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 Parts that we want to move with a specified motion.

These Parts are called Motion-Parts.

Base-Value [a parameter in the Motion-Dimension FB dialog-box. The 'initial-value'], is the position of the Motion-Part when you do not connect a wire to the Motion-Dimension FB's input-connector.
The motion-values are 'on the wire' at the Motion-Dimension FB's input-connector.
The Motion-Part moves to the positions as specified by the addition of the 'Base-Value' and '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.

Selection-Box & Element 1: A Joint1s-red

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

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

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 FB in the graphic-area for a Rocker.

Icon-FB-MotDim-Slider

The FB in the graphic-area for a Slider.

tog_minus        Add a Motion-Dimension FB to a Pin-Joint

PREPARATION: Before you can 'Add a Motion-Dimension FB' to a Pin-Joint:

Part joined to the Base-Part

Part joined to the Base-Part


Part joined to a Rocker

Part joined to a Rocker

Refer to images to the left:

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.
a Part joined to a Rocker

SELECT ELEMENTS: Select the First Element: 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.


First Rule:

The Pin-Joint must join a kinematically-defined Part to a Free Part

SELECT ELEMENTS: Select the Second and Third Elements: LINES

CM-AddMotionDim-C

When you select a Pin-Joint as the first element, you must select Lines as the second and third elements.


Second Rule:

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

Third Rule:

As the second and third elements, you must select the Lines that radiate (are rays) from the Pin-Joint .

Also, from Rule One:

One Line4s is a child to a kinematically-defined Part (The Part-Outline is Green)
The other Line5s is a child to a Free Part. (The Part-Outline is Blue)

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

Note: Placement of the Motion-Dimension FB icon in the graphic-area w

To you complete the command 'Add Motion-Dimension FB:

Click the 'OK OK in the Command-Manager, to put the Motion-Dimension FB icon at the left-side of the graphic-area.
Right-Click, after you have selected all elements, to put the Motion-Dimension FB icon near to your mouse-pointer as you Right-Click

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

^^Rocker joined to BasePart ^^

^^Rocker joined to BasePart ^^

^Rocker Joined to a different Rocker^

^Rocker Joined to a different Rocker^

Refer to the two examples of a Rocker in the images to the left:

We call the Part a Rocker. A Rocker is a Motion-Part.

Icon-FB-MotDim-Rocker

The Rocker icon in the graphic-area.

Edit the start position [Base-Value] of the Rocker with the Motion-Dimension FB dialog-box.

To open the Motion-Dimension FB dialog-box, you can:

Double-click the Motion-Dimension FB1s-red

- or -

Double-click the Motion-Dimension arrowhead or dimension2s

- 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 itself, or the two, 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 : Add a Motion-Dimension to a Pin-Joint

tog_minus        Add a Motion Dimension FB to a Slide-Joint

PREPARATION: Before you can use Add Motion-Dimension with a Slide-Joint

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: Select the First Element: SLIDE-JOINT

CM-AddMotionDim-SJ-A

 

First Rule:

The Slide-Joint3s must join a kinematically-defined Part to a Free Part

SELECT ELEMENTS: Select the Second and Third Elements: POINTS

CM-AddMotionDim-SJ-B

When you must select a Slide-Joint as the first element.

Second Rule:

You must select Points as the second and the third elements
The Points must be at the ends of the Lines that make the Slide-Joint you select as the first element.

Also, from Rule One:

One Point4s is a child to a kinematically-defined Part (The Part-Outline is Green)
The other Point5s is a child to a Free Part. (The Part-Outline is Blue)

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

Video: Add a Motion-Dimension to a Slide-Joint

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