﻿ Getting Started Tutorials - MechDesigner > Tutorial 2A: Four-bar Kinematic-Chains

# Tutorial 2A: Four-Part kinematic-chains

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# Tutorial 2A: Four-Part kinematic-chains

## Four-bar Kinematic-Chains

 The four-bar mechanism is the basis of the most frequently used mechanism in a packaging machine.

### Objective of this Tutorial

 To add Parts, Pin-Joints, and Slide-Joints, which we combine in different ways to construct different types of four-bar mechanisms. To learn about dyads and dyad-closures.

#### Terminology for Tutorial 2

Term :

Definition

Four-bar :

A kinematic-chain with four(4) Parts and four(4) joints.

bar :

In the context of a four-bar, a bar is one of the four Parts.

Slide-Joint :

A kinematic-joint that constrains a Line is one Part to be collinear with a Line in a different Part.

Slider :

A Part whose position/motion we control with a Motion-Dimension FB - it is a Motion-Part

A dyad is a kinematic construction of:

2 Parts, and

3 Joints

A different way to assemble the two Parts in a dyad.

Motion FB :

A Function-Block(FB) that has a link to a Motion in MotionDesigner

Crank-Rocker :

Typically, a four-bar in which the input (the Crank) rotates at a uniform angular velocity, and the output (the Rocker) rotates and oscillates back-and-forth.

Crank-Slider :

Typically, a four-bar in which the input (the Crank) rotates at a uniform angular velocity, and the output (the Slider) slides and reciprocates back-and-forth.