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

Trace-Point

Terminology:

Trace-Point :	the locus, or path, of a moving Point* relative to the Mechanism-Plane for one machine-cycle.
* Point, start-Point, end-Point, center-Point, Motion-Point

MD-Harmongraphs

Add Trace-Point

Add Trace-Point does NOT add a Point to your model.

You must select a Point * that is already in your model.

* Point, start-Point, end-Point, center-Point, Motion-Point.

Three example Trace-Points

STEP 1:Start the Add Trace-Point command

1.Mechanism menu > Trace-Point

1.Kinematic elements toolbar > Add Trace-Point

STEP 2:Click a Point

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

For example, in the image, Points

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

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

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

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

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

STEP 3: Complete the command

3.Click in the Command-Manager

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

Video:

How to drag a Trace-Point

Normally, when the Mechanism-Editor is active, you cannot drag a sketch-element.

However, as a special-case, you can move a Point** with a Trace-Point, if the Point does not have any constraints.

In this special case, it is easier to search for a “good” Trace-Point.

** not a start-Point, end-Point, center-Point or Motion-Point

To drag a Point in the Mechanism-Editor:

In the Part-Editor:

1.Do Add Point

Do not add a dimension or a constraint to the Point

2.Exit the Part-Editor

In the Mechanism-Editor:

3.Do Add Trace-Point and select the Point

4.Drag the Point!

Note:

To make it easier to drag the Point:

•Reduce the Number-of-Steps to ~60 - see Machine Setting dialog

and / or

•Drag the Point but do not lift your mouse-pointer until the Trace-Point also moves

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

A Trace-Point is the locus of a Point in a moving Part relative to the Base-Part. To see the locus of a Point in a moving Part relative to a different moving Part, you can add a 2D-Cam, and show only the path of the Pitch-Center.

1.Edit the Part with the Point whose locus you want to see relative to a moving Part.

2.Add a Circle, and add a Coincident constraint between the center-Point of the Circle and the Point.

3.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 locus of the Point

6.Follower Profile: Select the Profile of the Circle

To show the locus of the Point

7.Edit the 2D-Cam.

8.In 2D-Cam dialog > Display tab > Cam-Visibilities > Enable Pitch-Center.

The locus of the Pitch-center is the locus and Trace-Point of the Point relative to the Cam-Part.