Kinematic Analysis Tools

We use these tools to show kinematic values at Master-Machine-Angle [MMA].

We can also plot the kinematic values for a complete machine cycle with a Graph FB.

tog_minusTool 1: Element-Properties dialog-box                                                        

The Element-Properties dialog-box is a list of the kinematic values for an element in different coordinate systems.

The kinematic values are for only at the Master-Machine-Angle [MMA]. However, you can move the model to any MMA while this dialog is open, to review the kinematic-values at a different MMA.

Elements that have Element Properties are:

Part, Pin-Joint, Slide-Joint, 2D-Cam, Part-Outline, Line, Circle, Arc, Point, Gear-Pair, Function-Blocks, Wire...

Example: The 'Point Element Properties' dialog-box is about to be opened to show its kinematic-properties.

To show the Elements Properties dialog-box:

In detail, In the graphic-area:

1.Hover [move your mouse-pointer above] any element so that it becomes red... [do not click the element ]
2.CTRL key down + Click the element

The Element-Properties dialog-box is now open.


The two steps above are frequently described as one step: Hover+CTRL+Click.


Note:

If you Hover+Ctrl+Click more than one element, the Element Properties dialog-box does not open. You must try again.
Element-Properties dialog-box : Point

Element-Properties dialog-box : Point

For Example: Element-Properties of a Point.

In this case, the Element Properties are of 'Point23', which is a child to Part3 [Element's Part], which is a child to Mechanism [Element's Mechanism].

Properties of a Point:

In the case of a Point, the properties are:

'Part Pos': the Point's vector position within the coordinate-system of the Part.
'Mech Pos': the Point's vector position within the coordinate-system of the Mechanism-Editor.
'Glob Position': the Point's vector position within the coordinate-system of the Model-Editor.
'Velocity', 'Acceleration':
oi , j : the magnitude of the vector's Velocity and Acceleration , in the X and Y directions, respectively
o|n| : the total magnitude of the vector's Velocity and Acceleration
oΘ :  the direction of the vector's Velocity and Acceleration . ['0' is the X-axis direction of the Mechanism-Plane]

'V' indicates they are 'vector' values.

tog_minusTool 2: Trace-Points                                                                                    

A Trace-Point shows the path of a Point on the Mechanism-Plane for a machine cycle.

Other terms for a Trace-Point are: locus, curve, and coupler curve.

You can show any number of Trace-Points.

Add Trace icon

To show a Trace-Point:

1.Click Kinematic-elements toolbar > Add Trace-Point
2.Click a Point in the graphic-area [usually a kinematically-defined chain]
3.Click OK-tiny-13-17 in the Command-Manager

Do 1-3 again to show more Trace-Points, as required.


Note: If, you do: 2. Right-Click a Point, the Command-Manager accepts the Point and the Trace-Point shows immediately.

Video : Add Trace-Point

 

Tutorial 2.B

Add Trace-Point

 

SELECT-ELEMENTS DIALOG-BOX

When there is more than one Point that is coincident with a different Point, the Select Elements dialog-box opens.

1.Click a Point in the Select Elements dialog-box
2.Click OK-tiny-13-17 to close the Select Elements dialog-box
3.Click OK-tiny-13-17 in the Command-Manager

Do 1-3 again for other Points. , in the same or different Parts.


To delete a Trace-Point

1.Click the Trace-Point in the graphic-area so that it becomes RED, and also shows in the Selection-Window
2.Click the 'delete' button on your keyboard.

- or -

2.Right-click the Point in the Selection-Window
3.Click 'Delete' in the contextual-menu

See also Mechanism Synthesis


Note:

If the Point:

1.Is a Point sketch-element - that is, it not a start-Point, end-Point, or centre-Point of the other types of sketch-elements
2.... AND does not have a dimension or constraint that limits its position in the Part-Editor
3.... AND has a Trace-Point...

...then, you can drag the Point [slowly] in the Mechanism-Editor and the Trace-Point will update.

The Point must satisfy ALL of 1 & 2 & 3 before it is possible to drag the point and trace-point in the Mechanism-Editor

tog_minusTool 3: Kinematic Vectors: Velocity and Acceleration

Dialog-PointVectors-VelAccSelected

To Show or Hide a Point's Velocity and Acceleration Vectors:

See How to open an element's dialog-box, , OR

In the graphic-area:

1.Double-click a Point on a Part that has a Green Part-Outline

The Point: Vectors and Position dialog-box opens.

2.Click Show or Hide Vectors
3.Click the Show Velocity Vector or Show Acceleration Vector, or the two check boxes

Accept the default Scope [Local], and Velocity Vector Options [Mag] [short for magnitude]


4.Click the OK-tiny-13-17 button to close the Point: Vectors and Position dialog-box.

Do 1-4 again to show the kinematic vectors of different Points, or to hide vectors for those Points that show vectors.


Note 1:

If necessary, change the colour of the graphic-area, or the vectors, to see more clearly the vectors and the kinematic-values

Application Settings > Colours tab > Graphic Colors > 'Background' button. .

Note 2:

You can double-click a velocity or acceleration vector to open this dialog-box.

Cycle (shortcut 'C') to see the vectors.

About the Velocity and Acceleration Vectors in the graphic-area

The vectors show only when the Point moves relative to the Mechanism-Plane
The length of the vectors are proportional to the Point's instantaneous Velocity and Acceleration.
The magnitude of the vectors shows at the arrowhead of each vector
The colour [default] of the vectors are Velocity, Acceleration
The vectors update their values and length each Machine-Step

Scope Option

The vectors are relative to the:

Local xyz axes - Mechanism Axes [default]
Global XYZ axes - mODEL-aXES

Velocity Vector Options

The Velocity vectors are the:

Magnitude of the Velocity [default]
X component of the velocity
Y component of the velocity

Velocity and Acceleeration Vectors from a Point.

To scale the vectors:

Force, Torque, Velocity, Acceleration Buttons to scale the vectors.

You can stretch or shrink the length of the vectors. Click the Velocity and the Acceleration (Accel.) buttons in the Feedback-Area.

1.Click the up button to increase the length of the vectors

- or -

1.Click the down button to decrease the length of the vectors

Top-Tip - make the vectors very short to see only the magnitude of the vectors near to the Point.

tog_minusTool 4: Dimensional Instant Scale                                                        
ALT + Click show the 'Instant Scale'

ALT + Click show the 'Instant Scale'

To show the Dimensional Instant Scale:

In the graphic-area:

1.ALT key down + Mouse-Click

The Instant-Scale shows next to your mouse-pointer.

As you zoom-in or zoom-out the scale also auto-scales.

There are 10 concentric circles.

There are two darker circles, which have the actual dimension value at their radius.

Middle Dark Circle [5]
Outer Dark Circle [10]

You can linearly interpolate the dimensions of the other circles.

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