontal Line, approximately where you want the centre of the cam-shaft.

You can see the new Blue Line, at the bottom. It is Blue because we have not yet specified its Length.

Add a sketch for the Cam-Follower.

 STEP 3: Add a circle to represent a Cam-Follower Roller in the Slider.

After you exit the Part-Editor:

 STEP 4: Add a Profile to the Circle to the sketch of the Cam-Follower Roller.

Add a 'cam-shaft' that rotates one time per machine cycle. This is Tutorial 1.

Use the Line in the Base-Part as the centre of the cam-shaft.

 STEP 5: Add a Part
 STEP 6: Add a Pin-Joint
 STEP 7: Add a Motion-Dimension FB, and
 STEP 8: Add a Linear-Motion FB.
 STEP 9: Connect the Function-Blocks

Now, at last, add the 2D-Cam

 STEP 10: Click Add 2D-Cam.
 STEP 11: Click the new cam-shaft
 STEP 12: Click the Cam-Follower Roller
 STEP 13: Click  in the Command-Manager.

The new 2D-Cam shows in the graphic-area.

If you cycle the model, the 2D-Cam rotates one time as the Slider moves back and forth one time.

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