MechDesigner Reference & User Interface > 2.2 Mechanism-Editor > Mechanisms > Machine elements

2D-Cam

Add 2D-Cam and Degrees of Freedom

Add 2D-Cam does NOT remove a degree-of-freedom.

Cam Terminology:

Terms :	Definitions
Cam (or Cam-Part) :	The Part that supports the Cam-Profile shape. Its motion is the input to the Cam system.
Cam-Shaft :	The most common Cam-Part. It is a rotating-Part (a shaft), to which you add the 2D-Cam (or 3D-Cam) as a Cam-Profile. A Cam-Shaft usually rotates with a constant angular-velocity.
Cam-Profile :	The curved surface of a 2D-Cam (or 3D-Cam) that imparts a motion to a Follower by point or line contact with the surface of a Follower-Profile.
Track-Cam or Groove-Cam :	A groove is cut into a Cam-Blank there is an Outer and an Inner Cam-Profile. A Follower-Roller fits in the groove.
Follower or Follower-Part :	The Part that supports the Follower-Profile. Its motion is the output from the cam system.
Follower-Profile :	The surface of a machine component (that is rigidly connected to the Follower-Part. The surface that is in continuous contact with the Cam-Profile.
Follower-Roller :	A Follower-Profile that is cylindrical or barrel-shaped that is rigidly connected to the Follower-Part.
Flat-faced Follower :	A Follower-Profile that is a flat surface that is rigidly connected to the Follower-Part.
Translating Follower :	A Follower-Part that moves along a straight axis.
Reciprocating :	A sliding-Part that has a motion that is non-progressive.
Rotating Follower :	A Follower-Part that rotates about a fixed axis with a progressive or non-progressive motion.
Oscillating :	A rotating-Part that has a motion that is non-progressive.
Progressive Motion :	A motion that moves the Follower-Part generally in one direction.
Non-Progressive Motion :	A motion that returns the Follower-Part to its original position after each machine cycle.
Indexing :	A progressive, usually rotating, motion.
Indexer :	A device whose input is a nominally constant-speed Cam-Shaft and output is a rotating shaft with a progressive motion. After the cam-shaft rotates fully a number of times, the output shaft rotates by 360º.
Cam-Blank :	The material that you need before you cut the shape of the Cam-Profile.

2D-Cam: Typical Work-flow

1.Add a 2D-Cam - see Machine elements toolbar > Add 2D-Cam

If the new 2D-Cam is one from a pair of Conjugate-Cams, or it is one flank of a Groove-Cam

1.a. Add a Conjugate-Cam FB - see Machine elements toolbar > Add Conjugate Cam FB

1.b. Edit the Conjugate-Cam FB to select least two 2D-Cams - see Conjugate-Cam dialog.

2.Select a 2D-Cam or a Conjugate-Cam FB as the Power Source for the Follower - see Configure-Power Source

3.Review the 2D-Cam : Display, Properties, Roller-Life, Cam-Life, ... - see 2D-Cam dialog

4.Add a Cam-Data FB - see Kinematic FBs toolbar > Add Cam-Data FB

5.Edit the Cam-Data FB to link it to the 2D-Cam- - see Cam-Data dialog : Cam Analysis

6.Connect wires from the Cam-Data FB to a Graph FB to analyze 5 parameters - see Cam-Data dialog : Cam Analysis

7.Edit the Cam-Data FB again to calculate the Cam's Coordinates - see Cam-Data dialog : Cam-Coordinates

Prepare to add 2D-Cam (typical):

Preparation for Add 2D-Cam

The elements you need in the model before you do Add 2D-Cam:

Cam - any Part that is kinematically-defined

Follower - any other Part that is also kinematically-defined

Follower-Profile - a Profile in the Follower-Part

The Cam usually moves, but it may be stationary.

The Follower usually moves, but it may be stationary.

The Cam and the Follower must move relative to each other.

The Cam-Part and Follower are usually in different kinematic-chains, but this is not necessary.

Do Add 2D-Cam:

STEP 1: Click Add 2D-Cam

1.Mechanism menu > Add 2D-Cam

1.Machine-elements toolbar > Add 2D-Cam

The command-manager indicates you need to select two elements.

STEP 2: Select the two elements

Element 1 is the Part to which you want to add the 2D-Cam.

1.Click the Part-Outline in the graphics-area, or the Part element in the Assembly-Tree

Element 2 is the Follower-Profile in the Follower.

2.Click the Profile in the graphics-area or the Profile element in the Assembly-Tree

Typically, the Follower-Profile is a Flat-Faced Follower or a Follower-Roller.

STEP 3: Complete the Command

3.Command-Manager: Click in the Command-Manager.

Result :

Graphics-area

The Inner and Outer 2D-Cams show in the graphics-area.

Result :

Assembly-Tree

A Cam-Plate as a child to the Part to which you add 2D-Cam Red-14-3 .

The 2D-Cam is a child to the Cam-Plate.

The icon for the 2D-Cam element in the Assembly-Tree may warn you that it is a “Bad Cam”.

We base the warning of the “Bad Cam” on the 2D-Cam's minimum Radius-of-Curvature as a percentage of the radius of the Follower-Roller.

The warning limit is controlled in two places:

Default Warning: Control the percentage in Application Settings - see here

Warning of each 2D-Cam: Control the percentage in 2D-Cam dialog > Cam Range and Radius

YOU must make sure the cam is suitable for your needs, even if it is a “Good Cam”.

“Good Cam”

“Bad Cam”

Next Steps:

If Force analysis is important

Configure the Power-Source and select the 2D-Cam as the power source.- see Configure Power-Source

Add Mass-Properties to the important Parts in the model - see CAD-Line dialog

Add a Force Data FB to plot Torques and/or Forces over a machine-cycle - see Force-Data FB, Add Spring FB

If the Cam-Part is a Cam-Shaft, then you can also select a servomotor and gearbox - see Servomotor and Gearbox

Edit the 2D-Cam

Select and edit the 2D-Cam to open the 2D-Cam dialog.

You can display its Pitch-Curve, edit its color, the thickness of the cam-profile, ...

You can estimate the Roller-Life and Cam-Life.

Analyze the Cam over a Machine-Cycle

Add and edit a Cam-Data FB and link it to the 2D-Cam you want to analyze - see Add Cam-Data FB and Cam-Data FB dialog : Cam Analysis

Analysis parameters include: Maximum Shear-Stress, Contact-Force, Radius-of-Curvature, Pressure-Angle, Sliding-Velocity

Calculate and export the Cam-Coordinates in different formats

Add and edit a Cam-Data FB to link it to the 2D-Cam for which you want the Cam-Coordinates - - see Add Cam-Data FB and Cam-Data FB dialog Cam-Coordinates

Calculate the Cam Coordinates as XY-Points or BiArcs.

Export the Cam Coordinates as TXT, DXF, STEP, or export the XY-Points or BiArcs directly to SolidWorks.

Add 2D-Cam