B. Tech. (Mechanical Engineering)
Semester-VI 2025
Computer Aided Manufacturing
Paper No. ME-601
Assignment 1
Unit-1
1. Explain and differentiate among the following.
2. (I.) Continuous, mass, batch and job shop production
3. (II.) Point to Point, straight cut and continuous path control
4. (III) Fixed, Programmable, Flexible automation
5. (IV) Open loop and Closed loop positioning system
6. (V) Conventional Product cycle and Product cycle with CAD/CAM
7. (VI) Define Automation, types and automation strategies, merits and demerits
8. (VII) Coordinate system of NC machines, Axis designation
9. (VII) Applications of NC in metal-cutting and non-metal cutting areas.
10. ABC company designed a new product line to build in a new plant. The new line possesses
100 various products types. The company decides to produce 10,000 units annually of each
product type. The products average 1000 components each, and the average number of
processing operations needed for each component is 10. Each processing operation needs
average one minute time. Each worker works 8 hr per shift for 250 days per year (2000 hr
per year). Find 1. How many products, 2. How many parts, and 3. How many workers will
be needed in the factory.
11. The break-even point is to be determined for two production methods, one a manual
method and the other automated. The manual method requires two workers at $9.00/hr
each. Together, they produce at a rate of 36 units/hr. The automated method has an initial
cost of $125,000, a 4-year service life, no salvage value, and annual maintenance costs =
$3000. No labor (except for maintenance) is required to operate the machine, but the power
required to run the machine is 50 kW (when running). Cost of electric power is $0.05/kWh.
If the production rate for the automated machine is 100 units/hr, determine the break -even
point for the two methods, using a rate of return = 25%.
Unit-2
12. Discuss Control resolution, accuracy and repeatability.
13. Discuss elements of a CNC machine.
14. Explain principles of various AC servomotors, DC servomotors, Stepper motors, Linear
Motors, resolvers, inductions optical grating and encoders.
15. Explain principles of PLCs, Block diagrams of CNC operations, Nomenclature, types and
features of CNC machine tools, Elements of CNC Lathe and Milling machines and
systems, Machine control unit.
16. Explain Position control, Velocity control and its significance
17. A CNC machine possesses a closed-loop positioning system with the worktable driven by
a ball screw having pitch=6.0 mm. The ball screw is linked to the output shaft of a stepper
motor using a gearbox with gear ratio 5:1(five turns of motor for each turn of screw). The
optical encoder develops 48 pulses/rev of its output shaft. The table is needed to move a
distance of 250 mm at a feed rate =500 mm/min. Estimate (1) how many pulses are needed
to be received to verify movement of the table with exact 250 mm distance, (2) the pulse
rate of encoder, (3) the required drive motor speed to achieve the desired table feed rate.
18. A CNC machine employs an open loop positioning system with the worktable driven by a
ball screw having pitch=6.0 mm. The ball screw is linked to the output shaft of a stepper
motor using a gearbox with gear ratio 5:1. Number of step angles of the stepper m otor are
48 step angles. The table is needed to move a distance of 250 mm from its current position
with a linear velocity=500 mm/min. Estimate (1) how many pulses are needed move the
table the specified distance (2) the required motor speed and pulse rate to achieve the
desired table velocity.
B. Tech. (Mechanical Engineering)
Semester-VI 2025
Computer Aided Manufacturing
Paper No. ME-601
Assignment 2
Unit-3
1. Explain tool nomenclature of indexable carbide Turning tool inserts and tool holder.
2. Describe various component of CNC Milling tooling system with a neat sketch? What is
the role of Retention Knob in CNC Milling tooling system?
3. Explain APT part programming and programming using Pro-E.
4. Discuss the steps involved to develop a proven NC part program with a neat sketch. A
turning operation is to be performed on an NC lathe. Cutting speed = 2.5 m/s, feed = 0.2
mm/rev, and depth =4.0 mm. Workpiece diameter = 100 mm and its length = 400 mm.
Determine (a) rotational speed of the Workbar, (b) feed rate, (c) metal removal rate, and
(d) time to travel from one end of the part to the other.
5. Explain CNC program structure. A numerical control drill press drills four 10.0 mm
diameter holes at four locations on a flat Aluminium plate in a production work cycle.
Although the plate is only 12 mm thick, the drill must travel a full 20 mm vertically at each
hole location to allow for clearance above the plate and breakthrough of the drill on the
underside of the plate. Cutting conditions: speed = 0.4 m/s and feed = 0.10 mm/rev. Hole
locations are indicated in the figure below. All coordinates in figure are in mm. The drill
starts out at point (0,0) and returns to the same position after the work cycle is completed.
Travel rate of the table in moving from one coordinate position to another is 500 mm/min.
Owing to effects of acceleration and deceleration, and time required for the control system
to achieve final positioning, a time loss of 3 s is experienced at each stopping position of
the table. Assume that all moves are made so as to minimize the total cycle time. If loading
and unloading the plate take 20 s (total handling time), determine the time required for the
work cycle.
6.
Write coordinates in absolute and incremental system
7. Write a manual part program for machining component below. Profile depth = 2 mm,
Billet size = 100x100x10, Material = Aluminium, Tool diameter = 5 mm, speed = 1500
rpm, Feed = 30 – 50 mm/min
8. Write a manual part program for machining component below. Profile depth = 1 mm.
Billet size = 100x100x10, Material = Aluminium, Tool diameter = 5 mm, speed = 1500
rpm, Feed = 30 – 50 mm/min
9. Write a manual part program for machining component below. Profile depth = 3 mm.
Billet size = 100x100x10, Material = Aluminium, Tool diameter = 5 mm, speed = 1500
rpm, Feed = 35 – 45 mm/min
10. Write a manual part program for machining component below. Profile depth = 3 mm.
Billet size = 100x100x10, Material = Aluminium, Tool diameter = 5 mm, speed = 1500
rpm, Feed = 35 – 45 mm/min
11. Write a manual part program for machining component below. Profile total raw depth of
cut = 3 mm. Billet size = as given in drawing, Material = Aluminium, Rough cut: speed =
1200 rpm, Feed = 35 mm/min; Finish cut: speed = 1450 rpm, Feed = 25 mm/min
12. Write a manual part program for machining component below. Profile total raw depth of
cut = 3 mm. Billet size = as given in drawing, Material = Aluminium, Rough cut: speed =
1200 rpm, Feed = 35 mm/min; Finish cut: speed = 1450 rpm, Feed = 25 mm/min
Unit-4
13. Explain various elements of Turning centre and machining centre.
14. Discuss various elements and mechanism of Automatic Pallet changer and Automatic tool
changer with neat figures. What is tool presetting and Modular Tooling?
15. Discuss various requirements of structure in the case of CNC machine tools.
16. What is function of Guideways in CNC machine? What is difference between conventional
Guideways and CNC Guideways? Explain with neat diagrams.
17. What is function of lead screw in CNC machine? What is difference between conventional
lead screw and ball recirculating screw? What are advantages of ball recirculating screw?
18. Discuss spindle design features of Turning centre.
19. Explain various elements of the Coordinate Measuring Machine and Machine vision
system.
20. Describe functions of Machine vision system with neat figure.
21. CMM is used to measure three point locations on the flat surface of a part. The coordinates
of three point locations in mm are (112.11, 75.12, 20.08), (7.12, 70.46, 19.15), and (6.28,
11.37, 19.01). The coordinates have been corrected for probe radius. (i) Determine the
equation for the plane of the flat surface of the part. (ii) To evaluate flatness of the surface,
a fourth point measured by the CMM has coordinates (60.11, 37.17, 19.13). if fourth point
(60.11, 37.17, Z4) is estimated from the perfectly flat plane equation determined in (i),
What is Z4? (iii) What is the vertical deviation of fourth point determined from the
perfectly flat plane equation in (i)?
22. The coordinates of the intersection of two lines are to be determined using a CMM to define
the equations for the two lines. The two lines are the edges of a machined part, and the
intersection represents the corner where the two edges meet. Both lines lie in the x-y plane.
Measurements are in inches. Two points are measured on the first line to have coordinates
of (5.254, 10.430) and (10.223, 6.052). Two points are measured on the second line to have
coordinates of (6.101, 0.657) and (8.970, 3.824). The co ordinate values have been
corrected for probe radius. (a) Determine the equations for the two lines in the form of Eq.
(23.7). (b) What are the coordinates of the intersection of the two lines? (c) The edges
represented by the two lines are specified to be perpendicular to each other. Find the angle
between the two lines to determine if the edges are perpendicular?
23. All numerical problems solved in class.
B. Tech. (Mechanical Engineering)
Semester-VI 2025
Computer Aided Manufacturing
Paper No. ME-601
Assignment 3
Unit-5
1. Compare fixed position layout, process layout, Product layout and group technology layout
with neat figures. What are part family and machine cell in cellular manufacturing? How
are these formed? Explain composite part with neat diagrams.
2. What is independent and dependent demand? Explain basic components of MRP with neat
diagrams.
3. Explain the differences between monitor and control of a system. Explain Factory physical
activities and information processing activities with neat figures.
4. What is computer-aided process planning? Discuss the two basic approaches in computeraided process planning with neat diagrams.
5. Discuss CAD, CAM and CIM including their elements with neat figures.
6. Discuss definition Robot, types of joints in industrial robot, configuration of industrial
robot, typical configuration of wrist assembly of industrial robot, degree of freedom of
industrial robot with neat figures.
7. Write short notes on PLC, MRP, AGV, FMS with neat diagrams.
8. A robot performs a loading and unloading operation for a machine tool. The work cycle
consists of the following sequence of activities:
Seq.
No.
1
2
3
4
Activity
Robot reaches and picks part from incoming conveyor and
loads into fixture on machine tool
Machining cycle (automatic)
Robot reaches in, retrieves part from machine tool, and
deposits it onto outgoing conveyor
Move back to pick-up position
Time
(sec)
5.5
33
4.8
1.7
Every 30 workparts, the cutting tools in the machine must be changed. Cutting tool change
irregular cycle takes 3.0 minutes to accomplish. The uptime efficiency of the robot is 97%;
and the uptime efficiency of the machine tool is 98%, not including interruptions for tool
changes. These two efficiencies
are assumed not to overlap (i.e., if the robot breaks down, the cell will cease to operate, so
the machine tool will not have the opportunity to break down; and vice versa). Downtime
results from electrical and mechanical malfunctions of the robot, machine tool, and fixture.
Determine the hourly production rate, taking into account the lost time due to tool changes
and the uptime efficiency.
9. A robot with a double gripper performs a loading and unloading operation for a machine
tool. The work cycle consists of the following sequence of activities:
Seq.
No.
1
2
3
4
5
Activity
Time
(sec)
Robot reaches and picks raw part from incoming conveyor 3.3
in one gripper and awaits completion of machining cycle.
This activity is performed simultaneously with machining
cycle.
At completion of previous machining cycle, robot reaches 5
in, retrieves finished part from machine, loads raw part into
fixture, and moves a safe distance from machine.
Machining cycle (automatic).
33
Robot moves to outgoing conveyor and deposits part. This 3
activity is performed simultaneously with machining cycle.
Robot moves back to pickup position. This activity is
performed simultaneously with machining cycle.
1.7
Steps 1, 4, and 5 are performed simultaneously with the automatic machining cycle. Steps
2 and 3 must be performed sequentially. Every 30 workparts, the cutting tools in the
machine must be changed. Cutting tool change irregular cycle takes 3.0 minutes to
accomplish. The uptime efficiency of the robot is 97%; and the uptime efficiency of the
machine tool is 98%, not including interruptions for tool changes. These two efficiencies
are assumed not to overlap (i.e., if the robot breaks down, the cell will cease to operate, so
the machine tool will not have the opportunity to break down; and vice versa). Downtime
results from electrical and mechanical malfunctions of the robot, machine tool, and fixture.
Determine the hourly production rate, taking into account the lost time due to tool changes
and the uptime efficiency.
10. All numerical problems solved in class.