BRX210 BRX210 ‘Mechanical ‘Mechanical

Blueprint Reading’Blueprint Reading’Unit #1Unit #1

Drawings and PrintsDrawings and Prints

After studying this unit, you After studying this unit, you will be able to:will be able to:

Explain the difference between Explain the difference between drawings and printsdrawings and prints

Explain the advantages of CAD Explain the advantages of CAD drawingsdrawings

Describe print making processesDescribe print making processes Handle prints correctlyHandle prints correctly

DrawingsDrawings

Two types:Two types: 1. Machine drawings1. Machine drawings

Used to produce one unique partUsed to produce one unique part 2. Assembly drawings2. Assembly drawings

Used to show how different parts are Used to show how different parts are connectedconnected

Hand DraftingHand Drafting

Creation of drawings using pencils, Creation of drawings using pencils, triangles, straightedges, and other triangles, straightedges, and other drafting toolsdrafting tools

It is a very time consuming processIt is a very time consuming process Few drawings are created this way Few drawings are created this way

todaytoday

Computer-Aided Drafting Computer-Aided Drafting (CAD)(CAD)

Created using computer softwareCreated using computer software Several components of a CAD system:Several components of a CAD system:

CPU (Central Processing Unit)CPU (Central Processing Unit) Main body of the computerMain body of the computer Where the information is stored and Where the information is stored and

processedprocessed MonitorMonitor

Screen used to view the drawingScreen used to view the drawing KeyboardKeyboard

Used to input text and numbersUsed to input text and numbers

Digitizer (Mouse)Digitizer (Mouse) Input device used to control an on-screen Input device used to control an on-screen

cursorcursor PlotterPlotter

Used to create the actual physical drawing Used to create the actual physical drawing on paperon paper

ModemModem Used to transfer information between Used to transfer information between

computers anywhere in the worldcomputers anywhere in the world

CAD AdvantagesCAD Advantages

Increased productivityIncreased productivity More accurate drawingsMore accurate drawings Easier drawing storageEasier drawing storage Easier drawing managementEasier drawing management

PrintsPrints

A print is a copy of a drawingA print is a copy of a drawing Prints can be made quicker and more Prints can be made quicker and more

affordable than plotted drawingsaffordable than plotted drawings Often, the term ‘blueprint’ is used Often, the term ‘blueprint’ is used

instead of ‘print’instead of ‘print’ Blueprint – older method with dark blue Blueprint – older method with dark blue

background and white lines and symbolsbackground and white lines and symbols Two methods of creating prints:Two methods of creating prints:

PhotocopyingPhotocopying Diazo processDiazo process

Engineering CopiesEngineering Copies

Use an electrostatic process to Use an electrostatic process to reproduce drawingsreproduce drawings

Similar to common copier machinesSimilar to common copier machines Designed to handle larger size drawingsDesigned to handle larger size drawings

Diazo ProcessDiazo Process Still used today though slowly being Still used today though slowly being

replaced by the faster engineering replaced by the faster engineering copierscopiers

Diazo process is a photochemical process Diazo process is a photochemical process using light and chemicals (ammonia) to using light and chemicals (ammonia) to produce drawingsproduce drawings

Often referred to as ‘bluelines’ due to Often referred to as ‘bluelines’ due to blue lines on white backgroundblue lines on white background

Always exact duplicates of the original Always exact duplicates of the original and much sharper than engineering and much sharper than engineering copiescopies

Care of Drawings and Care of Drawings and PrintsPrints

Original drawings should be stored Original drawings should be stored in a safe placein a safe place

Protect from:Protect from: WaterWater WeatherWeather OilOil

Always roll and fold properlyAlways roll and fold properly