MechDesigner Reference & User Interface > Dialogs > Dialog: Function-Block: Motion-Path

To open the Motion-Path dialog

1.Double-click the Motion-Path FB in the graphics-area

OR

1.See How to Open a dialog

MD-DIALOG-MOTIONPATH-PT-PARAMS-PT-PARAMS

# Motion-Points: | Default = 1

To edit the number of Motion-Points along the sketch-loop.

1.Increase or decrease the # of Motion-Points

2.Click button . at the bottom of Point Parameters separator.

Motion-Points distribute equally along the Phase-Range and Length-Range of the sketch-loop.

If there is a Pin-Joint between a Part and a Motion-Point, you must add the Pin-Joint again.

Phase Range | Default = 360 which is equivalent to the total length of the sketch-loop

Linear-Range | Default = Length of the sketch-loop.

When # Motion-Points >1, the Motion-Points are distributed equally along the Phase-Range and Linear-Range of the sketch-loop.

1.Edit the Phase Range (deg)

OR

1.Edit the Linear Range (mm)

When you edit Phase-Range, the Linear-Range updates automatically, and vice-versa.

These two parameters indicate the proportion of the sketch-path over which to distribute Motion-Points (when # Motion-Point >1).

These parameters distribute Motion-Points (when # Motion-Points > 1) over a range (length) that is different to the total-length of the sketch-path.

The distribution of the Motion-Points is best illustrated with examples. We urge you to EXPERIMENT.

Example

Say : Actual length of a sketch-loop is 120.0mm

The Number of Motion-Points = 3

Default: Phase-Range =360 (and Linear-Range = 120.0)

The 3 Motion-Points are equally spaced over 120.0mm. The distance between each Motion-Point = 127.5/3 =40.5mm

Position of Motion-Point #1 = 0mm, Motion-Point #2 = 42.5mm, and Motion-Point #3 = 85.0mm

Edit Phase-Range = 120 (and Linear-Range = 42.5)

The 3 Motion-Points are distributed over a linear-length of 127.5/3 = 42.5mm

The distance between each Motion-Points is 42.5/(3-1) = 21.25mm

Position of Motion-Point #1 = 0mm, Motion-Point #2 = 21.25, and Motion-Point #3 = 42.5mm

Phase Offset (deg) | Default = 0

Linear Offset (mm) | Default = 0

Phase Offset and Linear Offset move ALL of the Motion-Points along the sketch-loop. The offset value indicate the position of Motion-Point #1 when the motion-value at the input-connector of the Motion-Path FB is equal to 0; or when a wire is not connected to its input-connector.

Phase-Offset: equates the length of the sketch-loop to 360 degrees of a circle.

Linear-Offset: equates the length of the sketch-loop to its actual linear length.

Example - we urge you to EXPERIMENT.

A sketch-loop is 127.5mm long. There is 1 Motion-Point.

•A Phase-Offset=40 (deg) moves the Motion-Point #1 to 127.5×40 ∕ 360=14.16mm along the sketch-loop. All other Motion-Points move by the same distance.

•A Linear-Offset=40 (mm) moves the Motion-Point #1 to 40mm along the sketch-loop. All other Motion-Points move by the same distance.

button

If you edit the Number of Motion-Points parameter, you must click the Regenerate Motion-Points button.

Headers: Name | Index | Phase (read-only)

•Name : the element-name of each Motion-Point.

If you click on a Motion-Point in the list, it shows as the Selected-Color in the graphics-area.

•Index : the number of the Motion-Point

•Phase : the relative displacement along the sketch-path, relative to the Motion-Point #1

Display Motion-Point #1 as

You can show the position of Motion-Point #1 on the sketch-loop.

◉Show Nothing - nothing shows above the Motion-Point #1 in the graphics-area

◉Show Distance - the linear position of Motion-Point #1 as it moves along the sketch-loop

◉Show Phase - the angular phase of Motion-Point #1 as it moves along the sketch-loop.

You can select a dimension to control the length of the sketch-loop that is associated with the Motion-Path FB.

The dimension you select is the Control-Dimension - see Note 1

Important

In the Part-Editor, the sketch-loop should be fully defined before you select the Control-Dimension.

Then, as you edit the Control-Dimension, the shape of the sketch-loop is more predictable - see Note 1

MD-Dialog-MotionPathFB-LengthControl-Control

/

To control the length of the Motion-Path with a Dimension:

1.Click the Button

The Part-Editor opens.

2.Click a dimension that can control the total length of the sketch-loop - see Note 1

The Part-Editor closes.

The name of the Control-Dimension is now under the button.

For example, DimPtoP2

When you do not want to control the length of the Motion-Path with a dimension:

1.Click

Note 1: control-dimension. The control-dimension is a Linear dimension in the Part-Editor.

The dimension you should select has rules.

The Control-Dimension must be.

DimPtoP#	the distance between two Points
DimL#	the length of a Line

The control-dimension Must Not be:

DimPtoL#	the perpendicular distance form a Point to a Line, or a Point to the X-axis, or a Point to the Y-axis
DimLtoL#	the distance between two parallel Lines
AnglePPP# AngleLtoL#	an angle
	Gray before you select it. For example, a Design-Set already controls the dimension.

Parameters

Control-Dimension Length - read-only

The active value of the Control-Dimension.

Actual Path Length - read-only

The active length of the sketch-loop associated with the Motion-Path FB.

Target Path Length

Edit the length (use small changes) of the sketch-loop associated with the Motion-Path FB - see Note 2

If the Spin-box tool does not show, double-click in the data-box.

Control-Dimension Min / Max - see Note 3 below

When you select the Control-Dimension:

•Control-Dimensions Minimum is estimated as 0.5 × Control-Dimension - see Note 3.

•Control-Dimensions Maximum is estimated as 2.0 × Control-Dimension - see Note 3.

If required:

Edit the Control-Dimension Minimum and Maximum limits - see Note 2.

MD-Dialog-MotionPathFB-LengthControl-Belt

Belt-Tooth-Pitch

The Belt-Tooth-Pitch does not change the belt length.

The diameter of a Pulley is a function of the number of teeth AND Belt Tooth-Pitch.

See Pulley dialog

Note 2: Target Path-Length

Edit the Target Path-Length with small increments. If the Actual Path Length does not change, see Note 3

Note 3: Control-dimension min and/or MAX

Message in Feedback-Area (below the graphics-area)

MD-FeedbackMsg - ControlDimensionMin too samall

The default values for the Control-Dimension Min or Control-Dimension Max are such that the Actual-Path Length can be equal to the Target Path Length.

However, it is possible that the Root-Finding Math is confused!

To reset the Root-finding Math:

•Increase or decrease the Control-Dimension Min/MAX, then try to edit the Target-Path-Length again.

•You may need to edit these values to be almost equal to the actual length of the Control-Dimension.

Information coming with MD17

The position and motion of Motion-Points along the sketch-loop is a function of the Data-Type at the input-connector to the Motion-Path FB.

The Data-Type at the input-connector must be Linear or Rotary.

Data-Type = Linear

The position of the Motion-Point #1 along the sketch-loop has a scale of: 1mm at input = 1mm along sketch-loop

the position of the Motion-Point #1 along the sketch-loop = motion-value at input-connector(mm)

Data-Type = Rotary

The position of Motion-Point #1 along the sketch-loop has a scale of: 1deg at input = Length of sketch-loop / 360

∴ the position of the Motion-Point #1 along the sketch-loop = motion-value at input-connector(degrees) × (Length of the sketch-loop /360)

The Motion-Point moves along the total length of the sketch-loop when the input is 360.

Dialog: Function-Block: Motion-Path

Dialog: Function-Block: Motion-Path

Motion-Path FB

Point Parameters tab

Length Control tab

MOTION-PATH AND DATA TYPES