Unit 19 Computer-aided Design and Manufacture

 

Unit 19:

Computer-aided Design and

 

 

Manufacture

 

Unit code:
M/601/1556

QCF level:
5


Credit value:
15






Aim

This unit will develop learners’ understanding of the practical applications of a Computer-aided Design and Computer-aided Manufacture (CAD/CAM) system.

Unit abstract

Most successful businesses invest substantially in research and development in order to gain competitive advantage. Engineering advances offer sales and marketing teams the ability to sell more products and gain a larger market share. In order to facilitate this, engineers must be able to quickly bring their designs to manufacture to achieve what is known as speed to market. The use of Computer-aided Design (CAD) has allowed engineers to communicate designs quickly. By making use of the geometry and details from CAD models, machines can be quickly and accurately programmed to produce high quality parts. These Computer Numerically Controlled (CNC) machines must receive information in a format that takes account of how part geometry will be achieved by the machining method, for example turning, milling or drilling. Computer-aided Manufacturing (CAM) software is available to accept CAD information. Combined with the knowledge of the engineer in order to sequence the tooling, this enables designs to progress to manufacturing in a relatively short time.

This unit will enable learners to produce component drawings using a CAD system specifically for transfer to a CAM system. They will also develop an understanding of structured data within CAD/CAM systems and the use of data transfer methods. Practical work will include the simulation of cutter paths on a CAM system and the production of a component from a transferred data file.

Learning outcomes

On successful completion of this unit a learner will:

1       Be able to produce a component drawing suitable for transfer onto a CAM system and produce a simple 3D surface

2       Be able to transfer data generated in CAD to a CAM system for subsequent machining

3       Be able to simulate the cutter paths on a CAM system to optimise the machining sequences

4       Understand how to transfer a generated tape file to a CNC machine and produce the component.


Unit content


1      Be able to produce a component drawing suitable for transfer onto a CAM system and produce a simple 3D surface

Component drawing: configure the hardware contained within a typical CAD workstation; produce CAD profiles using the more common types of editing facilities; geometry manipulation eg mirror, rotate, copy, array, offset; drawing attributes and structure with specific reference to associated profile data and parts listing

3D surface: use of world axis to produce geometry suitable for transfer to a CAM system; 3D surfaces generated for visualisation and subsequent machining

2      Be able to transfer data generated in CAD to a CAM system for subsequent machining

Transfer data: structured CAD data with reference to suitable datum and direction of lines; methods of transfer DYF and IGES; CAD layers used to help tooling sequences with consideration to tool changes


3      Be able to simulate the cutter paths on a CAM system to optimise the machining sequences

Cutting and tooling: tooling sequences optimised by using simulated cutting times generated within the CAM system; tooling data files containing calculated speeds and feeds to suit component material; cutting directions and offsets determined with due consideration for component accuracy and finish; clamping and general work holding safety considered with reference to clamping methods including program controlled clamping

CAM software: simulation of a range of cutter paths; component profiles; generation of cutter paths

4      Understand how to transfer a generated tape file to a CNC machine and produce the component

Generated tape file: offsets checked and setting values determined using MDI (manual data input) facilities to modify program where required; using buffer stores when applied to large amounts of program data; canned and repetitive cycles analysed and incorporated into the program when appropriate; sub-routines used for pockets, profiles and managed by the main program




Learning outcomes and assessment criteria


Learning outcomes
Assessment criteria for pass


On successful completion of
The learner can:


this unit a learner will:










LO1 Be able to produce a

1.1
produce a working drawing for subsequent manufacture


component drawing

1.2
demonstrate the significance of drawing attributes for


suitable for transfer onto a





CAD/CAM with specific reference to profile data and


CAM system and produce a






parts listing


simple 3D surface











1.3
produce a variety of geometrical shapes from datum in 3





dimensional space








LO2 Be able to transfer data

2.1
demonstrate the significance of structured data within a


generated in CAD to a CAM


CAD/CAM system


system for subsequent

2.2
create a DXF (data exchange file) from a standard


machining





drawing file









2.3
produce geometry within a CAM system through the use





of a DXF file







LO3 Be able to simulate the

3.1
generate cutter paths on a component profile through


cutter paths on a CAM


the use of suitable CAM software


system to optimise the

3.2
demonstrate how to obtain optimum cutting


machining sequences





performances by modifying generated cutter paths












LO4 Understand how to transfer

4.1
evaluate common methods of data transfer


a generated tape file to a

4.2
explain the process for inputting a program processed


CNC machine and produce





from CAM software to a CNC machine


the component











4.3
justify the method used for producing a component on a





suitable CNC machine.












Guidance

Links

This unit is designed to stand-alone, but can be linked to Unit 8: Engineering Design, Unit 14: Computer-aided Machining, Unit 15: Design for Manufacture, Unit 31: Value Management and Unit 69: Advanced Computer-aided Design Techniques.

Essential requirements

Centres delivering this unit must be equipped with industrial standard CAD/CAM software and hardware. The CAM software will be equivalent to SMARTCAM, MASTERCAM, ALPHACAM or APS. CAD software similar to ACAD, Release 13 and above would be considered adequate. Suitable machining centres with FANUC or HEIDENHAIN controllers or equivalent would be required also.

Employer engagement and vocational contexts

Centres should try to work closely with industrial organisations in order to bring realism and relevance to the unit. Visits to one or two relevant industrial or commercial organisations which use CAD/CAM techniques will be of value to enhance and support learning.

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