Summary of this Step

A 2D-Cam is a child to a Part. Thus, we must add the Part for the Cam.

This Cam is to rotate at constant-angular velocity. See Tutorial 1.

In this Step:

1.We add a rotating Part to represent the shaft for the cam - or the 'cam-shaft'.

tog_minus        Video of this Step

 

Tutorial 6A-5

tog_minus        Add the cam-shaft

QST5-5-1a

In Step 6A.3, we added a Line1s-red in the Base-Part.

The Point, at the left-side of the Line, is to locate the Pin-Joint and centre of the cam-shaft.

Question: Do you remember why we need a Line in the Base-Part, and not only a Point?

Answer: Because, a cam-shaft is kinematically a 'Rocker' (a Crank).

A 'Rocker' has a Motion-Dimension FB to define its angular position. A 'Rocker' Part needs a Line from which to specify its angular position. Thus, we added a Line in the Base-Part.

See also Tutorial 1, Step 5

QST5-5-2a

Add the Line and the Pi-Joint

STEP 1: Click Add Part in the Kinematic-elements toolbar

It is possible to add a Pin-Joint at the same time as we add the Part.

In this case, before you mouse-button-down and drag to add the Part :

STEP 2: Hover above a Point1s-red so that only the Point becomes red

When ONLY the Point is RED:

STEP 3: Mouse-button-down and drag to add the Part.

Notes:

•Only use this Hover technique to add a Part and Pin-Joint when there is only one Point.
•If the Line and the Point is red when you hover, you will add a Part and Slide-Joint.

QST5-5-3a

Step 3 is complete.

Cam-shaft Part-Coordinates.

You can choose to calculate Cam-coordinates with Mechanism-Coordinates or Part-Coordinates – see Step 6A.8

To calculate with Part-Coordinates correctly, connect the Origin of a cam-shaft to the Base-Part.

Now, add a Motion-Dimension FB to specify the motion of the Part - so that it becomes a Crank.

QST5-5-4a

Add a Motion-Dimension.

STEP 4: Click Add Motion-Dimension FB from the Kinematic-FB toolbar.
STEP 5: Click the elements in the selection-boxes of the Command-Manager - from top to bottom:
a) Click the Pin-Joint1s-red that joins the Part (cam-shaft) to the Base-Part
b) Click the Line2s in the Base-Part that radiates from the Pin-Joint – see Step 6A.3
c) Click the Line3s in the new Part (cam-shaft)

The Part-Outline becomes green – it is a kinematically-defined Part.

STEP 6: Connect the Linear-Motion FB4s to the Motion-Dimension FB5s [Connect is 'Drag a wire from...to....']
STEP 7: Run > Cycle the kinematic-chains.

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