design
ENGG1100 Introduction to Engineering Design
Introduction to
Engineering Drawing
Professor Yunhui Liu
Dept. of Mechanical and Automation Engineering
Spring, 2014
MAE Dept., The Chinese University of Hong Kong
1
What is Engineering Drawing?
An engineering drawing is a type of technical drawing used to fully and clearly define requirements for engineered items (from en.wikipedia.org) • a formal and precise way (graphic language) for communicating information about the shape and size of physical objects.
• a mean for specifying the precision of physical objects.
Important as it is a legal document, i.e., if the drawings are wrong, it is the fault of the engineers! MAE Dept., The Chinese University of Hong Kong
2
Why ? Effectiveness of Engineering Drawing
1. Try to write a description of this object.
2. Test your written description by having someone attempt to make a sketch from your description. You can easily understand that …
The word languages are inadequate for describing the size, shape and features completely as well as concisely. MAE, CUHK
From Lec. Bhuiyan Shameem Mahmood
Graphic Language
Graphic language in “engineering applications” uses lines to represent the surfaces, edges and contours of objects.
The language is known as “drawing” or “drafting” .
A drawing can be done using freehand, instruments or computer methods.
From Lec. Bhuiyan Shameem Mahmood
5
Freehand drawing
The lines are sketched without using instruments other than pencils and erasers.
Example
From Lec. Bhuiyan Shameem Mahmood
6
Instrument drawing
Instruments are used to draw straight lines, circles, and curves concisely and accurately. Thus, the drawings are usually made to scale.
Example
From Lec. Bhuiyan Shameem Mahmood
7
Computer drawing
The drawings are usually made by commercial software
such as AutoCAD, SolidWorks etc.
Example
From Lec. Bhuiyan Shameem Mahmood
8
Introduction to
Engineering Drawing
Professor Yunhui Liu
Dept. of Mechanical and Automation Engineering
Spring, 2014
MAE Dept., The Chinese University of Hong Kong
1
What is Engineering Drawing?
An engineering drawing is a type of technical drawing used to fully and clearly define requirements for engineered items (from en.wikipedia.org) • a formal and precise way (graphic language) for communicating information about the shape and size of physical objects.
• a mean for specifying the precision of physical objects.
Important as it is a legal document, i.e., if the drawings are wrong, it is the fault of the engineers! MAE Dept., The Chinese University of Hong Kong
2
Why ? Effectiveness of Engineering Drawing
1. Try to write a description of this object.
2. Test your written description by having someone attempt to make a sketch from your description. You can easily understand that …
The word languages are inadequate for describing the size, shape and features completely as well as concisely. MAE, CUHK
From Lec. Bhuiyan Shameem Mahmood
Graphic Language
Graphic language in “engineering applications” uses lines to represent the surfaces, edges and contours of objects.
The language is known as “drawing” or “drafting” .
A drawing can be done using freehand, instruments or computer methods.
From Lec. Bhuiyan Shameem Mahmood
5
Freehand drawing
The lines are sketched without using instruments other than pencils and erasers.
Example
From Lec. Bhuiyan Shameem Mahmood
6
Instrument drawing
Instruments are used to draw straight lines, circles, and curves concisely and accurately. Thus, the drawings are usually made to scale.
Example
From Lec. Bhuiyan Shameem Mahmood
7
Computer drawing
The drawings are usually made by commercial software
such as AutoCAD, SolidWorks etc.
Example
From Lec. Bhuiyan Shameem Mahmood
8