Motion-Dimension FB

We have used the Motion-Dimension FB in Tutorial 1 and Tutorial 2.

Key Learnings in this Step.

Motion-Dimension FBs identify those Parts, and specify the motion of these Parts we call Motion-Parts.

The Motion-Dimension FB specifies the motion of a Part by the addition of two parameters:

Base-Value [a parameter in the Motion-Dimension FB dialog-box. The 'initial-value'] : a constant value. It specifies the position of the Part when you do not connect a wire to the input-connector of the Motion-Dimension FB .
Motion-values : continually change as a function of the Master Machine Angle [usually]. They are 'on the wire' at the input-connector to the Motion-Dimension FB.

Thus, these Motion-Parts move to the position as specified by [Base-Value + Motion-Values]/

Motion-Parts include:

Sliders
Rockers.

tog_minus        'Add Motion-Dimension FB' command

Icon-FB-MotionDimension

Kinematics-FB toolbar > Add Motion-Dimension FB

CM-AddMotionDim-A

The Command-Manager has three selection-boxes for three elements.

1s-redSelection-Box & Element 1: A Joint

2sSelection-Box & Element 2: Select a Solved Line or Point [in a 'Green' Part*]

3sSelection-Box & Element 3: Select an Unsolved Line or Point [in a Blue Part*]

2s3s are Lines if you select a Pin-Joint1s-red .

2s3s are Points if you select a Slide-Joint1s-red .

*2sA Solved Part is a kinematically-defined Part.  The Parts have a Green Part-Outlines

3sAn Unsolved Part is a Free-Part [NOT Kinematically Defined]. The Parts have Blue Part-Outlines.

tog_minus        Motion Dimension FBs in the graphic-area

The FB in the graphic-area becomes different to the FB in the Kinematic-FB toolbar.

Icon-FB-MotDim-Rocker

The Motion-Dimension FB in the graphic-area for a Rocker.

Icon-FB-MotDim-Slider

The Motion-Dimension FB in the graphic-area for a Slider.

tog_minus        ROCKER: Add a MOTION-DIMENSION FB to a PIN-JOINT

PREPARATION:

Part joined to the Base-Part

Part joined to the Base-Part


Part joined to a Rocker

Part joined to a Rocker

Refer to example images to the left, indicating the elements you must select.

Before you can add the Motion-Dimension FB, you must have, at minimum of:

1.Two Parts1s-red2s
One Part must be a kinematically-defined Part
It has a Green Part-Outline...
The Base-Part1s-red is an example

and

The other Part must be Free Part
It has a Blue Part-Outline2s
2.A Pin-Joint3s
It joins a Point from a Line4s5s in each of the two Parts1s-red2s
The Lines radiate (are rays) from the Pin-Joint3s.

Two examples to the left:

a Part joined to the Base-Part [TOP IMAGE]
a Part joined to a Rocker [ BOTTOM IMAGE]

SELECT ELEMENTS: Element 1: PIN-JOINT

CM-AddMotion-Dim-B

Click Kinematic-FB toolbar > Add Motion-Dimension FB

In the Command-Manager: You have the option to select a Pin-Joint or a Slide-Joint as the first element.

For the Part to become a Rocker, you must select a Pin-Joint.


Rule 1 [Rocker]

Element 1: is a Pin-Joint that joins a kinematically-defined Part to a Free Part

Rule 2 [rocker]

The Points that make the Pin-Joint must be at the ends of two Lines that radiate (are rays) from the Pin-Joint.

SELECT ELEMENTS: Elements 2 & 3: LINES

CM-AddMotionDim-C

After you select a Pin-Joint as Element 1, you must select Lines as Elements 2&3.


Rule 3 [rocker]

Element 2: a Line that radiates (is a ray) from the Pin-Joint and is a child to a kinematically-defined Part (The Part-Outline is Green)
Element 3: a Line that radiates (is a ray) from the Pin-Joint and is a child to a Free Part. (The Part-Outline is Blue)

Note: To end and place the Motion-Dimension FB icon in the graphic-area:

Left-Click the OK in the Command-Manager . The Motion-Dimension FB icon is at the left of the graphic-area, and not a very convenient place.

or

GOOD SHORTCUT - Right-Click with your pointer in the graphic-area. The Motion-Dimension FB icon is near to your mouse-pointer - much more convenient.

 

RESULT: The Motion-Dimension FB and a Pin-Joint.

GA-MotionDimension-ROCKER

GA-MotionDimension-ROCKER2

The 'Free-Part' becomes a Rocker and kinematically-defined, with a Green Part-Outline, after you click OK-tiny-11-15 in the Command-Manager.


Two examples of a Rocker in the images to the left.

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

A Rocker is a Motion-Part.

Icon-FB-MotDim-Rocker

Icon for a Rocker in the graphic-area.


To edit the Base-Value [start-position] of the Rocker, open the Motion-Dimension FB dialog-box.

1.Double-click the Motion-Dimension FB1s-red

- or -

1.Double-click the Motion-Dimension dimension-line2s or dimension-arrowhead [Not the dimension value itself]

- or -

See How to Open a Dialog-Box

Note: After you add the Motion-Dimension FB, you may want to move the FB or the Motion-Dimension to a more convenient place in the graphic-area:

To move the Motion-Dimension Function-Block : Hover + Drag the Function-Block
To move the Motion-Dimension dimension : CTRL+Hover+Drag the arrowhead of the Motion-Dimension.

Video

 

Tutorial 1: Step 1.5

Add a Motion-Dimension FB
Edit a Motion-Dimension FB

 

tog_minusSLIDER: Add a MOTION-DIMENSION FB to a SLIDE-JOINT

PREPARATION

Motion-Dimension-Slide1Joint1

Your model must have:

1.Two Parts1s-red2s

Before you add the Motion-Dimension FB, the Parts are:

A kinematically-defined Part (Green Part-Outline)...[for example, the Base-Part1s-red]

and

A Free-Part (It has a Blue Part-Outline)2s

The Slide-Joint joins a Line4s5s in the two Parts [see 1]

Note: The arrowhead 6s shows the Positive direction of the Slide-Joint.

SELECT ELEMENTS: Element 1: SLIDE-JOINT

CM-AddMotionDim-SJ-A

 

Rule 1 [slider]

Element 1: is a Slide-Joint3s that joins a kinematically-defined Part to a Free Part

 

Rule 2 [slider]

You must select Points as the Elements 2&3

The Points must be at the ends of the Lines that make the Slide-Joint you select as the Element 1

SELECT ELEMENTS: Elements 2&3: POINTS

CM-AddMotionDim-SJ-B

After you select a Slide-Joint as Element 1, you must select Points as Elements 2&3.

Rule 3 [slider]

Element 2: a Point at one end of the Line that was selected for the Slide-Joint AND is a child to a kinematically-defined Part (The Part-Outline is Green)
Element 3: a Point at one end of the Line that was selected for the Slide-Joint AND is a child to a Free Part. (The Part-Outline is Blue)

 


The 'Free-Part' becomes a Slider and kinematically-defined, with a Green Part-Outline, after you click OK-tiny-11-15 in the Command-Manager.

RESULT: The Motion-Dimension FB applied to a Slide-Joint.

MotionDimensionD

We call the Part a Slider after you have added the Motion-Dimension FB.

A Slider is a Motion-Part.

Icon-FB-MotDim-Slider

The Motion-Dimension FB icon for the Slider in the graphic-area.

To edit the initial position of the Slider, use the Motion-Dimension FB dialog-box.

Double-click the Motion-Dimension FB

- or -

Double-click the Motion-Dimension arrowhead or dimension

 

 

Notes:

To move the Motion-Dimension Function-Block:

Hover + Drag the Motion-Dimension Function-Block

To move the Motion-Dimension:

CTRL+Hover+Drag the arrowhead of the Motion-Dimension.

 

tog_minus        The Motion Dimension FB dialog box

Motion Dimension FB

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.

2.Edit the:
oBase-Value 1s-red [ the Base-Value text is missing!]

The Base-Value should be above the dimension box '47.438903'...! at the Top of the Motion-Dimension dialog-box.

- or -

oBase-Value + Motion Value 2s

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.

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

STEP 1: Add TWO Linear-Motion Function-Blocks to the graphic-area.
STEP 2: Add a Graph FB to the Mechanism graphic-area
STEP 3: Connect the Linear-Motion FB to the Graph FB X-axis (the bottom connector).
STEP 4: Edit the Base-Part to Add a Line - See Step 1.3
STEP 5: Add a Part (Step 1.2) and Add a Pin-Joint (Step 1.4) 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 Added-Part as the Part we will specify an angle relative to the Line in the Base-Part.
STEP 7: Connect the other Linear-Motion FB to the Motion-Dimension FB, and from the Motion-Dimension FB to the Graph Y-axis
STEP 8: Double-click the Linear-Motion FB: Edit the phase to 30
STEP 9: Double-click the Motion-Dimension FB, Edit the Base-Value of the Motion-Dimension to 110
STEP 10: Double-click the Graph FB to open the Graph.

QST6-2-4

The image shows the elements in the graphic-area after Steps 1-10.

 

The 'top' Linear-Motion FB1s-red adds 30 to the MMA.

We have connected a wire from the Linear-Motion FB directly to Motion-Dimension FB2s

We have connected a wire from the Motion-Dimension FB directly to the Y1 input of the Graph FB3s.

The Motion-Dimension dialog-box4s and the Graph FB5s are open.

The 'Base-Value' of the Motion-Dimension is 110º6s 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.

 

This means the input to the Motion-Dimension FB = 150º.

The Base-Value for the Motion-Dimension 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 red cursor is at the MMA.

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

The Graph shows a plot of the output of the 'Motion-Dimension FB against the 'bottom' Linear-Motion FB(0 to 359º)

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

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