Introduction 2 Mechanical Design

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What is mechanical design?• Everything is designed except nature

• The packaging of a Band-Aid• The curve of a bike frame• The shape of a city street light

• Mechanical designs incorporate moving components into full assembly

• Include components like gears, bearings, linkages, screws• Static and dynamic design considerations

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Components

FastenersGears

BearingsMotors

http://www.mcmaster.com/

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Components

Bearings

http://www.mcmaster.com/

• Definition: Bearings occur between two materials moving relative to another

• Objective: Support relative motion to prevent wear, fatigue, etc.

• All different types• Bushing• Thrust bearing• Roller bearing• Ball bearing

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Components

http://www.mcmaster.com/

• Definition: Any pair of components that transmits/transforms torque and angular velocity

• Objective: To transmit torque and angular velocity across components

• All different types• Spur• Helical• Rack and pinion• Planetary

Gears

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Components

http://www.mcmaster.com/

• Definition: A component which fixes two materials together

• Objective: To fixture material together and to transmit loads between materials

• All different types• Bolts• Screws• Nuts• Washers

Fasteners

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Components

http://www.mcmaster.com/

• Definition: A component which transforms electrical to mechanical power

• Objective: Produce controllable and reliable rotational torque and motion

• All different types• DC motors• RC servos• Stepper motors• Brushless motors

Motors

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Computer Aided Design (CAD)• Used to create 3D models of mechanical designs

• Various software packages• Solidworks• ProEngineer• SketchUp

• Integrates various components into a single model• Build a perfectly scaled model• Import various components• Design connections, fastening, assembly, etc.

• Streamlines design process• Ensures fit and tolerances• Can be used with rapid prototyping machines

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SketchUp• Open source CAD software

• Free and paid versions• We will only require to use functions in the free version• Download here: http://www.sketchup.com/

• Easy to use tutorials • Getting Started with SketchUp tutorial today• Familiar and Expert in SketchUp for homework

• Huge library of premade CAD models• https://3dwarehouse.sketchup.com/index.html• Download and include in your own models

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Get Started With SketchUp – Part 1

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Rapid Manufacturing• Modern manufacturing method which uses CAD models to

fabricate physical components• Many methods

• Laser cutters (2D shapes)• CAD/CAM machining• 3D printing

• Fused deposition modeling (FDM)• Stereolithography• Direct metal laser sintering

• Increases efficiency in manufacturing• Allows for impossible geometeries• Complexity is free!

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Complexity is Free

http://www.citylifemagazine.ca/featured/the-3d-printing-revolution/13942

• Additive vs. Subtractive Manufacturing

• Orthogonal classical machining tools

• Layered geometries