What is a 3D-Cam?

A 3D-Cam has complex surfaces that represent the cam-flanks. The rotational axes of the Cam and the Cam-Follower are usually perpendicular and offset.

Barrel, Cylindrical and Globoidal Cams are 3D-Cams.

Add 3D-Cam

Icon-Add3DCam

Machine Elements Toolbar : Add 3D-Cam

Menu:

Add menu > Mechanism sub-menu > Add 3D-Cam

GA-Add3DCam-Prep-0

Pre-amble:

You must prepare 5 elements in 3 different Mechanism-Editors. for a Barrel type Cam, and 4 Mechanism-Editors for a Globoidal type cam. See Preparation

When you do Add 3D-Cam, you will see five selection-boxes in the Command-Manager.

The five element you must select are, from top to bottom:

1.Part: Cam-Follower
2.Profile: Cam-Follower Roller
3.Part: Cam-Shaft [Green Part-Outline]
4.Profile: Cam-Blank
5.Line [sketch-element]: Cam-Blank Axis-of-Rotation

 

To see the five elements, you must use Tools menu (or toolbar) > Show other Part-Outlines and Sketches

Result:

The 3D-Cam shows in the graphic-area.

See also:

Tutorial 6C1: Oscillating-Follower / Barrel-Cam;
Tutorial 6C2: Indexing Follower / Globoidal-Cam

Note:

The 3D-Cam has 4 surfaces, which enclose the space volume you must cut from the Cam-Blank. You can edit the density of the points that make up the 4 surfaces with the 3D-Cam dialog-box

Four Surfaces

Two Cam Flanks - the active flanks of the roller, one each side of the Cam-Follower Roller
The root or 'floor' of the Cam. It is a surface between the edges of the 2 Cam-Flanks. It should not be in contact Cam-Follower Roller.
The surface that completes the rectangular cross-section. It joins the other edges of the 2 Cam-Flanks. This surface is normally 'outside' of the Cam-Blank.

Density of the Mesh

There are a number 'rims' along each flank. The 'rims' are equally-spaced across the flanks.
There are a number-of-points along each rim. The points are equally-spaced.

Use the 3D-Cam dialog-box to edit the number of rims and the number-of-points, to give the density of the mesh that defines the surfaces.

See Also:

3D-Cam dialog-box

tog_minus        Preparation before you can use the 'Add 3D Cam' command

GA-Add3DCam-Prep-0

We calculate a 3D-Cam from the relative movement of the elements. We model the elements in different Mechanism-Editors.

The 5 elements: Parts, Profiles and a Line are:

1s-redA Part in Mechanism 'B' : Cam-Follower
2sA Profile in Mechanism 'B' : Cam-Follower Roller
3sA Part in Mechanism 'A' :  the Cam Part
4sA Profile in Mechanism 'C': Cam-Blank
5sA Line [sketch] Axis in Mechanism 'C': the rotational axis of the Cam.

tog_minusHow to Add a 3D Cam

MD-3dBarrel-9a

Before we can use the Add 3D Cam command, we must see the five elements we need to click to complete the command - see images below

STEP 1: Click Visibility toolbar > Show other Mechanisms command

We must add the 3D-Cam to the Mechanism-Editor with the 'Cam-Part' - usually a rotating-Part.

It is best to rename the Mechanism-Editors when you model on different Planes. See Rename dialog-box

STEP 2: Click the Mechanism name-tab, with the 'Cam Part' [Note the name the Mechanism is 'BARREL' in the image to the left.

Icon-Add3DCam

STEP 3: View menu > Spin , to show the five elements you need to select.
STEP 4: Click Machine-Elements toolbar > Add 3D-Cam

CM-Add3DCam-2

The Command-Manager opens

It has five selection boxes.

STEP 5: Click the five elements in the graphic-area

You MUST click the elements in order, from top-to-bottom.

After you have selected the five elements :

STEP 6: Click the OK-tiny-13-17 in the Command-Manager

GA-Add3DCam-Prep-0

1r Part: Cam-Follower Part: Click the Grey Part-Outline of the Part

2r Profile: Cam-Follower Roller Profile: Click the Profile Contour (in Grey) for the Roller. [With 3D-Cams, the sketch for the Profile must be a circle]

3r Part: Cam Part: Click the Green Part-Outline in the active Mechanism-Editor

4r*Profile: Cam-Blank Profile*: Click the Grey Profile Contour

5r* Lines [sketch-element]: the axis-of-rotation of the Cam Blank: Click the Grey sketch-line

Notes:

Cam-Blank and Rotation-Axis

4s5s To transfer the 3D-Cam to SOLIDWORKS®, this sketch should be only:

a sketch-loop and Profile/Extrusion for the 'Cam-Blank'4s
a Line for the cam rotation axis5s.

Delete all other sketch-elements in the 'Barrel Blank' Part before you use transfer a Cam-Blank to SOLIDWORKS®. The shape does not need to replicate the cam-blank - but it helps.

Barrel Cam Example in MechDesigner

MechDesigner draws the 3D-Cam as a 'tube'.

The 3D-Cam is the 'negative' of a 'solid' Cam.

Use the 3D-Cam dialog-box to edit its parameters, and export it to SolidWorks®, or save it as a STEP file.

If you export the cam to SOLIDWORKS, the complete cam is built as a solid part.

I find it more convenient to save the 3D-Cam as a STEP file and import it to SolidWorks.

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