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Step 5.3: The Motion-Dimension FB

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Motion-Dimension FB

A Motion-Dimension FB identifies a Part to which we can give a motion.

When we add a Motion-Dimension FB to a Part, we call the Part a Motion-Part.

There are two types of Motion-Parts:

•	Rocker = Part + Pin-Joint + Motion-Dimension FB

•	Slider = Part + Slide- Joint + Motion-Dimension FB

Key Learnings in this Step.

We add a Motion-Dimension FB to give a Slider and a Rocker.

Two values define the position of the Motion-Part.

Motion-Dimension = Base-Value + Motion-Values

•	Base-Value : we can edit it in the Motion-Dimension FB - it is the position of the Motion-Part without a wire at the input-connector.

•	Motion-values : the position (and velocity and acceleration) values at the input-connector

Add Motion-Dimension FB + Command-Manager

Kinematics-FB toolbar > Add Motion-Dimension FB

CM-AddMotionDim-A

The Command-Manager has three selection-boxes.

Click a Joint (Slide-Joint or Pin-Joint)

Click a solved Line or Point (in a Green Part)

Click an unsolved Line or Point (in a Blue Part*)

Notes:

are Lines if is a Pin-Joint

are Points if is a Slide-Joint

a Line or a Point in a Green Part

a Line or a Point in a Blue Part, a Free-Part

Motion Dimension FB + Graphic-Area

The icon of the FB in the graphic-area is different to the icon in the Kinematic-FB toolbar.
	The Motion-Dimension FB that identifies a Rocker
	The Motion-Dimension FB that identifies a Slider

General Procedures

Motion-Dimension FB and Rocker

Prepare the model so that these elements have these properties.

Element #

Element type

Rules

Pin-Joint

•	of two Points, with a Point from one Line in two different Parts , and

•	one Part must be a kinematically-defined Part

•	the other Part must be a free Part

Line

•	is a Line that radiates from the Point that specify the Pin-Joint (Element #1), and

•	in the kinematically-defined Part

Line

•	is a Line that radiates from the Point that references the Pin-Joint (Element #1), and

•	is in the free Part

GA-AddMotionDimRock-0

Preparation example:

•

Pin-Joint

•	The Points at Pin-Joint are at the ends of Lines.

•	Lines in two different Parts that radiate from two Points

•	Part is a kinematically-defined Part (Green Part-Outline).

•	Part is a free Part (Blue Part-Outline)

Kinematic FB toolbar > Motion-Dimension FB (right of Graphic-Area >>)

GA-AddMotionDimRock-1

Element #1: PIN-JOINT

The Pin-Joint is a joint between two Parts, and:

•	One Part is a kinematically-defined Part

•	One Part is a free Part

GA-AddMotionDimRock-2

Elements #2 and #3: LINES

Each Line must be a child to a Point that is also a child to the Pin-Joint (Element #1)

•	Element #2: a Line in the kinematically-defined Part

•	Element #3: a Line in the free Part

Click in the Command-Manager

GA-AddMotionDimRock3

Result: a Rocker

A Motion-Dimension FB to specify the angle between Lines, Elements #2 and #3

The dimension is an Orange colour in the graphic-area.

	- the icon in the graphic-area for a Rocker.
graphic-area is dark-grey

KT-Rocker

Kinematics-Tree for a Rocker

When we add a Motion-Dimension FB to a Pin-Joint, we identify it as a Rocker in the Kinematics-Tree.

The kinematic elements are:

•	'Part' + 'Pin-Joint' + 'Motion-Dimension' = 'Rocker'

Note: There are two different mouse-actions:

To move the

Function-Block :

Hover(FB) + DRAG

To move the

Motion-Dimension Line :

CTRL Key + Hover(FB) + DRAG

Hover(FB)= move your mouse above the FB icon.

DRAG = Mouse-Button-Down, and move your mouse-pointer, Mouse-Button-Up

Motion-Dimension FB and Slider

Prepare the model so that these elements have these properties.

Element #

Element type

Rules

Slide-Joint

•	of two Lines, one Line in each of two different Parts , and

•	one Part must be a kinematically-defined Part

•	the other Part must be a free Part

Point

•	the start-Point or the end-Point of the Line that references the Slide-Joint (Element #1)

•	that is in the kinematically-defined Part

Point

•	the start-Point or the end-Point of the free Line that references the Slide-Joint (Element #1)

•	that is in the free Part

GA-AddMotDim-Slider-0

Preparation example:

Two Parts

One is a kinematically-defined Part (Green Part-Outline)...the Base-Part

The other is a free Part (Blue Part-Outline)

2.	The Parts are Joined... with a Slide-Joint

Note the Points are the start-Points and end-Points of the Lines that are selected for the Slide-Joint

Kinematic FB toolbar > Motion-Dimension FB (right of Graphic-Area >>)

CM-AddMotionDimension-Slider1

Element #1: SLIDE-JOINT

The Slide-Joint is a joint between two Parts, and:

•	One Part is a kinematically-defined Part

•	One Part is a free Part

CM-AddMotionDimension-Slider3

Elements #2 and #3: POINTS

Each Point must be a child to a Line that is also a child to the Slide-Joint. (Element #1)

•	Element #2: a Point that is a start-Point or end-Point of a Line in the kinematically-defined Part

•	Element #3: a Point that is a start-Point or end-Point of a Line in the free Part

GA-AddMotDim-Slider-1

Click in the Command-Manager

Result: a Slider

The Motion-Dimension FB to specify the linear distance between Points, Elements #2 and #3

All Parts are now kinematically-defined Parts

The dimension is a Gold colour.

	<<< the icon in the graphic-area for a Slider
Note: This small image has a Dark Grey graphic-area

KT-Slider

Kinematics-Tree

When we add a Motion-Dimension FB to a Slide-Joint, we identify it as a Slider in the Kinematics-Tree.

The kinematic elements are:

•	'Part' + 'Slide-Joint' + 'Motion-Dimension' = 'Slider'

Note: Two different mouse-actions in the graphic-area

To MOVE the

Function-Block :

Hover(FB) + DRAG

To MOVE the

Motion-Dimension Line :

CTRL Key + Hover(FB) + DRAG

Hover(FB)= move your mouse above the FB icon.

DRAG = Mouse-Button-Down, and move your mouse-pointer, Mouse-Button-Up

Motion Dimension FB dialog box

Motion Dimension FB

You cannot specify the initial position of the Motion-Part as you add a Motion-Dimension FB.

To edit the initial position of the Motion-Part - we call it the Base-Value - we must open Motion-Dimension FB dialog-box.

To edit the Motion-Dimension FB:

1.	Double-click the Motion-Dimension FB in the graphic-area

The Motion-Dimension FB dialog-box opens.

Edit the:

o	Base-Value

- or -

o	Base-Value + Motion Value

It is best to think of the:

•	Base-Value as the position of the Motion-Part when a wire is not connected to the input-connector.

•	Base-Value + Motion-Value as the position of the Motion-Part when a wire is connected to the input-connector.

Directions separator, there are options to:

•	Edit the positive direction of the Base-Value

•	Edit the positive direction of the Motion-Values.

Use a Graph FB to display the values at the output-connector of a Motion-Dimension FB

STEP 1:

Add two Linear-Motion FBs to the graphic-area.

STEP 2:

Add a Graph FB to the graphic-area

STEP 3:

Connect a wire from the Linear-Motion FB(1) to the Graph FB X-axis (the bottom connector).

STEP 4:

Edit the Base-Part and add a Line

STEP 5:

Add a Part and a Pin-Joint to join one end of the Part to the end of a Line in the Base-Part.

STEP 6:

Add a Motion-Dimension FB to identify the Part as a Rocker.

STEP 7:

Connect the other Linear-Motion FB(2) to the Motion-Dimension FB, and from the Motion-Dimension FB to the Graph Y-axis

STEP 8:

Double-click Linear-Motion FB(2) ; edit the Phase Offset to 30

STEP 9:

Double-click Motion-Dimension FB ; edit the Base-Value to 110

STEP 10:

Double-click Graph FB to show the plot of the variables.

Function-Blocks-LinearOffsets

The image shows the elements in the graphic-area after Steps 1-10 - I have arrange the image to help

The Linear-Motion FB(1) adds 30 to the MMA.

We have connected a wire from the Linear-Motion FB(1) directly to Motion-Dimension FB

We have connected a wire from the Motion-Dimension FB directly to the Y1 input of the Graph FB.

The Motion-Dimension dialog-box and the Graph FB are open.

The Base-Value of the Motion-Dimension is 110º in the Motion-Dimension dialog-box.

The Master-Machine-Angle (MMA) is 120º

Thus, the output from the Linear-Motion FB is 120º + 30º = 150º.

Thus, the input to the Motion-Dimension FB = 150º.

The Base-Value is 110º.

Thus, the Rocker angle is at 110º + 150º = 260º.

The output from the Motion-Dimension FB is also the input to the Graph FB.

When you open the Graph FB, the vertical cursor is at the MMA.

If you set the cursor to 120º, the Y-axis value is 260º.

The Graph shows a plot of the output of the 'Motion-Dimension FB against the Linear-Motion FB(1)

The DRO shows the X-axis (cursor) is at 120º, the Y-axis Output is at 260º.

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