﻿ Getting Started Tutorials - MechDesigner > Tutorial 1: Add a Part that Rotates - a Crank

# Tutorial 1: Add a Part that Rotates - a Crank

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# Tutorial 1: Add a Part that Rotates - a Crank

## A Part that Rotates

 In a machine, a part that rotates (whose angle you control) can be a shaft, cam-shaft, indexing shaft, turret, star-wheel, rotary machine, ... . Also, it can be one Part in a more complex mechanism design. If it rotates with a constant angular motion, we use the name Crank. Kinematically, its name is Rocker.

### Objective of this Tutorial

 To add your first kinematic-chain that is kinematically-defined - a Part that rotates, whose angle you control with a Motion-Dimension FB. The Part rotates with constant angular velocity. To learn different methods to do each step. To learn some terminology.

### Terminology : the technical language for the different terms and elements in Tutorial 1.

Term :

Description

Plane :

The flat surface to which you add a Mechanism-Editor. The Front-View of each Mechanism-Editor is perpendicular to its XY-Plane.

Mechanism-Editor :

The graphics-area (workspace), contextual toolbars, and the Mechanism name-tab.

You add the kinematic-elements to the graphics-area of the Mechanism-Editors.

Part :

A Rigid-Body - represents a moving component in a machine.

Base-Part :

The Part that is fixed in each Mechanism-Editor. The local frame of a Mechanism-Editor.

Part-Outline :

The symbol that you click to select a Part. The Base-Part has a rectangular Part-Outline. The Parts you add to the model have an oval Part-Outline.

Joint :

The general term for an element that constrains the relative movement between two Parts.

Pin-Joint :

A joint that constrains two Parts to rotate relative to each other about a Point in each Part.

Kinematic-Chain :

Two or more Parts that you join with one or more Joints.

Kinematically-Defined :

Part or kinematic-chain whose Mobility=0. The Parts are solved.

Motion-Part :

A Part that is kinematically-defined, whose motion you control with a Motion-Dimension FB.

Function-Blocks :

Function-Blocks (FBs) control the motion of Motion-Parts. Connect Function-Blocks with wires. The wires transfer motion-values from the output of one Function-Block to the input of another.

Motion-Dimension FB :

A Function-Block (FB) that controls the motion of a Motion-Part.

Linear-Motion FB :

A Function-Block(FB) whose output follows the Master-Machine-Angle.

Gearing FB :

A Function-Block(FB) that uses a linear equation to transpose the motion at its input to give different motion-values at its output.

Master-Machine-Angle :

- also MMA - when you run your model, the MMA increases at a constant rate, 0-360, again and again.

Rocker :

A Motion-Part that rotates relative to a different Part.

Crank :

A Rocker that rotates continuously with a uniform motion. In the Kinematics-Tree, a Crank is a Rocker.