Why use a Motion-Path Function-Block?

Motion-Path FB

You add a Motion-Path FB to a sketch-element, MechDesigner adds a Motion-Point to the sketch-element* at its start-Point.

The motion-values at the input-connector to the Motion-Path FB specify the motion of the Motion-Point along the sketch-element.

Applications of a Motion-Path FB and Motion-Points include to:

define the path of a robot,
define the path of a chain or belt, and also
define the motion for Ram-R and Ram-P dyads.

The sketch-element is: one sketch-element, or open sketch-path, or a closed sketch-loop. The sketch-loop may be 'crossed (8)' or 'not-crossed (0)'.

Add Motion-Path FB

Toolbar :

Kinematics FB toolbar

Add Motion-Path FB

Motion-Path FB

Menu :

Add menu > Add Motion-Path FB

Dialog :

Motion-Path dialog-box

Add :

STEP 1: Add the Motion-Path Function-Block to a sketch-path and graphic-area
1.Click Add menu [toolbar] > Add Motion-Path FB

The Command-Manager has one selection-box.

2.Click a sketch-element, sketch-path in the graphic-area
3.Click OK-tiny-13-17 in the Command-Manager

The Motion-Path FB is now in the graphic-area

There is a Motion-Point at the start-Point of the sketch-element you select in the sketch-path.

Open :

STEP 2: Open the Motion-Path dialog-box
1.Double-click a Motion-Path FB in the graphic-area

- or -

The Motion-Path FB dialog-box is now open.

Dialog :

Motion-Path FB dialog-box

Notes :

Do not add sketch-elements to a Motion-Point. You should add sketch-elements to a Part that you join to the Motion-Point with a Pin-Joint.

Scaling of the Motion for the Motion-Point along the Motion-Path FB

The motion of the Motion-Point along the sketch-path is a function of the Data-Type at the input-connector to the Motion-Path FB: Are they Linear or Rotary units?

When you connect a wire from the output of a Motion FB to the input of a Motion-Path FB the motion of the Motion-Point is a function of the Output Data Type as set in the Motion FB dialog-box.

Motion FB > Output Data Type

There are three Output Data Types

Motion - do not use with a Motion-Path FB
Linear - see below
Rotary - see below

Motion FB > Output Data-Type - Linear

The position of the Motion-Point is scaled on a 1 : 1 basis with the motion-value that output-connector of the Motion FB and input-connector its Motion-Path FB

∴ the position of the Motion-Point along the sketch-path = motion-value at input-connector in linear units.

Motion FB > Output Data-Type - Rotary

The sketch-path has a scale of 0 to 360. A motion-value at the input of 360 would move the Motion-Point the complete extent of the sketch-path.

∴ the position of the Motion-Point along the sketch-path = motion-value at input-connector × total length of the sketch-path / 360

Compare : Motion-Path FB and Motion-Dimension FB

A Motion-Path FB / Motion-Point can be compared with a Motion-Dimension FB / Motion-Part.

Function-Block :

Motion-Path FB <

> Motion-Dimension FB

Motion Element :

Motion-Point <

> Motion-Part

Constraint :

Sketch-Path <

> Joint

Input :

Motion-Values at its input-connector <

>Motion-Values at its input-connector

RESULT :

Motion of a Motion-Point constrained by a sketch-element <

> Motion of a Motion-Part constrained by a joint

Tutorials and Reference Help Files for MechDesigner and MotionDesigner 14.2 + © Machine, Cam, Mechanism, and Motion Design Software by PSMotion Ltd