Marks Distribution
QUESTION ONE (30Marks)
a) i) CAD stand for Computer-Aided Design and is any design activity that involves the
effective use of computers to create, modify, analyze, or document an engineering design,2
marks ✓.
ii) Design is the process of envisioning and planning the transformation of ideas into
desired objects or systems that are intended to satisfy certain societal needs, 2 marks ✓.
iii) Part Programming is the procedure of creating a series of coded numerical instructions
required to control machine tool. The coded instructions consist of letters, numbers and
symbols functionally arranged in form of blocks called G-and-M codes, 2 marks ✓.
b) Most Recognized CAD Formats are: 3 marks
IGES (Initial Graphics Exchange Specification)- was the first specification for CAD
data exchange published in 1980 as a NBS (National Bureau of Standards) report in USA.
All major CAD vendors support IGES and it is currently the most widespread standard for
CAD/CAM/CAE data exchange. ✓
DXF (Data eXchange Format)- was originally developed by Autodesk, Inc., the vendor
of AutoCAD. Its widely used to exchange 2D/3D wireframe data. ✓
STEP (STandard for the Exchange of Product model data)- is a new International
Standard (ISO 10303) for representing and exchanging product model information .it offers
different resources, e.g. geometric and topological representation, ✓.
c) Manual Part Programming: 4 marks
In order to perform Manual part programming, the machinist need to understanding the
following information: Machining operations and their sequence, cutting parameters such
as feed rete, feed, depth of cut and spindle speed, machine tool and its G-and-M codes
format and Required tool for each operation. ✓
Steps involved in Manual part Programming:
• Develop the 3D geometric model of the part using CAD software and generate
Orthographic Projections. ✓
• Create coded instructions in form of G-and -M codes and Download codes to the
appropriate machine either by USB Disc or through Machine Control Panel. ✓
• Test to verify the program on the actual machine and edit where necessary. ✓
• Run the program and produce the part. ✓.
d) Advantages of:
i) CAD; 4 marks
Increased design productivity—CAD reduces the time required to conceptualize and physically
draw product designs; ✓
–Increased available geometric forms in the design—CAD allows the designer to choose from
a range of geometrical shapes that would normally be outside the manual drawing process. ✓
1
, –Improved quality of the design—the use of a CAD system with appropriate hardware and
software capabilities permits the designer to do a more complete engineering analysis and to
consider a larger number and variety of design alternatives. The quality of the resulting design is
thereby improved. ✓
–Improved design documentation—the output of a CAD system results in better documentation
of the design than what is usually seen as practical in manual drafting. ✓
–Creation of a manufacturing database—by creating product design documentation, much of
the required database to manufacture the product is also created. ✓
–Design standardization—design rules can be included in CAD software to encourage the
designer to utilize company-specified models for certain design features. ✓.
ii) CAM, 3 marks
Computer-aided manufacturing introduces new technology. -Computer-aided
manufacturing reduces the amount of manual labor and does all the work in a fraction of
the time. ✓
Computer-aided manufacturing improves machine capabilities. -Computer-aided
design or CAD uses a variety of software programs to allow businesses to design 3D
models of their products. The precision of a CAD program can improve the optimization
process✓
Computer-aided manufacturing reduces errors. -Automated systems are less prone to
errors and can save a business a lot of financial investments. Businesses should do research
on various vendors for the machines that they desire. ✓
Computer-aided manufacturing increases productivity and efficiency. -A high-speed
machine means a shorter turnaround time. Businesses can move faster in the development
process and make changes at a faster rate. ✓
Computer-aided manufacturing reduces the waste of materials. -Many systems are
equipped to maximize the use of all materials at every step of the manufacturing process.
Computer-aided manufacturing systems are flexible-The flexibility of the machines allows
businesses to expand their services. ✓.
e) Part Modelling Marks Distribution 10 Marks
PART MODELLING & ASSEMBLY MARKS DISTRIBUTION
S/N DESCRIPTION MARKS Q1
i. Dimensional Accuracy 6 Marks 6 Marks ✓
ii. Material Application (x No. of Components) 2 Marks, (6 Marks) 1Marks ✓
iii. Part Configuration 1 Mark ½ Mark✓
iv. Mass Properties in (grams) 2 Marks✓ 1127.72 grams✓
v. Components Assembled 3 Marks
vi. Units ½ Mark ½ Mark✓
Total 10 Marks
2
QUESTION ONE (30Marks)
a) i) CAD stand for Computer-Aided Design and is any design activity that involves the
effective use of computers to create, modify, analyze, or document an engineering design,2
marks ✓.
ii) Design is the process of envisioning and planning the transformation of ideas into
desired objects or systems that are intended to satisfy certain societal needs, 2 marks ✓.
iii) Part Programming is the procedure of creating a series of coded numerical instructions
required to control machine tool. The coded instructions consist of letters, numbers and
symbols functionally arranged in form of blocks called G-and-M codes, 2 marks ✓.
b) Most Recognized CAD Formats are: 3 marks
IGES (Initial Graphics Exchange Specification)- was the first specification for CAD
data exchange published in 1980 as a NBS (National Bureau of Standards) report in USA.
All major CAD vendors support IGES and it is currently the most widespread standard for
CAD/CAM/CAE data exchange. ✓
DXF (Data eXchange Format)- was originally developed by Autodesk, Inc., the vendor
of AutoCAD. Its widely used to exchange 2D/3D wireframe data. ✓
STEP (STandard for the Exchange of Product model data)- is a new International
Standard (ISO 10303) for representing and exchanging product model information .it offers
different resources, e.g. geometric and topological representation, ✓.
c) Manual Part Programming: 4 marks
In order to perform Manual part programming, the machinist need to understanding the
following information: Machining operations and their sequence, cutting parameters such
as feed rete, feed, depth of cut and spindle speed, machine tool and its G-and-M codes
format and Required tool for each operation. ✓
Steps involved in Manual part Programming:
• Develop the 3D geometric model of the part using CAD software and generate
Orthographic Projections. ✓
• Create coded instructions in form of G-and -M codes and Download codes to the
appropriate machine either by USB Disc or through Machine Control Panel. ✓
• Test to verify the program on the actual machine and edit where necessary. ✓
• Run the program and produce the part. ✓.
d) Advantages of:
i) CAD; 4 marks
Increased design productivity—CAD reduces the time required to conceptualize and physically
draw product designs; ✓
–Increased available geometric forms in the design—CAD allows the designer to choose from
a range of geometrical shapes that would normally be outside the manual drawing process. ✓
1
, –Improved quality of the design—the use of a CAD system with appropriate hardware and
software capabilities permits the designer to do a more complete engineering analysis and to
consider a larger number and variety of design alternatives. The quality of the resulting design is
thereby improved. ✓
–Improved design documentation—the output of a CAD system results in better documentation
of the design than what is usually seen as practical in manual drafting. ✓
–Creation of a manufacturing database—by creating product design documentation, much of
the required database to manufacture the product is also created. ✓
–Design standardization—design rules can be included in CAD software to encourage the
designer to utilize company-specified models for certain design features. ✓.
ii) CAM, 3 marks
Computer-aided manufacturing introduces new technology. -Computer-aided
manufacturing reduces the amount of manual labor and does all the work in a fraction of
the time. ✓
Computer-aided manufacturing improves machine capabilities. -Computer-aided
design or CAD uses a variety of software programs to allow businesses to design 3D
models of their products. The precision of a CAD program can improve the optimization
process✓
Computer-aided manufacturing reduces errors. -Automated systems are less prone to
errors and can save a business a lot of financial investments. Businesses should do research
on various vendors for the machines that they desire. ✓
Computer-aided manufacturing increases productivity and efficiency. -A high-speed
machine means a shorter turnaround time. Businesses can move faster in the development
process and make changes at a faster rate. ✓
Computer-aided manufacturing reduces the waste of materials. -Many systems are
equipped to maximize the use of all materials at every step of the manufacturing process.
Computer-aided manufacturing systems are flexible-The flexibility of the machines allows
businesses to expand their services. ✓.
e) Part Modelling Marks Distribution 10 Marks
PART MODELLING & ASSEMBLY MARKS DISTRIBUTION
S/N DESCRIPTION MARKS Q1
i. Dimensional Accuracy 6 Marks 6 Marks ✓
ii. Material Application (x No. of Components) 2 Marks, (6 Marks) 1Marks ✓
iii. Part Configuration 1 Mark ½ Mark✓
iv. Mass Properties in (grams) 2 Marks✓ 1127.72 grams✓
v. Components Assembled 3 Marks
vi. Units ½ Mark ½ Mark✓
Total 10 Marks
2
