2D-Cam: The Elements, Function-Blocks and Dialog-Boxes

2D-Cams have a number of 'related' elements, FBs, and Dialog-Boxes. Their relationships are indicated in the table below.

You must link a 2D-Cam to a Cam-Data FB to get the 2D-Cam's kinematic-data : cam-coordinates, pressure angle, radius of curvature.

To find a 2D-Cam's force, stress and cam-torque data, you must also make sure to 'Configure the Power Source' correctly, enter its material properties, and edit the mass properties of each Part in the model. Then you can also use the Cam-Data FB to get Contact-Force and Minimum Contact Shear-Stress.

How to open the Cam Display and Properties dialog-box

To open the 2D-Cam dialog box

1.Click a 2D-Cam in the graphic-area

In the Selection-Window

2.Right-click the 2D-Cam
3.Click Edit element in the contextual-menu

- or -

See How to open a Dialog-Box


STEP 1A

Add 2D-Cam

Select a:

Part: the Cam-Part
Profile: the Cam-Follower

... optional ...

 

STEP 1B

Open: Cam Display and Properties dialog-box

Display Cam1, Pitch-Circle, Cam2
Display Cam as Profile, Pressure Angle, Contact-Force*, ...
Display Colour

Note: Make sure *material-properties are correct.

STEP 2A                

Add Cam-Data FB

STEP 2B

Edit Cam-Data FB to open Cam-Coordinates dialog-box

Select the 2D-Cam

Do STEP 3B immediately, or

Do Step 3A, then do STEP 2B and STEP 3B again.


STEP 3A

Cam-Analysis [with Graph FB]

Output-Connectors of Cam-Data FB:

Contact-Force*
Contact-Shear-Stress*
Radius-of-Curvature
Pressure-Angle

STEP 3B

Calculate Cam-Coordinates as Points or Arcs

Save as DXF, TXT, STEP
Transfer cams directly to SOLIDWORKS
Save As Points, Arcs

*Force analysis only: Configure Power Source, Mass Properties of Parts, Cam and Cam-Follower Material Properties.

Cam Display and Properties dialog-box

Dialog-R13.2-CamDisplay

Cam Display

tog_minus        Cam Visibilities 

Dialog-R13.2-CamDisplay-CamVisibilities

Display:

Cam 1
Pitch-Curve. [a dashed line]

and , or

Cam 2

Notes:

You must display a minimum of one.
Look in the graphic-area to see which is which cam.

tog_minus        Cam Display Options 

Dialog-2DCam-Display-CamDisplayOptions

Display Cam Contour as:

Cam-Profile [default]
Maximum Contact Shear-Stress**
Contact Force*
Pressure Angle

See also: Cam-Data FB


*&** The Power Source must be configured correctly.

1.Configure the Power Source:  to make the 2D-Cam as the Power Source for the kinematic-chain in which the Cam-Follower is a Part.
2.The Elastic Modulus and Poisson's Ratio must both be correct for the Cam and the Cam-Follower. See Material Properties

Line Thickness of Cam: [default =1]

Increase the thickness of the cam profile.

Increase the Line Thickness for Cam Display that is not 'Cam Profile'.


Show Instant Centres : For the kinemagicians


Cam Profile Colour : If you have more than one cam in the model, then it is helpful to have a different colour for each Cam.

Example Cam Display Option:

Cams in Graphic Area as 'Cams Only'

 

Cam Profile

 

1s-red Cam 1 and 2 are continuous lines.

2s Pitch-Curve is a dashed line.

Cams in Graphic Area as 'Maximum Contact Shear Stress'

Maximum Shear-Stress

Each point around the cam has a unique Maximum Shear-Stress.

See image:

1s-red The value of the Maximum Shear Stress at the contact point

2s The colour of the cam profile agrees with the colour-bar3s.

3s The colour-bar is a scale of the Maximum Shear-Stress.

Cams in Graphic Area as 'Cams Contact Force'

Contact Force

Refer to the image:

1s-red The value of the Contact Force is at the contact point.

2s  The colour of the cam profile agrees with the colour-bar3s

3s The colour-bar is a scale of the Contact Force

Cams in Graphic Area as 'Cams Pressure Angle

Pressure Angle

1s-red The value of the Pressure Angle is adjacent to the contact point between the Cam-Follower and Cam

2s The colour of the Cam agrees with the colour-bar3s

3s A colour-bar is a scale of the Pressure Angle

See Also Pressure Angle

Cam Parameters

tog_minus        Material-Properties 

Dialog-R13.2-CamDisplay-MaterialProps

To calculate the Maximum Contact Shear-Stress enter:

Cam and Cam-Follower's Poisson's Ratio
Cam and Cam-Follower's Elastic Modulus

You must enter all of the zeroes!


Elastic Modulus is also its Young's Modulus.


Notes:

See also: www.matweb.com [internet link] for material properties.

tog_minus        Cam Range and Radius...

Dialog-R13.2-CamDisplay-CamRangeRadius

Check-box: Open Cam / Closed Cam

'Continuous Profile'

- or -

'Open Profile

See below for more details


Radius of Curvature Warning [%]

'Warning' if Roc Warning ≤ (Radius of Cam-Curvature / Radius of Cam-Follower ) × 100%.

The 2D Cam profile in the graphic-area becomes RED if  the Radius of the Cam Curvature becomes small as compared to the Cam Follower Radius.

There is a danger of the Cam-Undercutting

See Also Application Settings


Cam Range Start & Cam Range:

Calculate the cam over a reduced range, Usually less than 360.

For example:

If the cam rotates two times in one machine cycle, then enter Cam Range Start: 0 ; Cam Range : 180
If the cam is a 'slot-cam', the cam-follower moves along the cam in two directions. Then, enter a value in the Cam-Range box to calculate the cam only as the cam-follower moves in one direction.

This is not always possible, as the cam-follower may have a complex motion in the right and left directions, even at points that are not at the two ends of the cam.


CamRange-OpenCam

Examples of Open / Closed Cam and Cam Range

For example: a reciprocating 'Slot-Cam' that moves to the right and left. [see image]

Cam-Range Start: 0 ; Cam Range: 120

The first points of the Cam are at the start [left-side] of the profile.
The cam-follower starts to move from the right-side towards the left again at 120 MMA

CamRange-ClosedCam

Rise Only: clear check-box;

The cam does not have a 'fly-back' line.

Rise-Return: select check box;

The cam does have a 'fly-back' line.

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