BTEC NATIONAL EXT DIPLOMA IN ENGINEERING
UNIT 17 – Computer Aided Drafting in Engineering (A/600/0267)
ASSIGNMENT ONE – CAD REPORT
LEARNER NAME
ASSESSOR NAME
N. Hodgson
HEALTH AND SAFETY LEGISLATION, REGULATIONS AND SAFE WORKING
DATE ISSUED
HAND IN DATE
SUBMITTED
PRACTICES
ON
IN FABRICATION
Criteria
P1 - Describe the advantages, compared to other
methods, of producing drawings electronically
using a CAD package
P2 - Describe the software and hardware required
to produce CAD drawings
M1 - Explain the relationship between CAD and
other software/hardware used in manufacturing
D1 - Justify the use of CAD in a manufacturing
company
Evidence
Feedback
Completion of
task 1
Completion of
task 2
Completion of
task 3
Completion of
task 4
This brief has been verified as fit for purpose
Internal Verifier
ANTHONY SPICER
Signature
A J Spicer
Date
17/08/2012
Student declaration
I declare that all the work submitted for this assignment is my own work or, in the case
of group work, the work of myself and the other members of the group in which I
worked, and that no part of it has been copied from any source.
I understand that if any part of the work submitted for this assignment is found to be
plagiarised, none of the work submitted will be allowed to count towards the
assessment of the assignment
Signed …………………………………… Date ……………………………………
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BTEC NATIONAL EXT DIPLOMA IN ENGINEERING
Assessor's comments
Qualification
Unit number and title
Assignment title
Edexcel Lev 3 National Diploma in
Engineering
Unit 17 – Computer aided drafting in
Engineering (A/600/0267)
Assessor name
N. Hodgson
Learner name
ASSIGNMENT ONE – CAD REPORT
Grading criteria
Achieved?
P1 - Describe the advantages, compared to other methods, of producing drawings electronically using a
CAD package
P2 - Describe the software and hardware required to produce CAD drawings
M1 - Explain the relationship between CAD and other software/hardware used in manufacturing
D1 - Justify the use of CAD in a manufacturing company
Learner feedback
Assessor feedback
Action plan
Assessor signature
Date
Learner signature
Date
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BTEC NATIONAL EXT DIPLOMA IN ENGINEERING
ASSIGNMENT OBJECTIVES
The aim of this module is to provide the learner with an
introduction to CAD and to enable them to produce
engineering drawings to given industry standards.
The purpose of this assignment is to provide a framework in which the learner will:

Be able to produce and interpret CAD drawings
ASSIGNMENT INTRODUCTION
Computer Aided Drawing (CAD) is now used extensively throughout the engineering
industry as a means of communicating drawing data to required standards. Two- and
three-dimensional representations of components can be drawn and modified allowing the
sharing of data from designer to customer. CAD data can be shared with CNC machines
and Computer Aided Manufacturing (CAM) software, which may then assist in improving
productivity, flexibility and quality of the final product.
During this assignment you are going to use computer-aided design to produce to number
of 2D CAD detail drawings that use a wide range of drawing commands and that meet
British Standards for Engineering drawings. These drawings will make up the majority of
the evidence for this assignment so it is important that you print these and keep them in
your folder of evidence.
TASK 1 – ADVANTAGES OF CAD
P1 - Describe the advantages, compared to other methods, of producing drawings
electronically using a CAD package
a. Produce a report in which you discuss the advantages of CAD over conventional drawing
techniques. The following sub-headings are for your guidance and may be used in order
to structure your report.
Quality of 3D representation
Explore the meaning of accuracy of part design using CAD. Include the Quality of
surfaces, triangulation of 3D models, accuracy of lines/ curves/ surfaces in models.)
Accuracy of 2D Part / Assembly Drawings
Discuss the accuracy of the 2D drawings created within CAD. This is the stage that would
most likely lead into manufacture. Take into consideration the model accuracy/
maximum chord height/ tolerance of ‘functional surfaces’, quality of drawings.
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BTEC NATIONAL EXT DIPLOMA IN ENGINEERING
The time taken from ‘Concept Idea to Manufacture’
Consider the ‘functionality’ of the software to be able to produce a production
component from a concept idea.
How long does it typically take to draw a 3D model/ build an assembly/ create a 2D
drawing? What is required to prepare a model for manufacture? A stage-by-stage list of
preferred methodology may be suitable to support your answer.
Discuss parametric modelling and the way a component is drawn in CAD to minimise the
effort required to modify geometry if necessary.
Identify ways that models can be created from standard part libraries, and subassemblies that may be common to a range of parts.
Discuss the opportunity some software has to reduce lead times by allowing collaborative
modelling from various Engineering sources (designer / manufacturing Engineer / Stress
Analysis / CNC Programming / Inspection)
Cost of software.
What is the cost of a licence (for industry/ commercial gain). Compare the cost against
the functionality across a range of CAD applications. Identify any additional costs for
increased functionality (kinematics / FEA analysis, Electrical wiring, etc)
Discuss the purpose of software licences and why they are prevalent.
Electronic transfer of information
Identify how the 3D / 2D models can be used with other software.
For example what are the necessary stages involved in exporting the models for use with
CAD/CAM, rendering software, animation software, finite element analysis (FEA).
Typical examples of ‘exported’ models include STL, IGES, DXF, DWG, STEP, etc.
What is the resultant file / what does it contain – for example a DXF file is 2D with only
lines and curved expressed as vectors. An STL is a faceted (triangulated) model in a
binary format with a degree of accuracy controlled by the ‘chord height)
Discuss the advantages and limitations of the models produced during the data exchange
process.
Other Methods of Drafting
Discuss the historic progression of designing parts and components. A good example of
this may be the ‘draughtsman’ and how traditionally the skills were in the production of
hand drawn orthographic views of components.
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BTEC NATIONAL EXT DIPLOMA IN ENGINEERING
What are the advantages of the ‘draughtsman’ approach? What similarities are still
apparent in the CAD software used now? What skills have been ‘lost’ or are ‘invaluable’
when designing an engineered component.
Discuss the impact the development of CAD has had on the role / necessity of Engineers
in a typical company. Discuss the large and small engineering companies and how the
engineers may be affected in the future.
What skills are now expected of an engineer above and beyond an understanding of
typical part design / manufacture?
TASK 2 – CAD SOFTWARE & HARDWARE
P2 - Describe the software and hardware required to produce CAD drawings
a. Software
Discuss the operating systems that the software is installed on (Windows / UNIX)
Identify the range of CAD software packages used by the ‘sectors of Engineering’. –
Automotive / Aerospace / Space / Nautical, etc. (Pro Desktop, Pro Engineer, Catia,
Pro/ENGINEER, Solidworks, AutoCAD, etc)
Compare at least two different CAD software applications and the functions / benefits /
opportunities. Give reasons why small / medium / large companies may chose one
particular system over another.
Identify the minimum system requirements that typical 3D CAD software requires to run
adequately. E.g. hard disk space, memory required, processor, video card.
b. Hardware
Identify the main types of hardware required and used during normal operation.
(Keyboard; mouse; other input devices e.g. light pen, digitiser, joystick, thumbwheel;
monitor; printer; other output devices e.g. plotter, rapid prototyping; storage e.g. floppy
disk, hard disk, memory stick, CD, network)
Discuss these benefits of additional devices and the contribution to the design cycle.
TASK 3 – RELATIONSHIP BETWEEN CAD & OTHER SOFTWARE
M1 - Explain the relationship between CAD and other software/hardware used in
manufacturing
Following your recent visit to the CAD design department at Leyland Trucks you are to
discuss how the linking of CAD to other software/hardware used within the company (i.e.
Oracle software, used in production management) has a key impact upon that
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BTEC NATIONAL EXT DIPLOMA IN ENGINEERING
organisation in terms of manufacturing (e.g. manufacturing efficiency, improving
production, reducing costs, reducing waste and reducing lead times).
Your report should also make reference to how Leyland trucks use concurrent Engineering
techniques in order to ensure the most efficient way of manufacturing their products and
how CAD is used within this.
Explore – Reducing lead times; reducing waste; reducing costs; manufacturing efficiency
TASK 4 – JUSTIFY THE USE OF CAD WITHIN A MANUFACTURING COMPANY
D1 - Justify the use of CAD in a manufacturing company
During your visit to Leyland Trucks that you will have seen first hand how the company
have made a significant investment in CAD.
For this task you should produce a report that justifies this investment in terms of its
benefits to this company as a whole giving particular consideration to the Design
department, Research and Development (R&D) departments and to the manufacturing
process as a whole. Consider the following points…..
What is the overview of the business and consider its historical approach to the design
and manufacture of its products (how were products designed and manufactured before
CAD was implemented).
Identify the key reasons as to why Leyland trucks have invested so heavily in CAD. Report
upon the extent to which the CAD application is used within the business. Are there
multiple CAD applications used? How is data transferred between the areas of the
business?
Consider how Leyland Trucks now uses CAD applications to control the manufacture of its
products.
Explain the impact (advantages & disadvantages) that CAD has had within all key areas
the business and identify any enhancements that you could see the company introducing
over the next few years (investment in future products)
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Research opportunities and Further Reading
http://en.wikipedia.org/wiki/Computer-aided_design
http://books.google.com/books?id=0SV5G8fgxLoC&printsec=frontcover&dq=Computer+Aid
ed+GEOMETRIC+DESIGN&source=gbs_summary_s&cad=0
(Handbook of Computer Aided Geometric Design )
http://machinedesign.com/article/changes-in-the-engineering-profession-over-80-years0407
(Changes in Engineering Profession Article)
http://machinedesign.com/ebook
(articles on CAD)
http://www.caduser.com/
http://www.quickparts.com/LearningCenter/WhatIsAnSTLFile.aspx
(what is in an STL file)
CAD Software
http://en.wikipedia.org/wiki/List_of_CAD_companies
www.ptc.com
Pro Engineer
www.3ds.com
Solidworks, CATIA
www.tatatechnologies.com
Reseller of software
http://www.autodesk.co.uk/
Autodesk Inventor
http://www.plm.automation.siemens.com/en_us/ Solid Edge
Comparison of CAD Software
http://en.wikipedia.org/wiki/Comparison_of_CAD_editors_for_CAE
Videos to Watch
http://www.solidworks.com/pages/programs/letsgodesign/
http://www.plm.automation.siemens.com/en_us/products/nx/design/video/feature_vid
eo.shtml
http://www.engineeringtv.com/
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