MechDesigner Reference & User Interface > 2.2 Mechanism-Editor: > Kinematic elements

Add Trace-Point

MD-Harmongraphs

Terminology:

Trace-Point :

A Trace-Point is the locus (the path) of a moving Point on the Mechanism-Plane over one machine-cycle.

Add Trace-Point does NOT add a Point to the model. You must select a Point that is in the model.

Add Trace-Point

Three example Trace-Points

STEP 1:Start the Add Trace-Point command

1.Mechanism-Editor: Add Menu > Mechanism sub-menu > Add Trace-Point

- or -

1.Mechanism-Editor: Kinematic-elements toolbar > Add Trace-Point

STEP 2:Click a Point

2.Click a Point* in the graphic-area.

E.g.: Points

* Start-Point, End-Point, center-Point, or Point.

See below, also: How to drag a Point with a Trace-Point.

If the Select-Element dialog-box opens, you have clicked more than one Point.

1.a. CTRL + click a Point in the Select-Elements dialog-box

1.b. Click to close the Select-Elements dialog-box

STEP 3: Complete the command

3.Click in the Command-Manager

The Trace-Point is now in the graphic-area.

Video:

How to drag a Point with a Trace-Point

Normally, when the Mechanism-Editor is active, you cannot move a sketch-element that is a child to a Part.

However, it is sometimes useful to search for a good Trace-Point, by moving the Point.

You can drag Points in the Mechanism-Editor if ALL of these conditions are met:

The Point must be a Point - that, is, it cannot be a start-Point, end-Point or center-Point.

IF...

In the Part-Editor:

a.You do: Part-Editor > Add Point

AND IF...

Also, in the Part-Editor

b.You do not add a dimension or a constraint to the Point

AND IF...

In the Mechanism-Editor:

c.You add a Trace-Point to the Point

Then, you can drag the Point and the Trace-Point in the Mechanism-Editor.

Note:

To drag the Point more easily:

•Reduce the Number-of-Steps to ~30 in the Machine Setting dialog-box

and / or

•Drag the Point and then keep the mouse-pointer very still until the Trace-Point moves.

To add a Trace-Point of a Point relative to a Part - NOT the Base-Part

Add a 2D-Cam.

The Point whose locus you want to see relative to a different Part is the center-Point of the Cam-Follower.

1.Edit the Part with the Point

2.Add a Circle with its centre-Point coincident with the Point.

3.Then, exit the Part-Editor

4.Add a Profile to the Circle

Add 2D-Cam - you must select two elements:

5.Cam-Part: Select the Part in which you want to show the Trace-Point

6.Follower Profile: Select the Profile of the Circle (see 1)

To show the Trace-Point

7.Edit the 2D-Cam (see 2D-Cam dialog-box) and show only the Pitch-Center

The locus of the Pitch-Centre is the Trace-Point of the Point relative to the Cam-Part