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PANIMALAR ENGINEERING COLLEGE
Department of Mechanical Engineering
ME8793 PROCESS PLANNING AND COST ESTIMATION
•
125
ME8793: PROCESS PLANNING &
COST ESTIMATION
IV/7TH SEM
OBJECTIVES:
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To introduce the process planning concepts to make cost estimation for various
products after process planning
UNIT I INTRODUCTION TO PROCESS PLANNING
9
Introduction- methods of process planning-Drawing interpretation-Material evaluation –
steps in process selection-.Production equipment and tooling selection
UNIT II PROCESS PLANNING ACTIVITIES
9
Process parameters calculation for various production processes-Selection jigs and fixtures
election of quality assurance methods - Set of documents for process planning-Economics of
process planning- case studies
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UNIT III INTRODUCTION TO COST ESTIMATION
9
Importance of costing and estimation –methods of costing-elements of cost estimation –
Types of estimates – Estimating procedure- Estimation labor cost, material cost- allocation of
over head charges- Calculation of depreciation cost
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UNIT IV PRODUCTION COST ESTIMATION
9
Estimation of Different Types of Jobs - Estimation of Forging Shop, Estimation of Welding
Shop, Estimation of Foundry Shop
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UNIT V MACHINING TIME CALCULATION
9
Estimation of Machining Time - Importance of Machine Time Calculation- Calculation of
Machining Time for Different Lathe Operations ,Drilling and Boring - Machining Time
Calculation for Milling, Shaping and Planning -Machining Time Calculation for Grinding
OUTCOMES:
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TOTAL: 45 PERIODS
Upon the completion of this course the students will be able to
CO1 select the process, equipment and tools for various industrial products.
CO2 prepare process planning activity chart.
CO3 explain the concept of cost estimation.
CO4 compute the job order cost for different type of shop floor.
CO5 calculate the machining time for various machining operations.
TEXT BOOKS:
1. Peter scalon, “Process planning, Design/Manufacture Interface”, Elsevier science technology Books,
Dec 2002.
2. Sinha B.P, “Mechanical Estimating and Costing”, Tata-McGraw Hill publishing co, 1995.
REFERENCES:
1. Chitale A.V. and Gupta R.C., “Product Design and Manufacturing”, 2nd Edition, PHI, 2002.
2. Ostwalal P.F. and Munez J., “Manufacturing Processes and systems”, 9th Edition, John Wiley, 1998.
3. Russell R.S and Tailor B.W, “Operations Management”, 4th Edition, PHI, 2003.
4. Mikell P. Groover, “Automation, Production, Systems and Computer Integrated Manufacturing”,
Pearson Education 2001.
5. K.C. Jain & L.N. Aggarwal, “Production Planning Control and Industrial Management”,
Khanna Publishers 1990.
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PANIMALAR ENGINEERING COLLEGE
Department of Mechanical Engineering
12
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UNIT I: INTRODUCTION TO PROCESS PLANNING
PART - A
1. Define process planning?
Process Planning is defined as the systematic determination of methods by which a
product is to be manufactured economically and competitively.
2.
What are the aims and objectives of process planning?
• Identify the functions involved in product design and manufacture;
• Define the process planning activity;
• Identify and describe the main tasks undertaken during process planning;
• Identify and describe the various data used in process planning;
• Identify and describe the main process planning documentation;
• Identify and describe the relationship between process planning and
other Manufacturing functions.
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3.
4.
State the objectives of Drawing interpretation?
• identify appropriate supplementary information from the drawing to aid
the process planning;
• identify and interpret dimensional information from the drawing;
• identify and interpret geometric information from the drawing;
• identify the critical processing factors for the component from the
dimensional and geometric information.
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What are responsibilities of Process Planning Engineer?
• Interpreting part print analysis, and symbols.
• Gathering the fundamental details of product design c) Selecting the
machining processes.
• Selecting proper machining with allied tooling.
• Sequencing the operations.
• Deciding on the inspection equipment in order to meet the desired quality.
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What are the benefits of CAPP?
• Process rationalization and standardization: CAPP leads to more
logical and consistent process plans than manual process planning.
• Productivity improvement: As a result of standard process plan, the
productivity is improved (due to more efficient utilization of resources such
as machines, tooling, stock material and labour).
• Product cost reduction: Standard plans tend to result in lower
manufacturing costs and higher product quality.
• Elimination of human error
• Reduction in time: As a result of computerizing the work, a job that used
to take several days, is now done in a few minutes.
• Reduced clerical effort and paper work
• Improved legibility: Computer prepared route sheets are neater and easier
to read than manually prepared route sheets.
• Faster response to engineering changes: Since the logic is stored in the
memory of the computer, CAPP becomes more responsive to any changes
in the production
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parameters than the manual method of process planning.
• Incorporation of other application programs: The CAPP program can be
interfaced with other application programs, such as, cost estimating and
work standards.
6. State the aims and objectives of Production equipment and tooling selection
• Identify and describe the main factors in the selection of production
equipment;
• Select appropriate production equipment for a given problem;
• Identify and describe the main factors in the selection of tooling;
• Select appropriate tooling for a given problem.
7. List any three cutting tool materials in the order of increase in hardness.
• High speed steel
• carbide
• diamond
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8. State the difference between routing sheet and operation list?
Routing sheet: It specifies the route the raw material follows through the
manufacturing environment. It usually lists the production equipment and
tooling to be used.
Operation list: Once the routing of a component has been established, the
detailed plan for every operation can be prepared using an operations list. This
specifies in more detail each individual operation. It is usual for an operations list
to be prepared for each workstation listed on the routing sheet, although it may
sometimes cover a group of machines in a work cell.
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9. What are the most influential factors in terms of tool performance.
• Tool material
• Geometry
• The use of cutting fluids.
10. State the inputs and outputs of Process Planning.
Inputs
• Method study
• Work measurements
• Machine manufacturer data
• Tool manufacturer data
• capability study
• Process improvement
Outputs
• Route sheet
• Operation sheet
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Part-B (13 Marks)
1. Explain Design manufacturing cycle with the help of block diagram.
2. Explain various methods of CAPP system.
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Department of Mechanical Engineering
3.
4.
5.
6.
7.
8.
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Explain material selection and evaluation method in detail.
List and explain the information used in drawing interpretation.
Explain machine selection method.
Explain the factors affecting tool performance and explain the tool selection method.
Explain process selection factors and process selection method in detail.
Explain Engineering drawing in detail.
UNIT II PROCESS PLANNING ACTIVITIES
1. What is quality assurance?
Quality assurance (QA) is a way of preventing mistakes or defects in
manufactured products and avoiding problems when delivering solutions or
services to customers; which ISO 9000 defines as "part of quality management
focused on providing confidence that quality requirements will be fulfill.
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2. What are the main reasons for using jig and fixture?
• Components can be produced quicker;
• Greater interchangeability is obtained due to repeatability of manufacture
which subsequently reduces assembly time;
• Accuracy can be easily obtained and maintained;
• Unskilled or semi-skilled labour.
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3.
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What are the difference between jig and fixture?
JIG
It is a work holding device that holds,
supports and locates the work piece and
guides the cutting tool for a specific
operation
FIXTURE
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It is a work holding device that holds,
supports and locates the work piece for
a specific operation but does not guide
the cutting tool
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Jigs are not clamped to the drill press table Fixtures should be securely clamped to
unless large diameters to be drilled and the table of the machine upon which the
there is a necessity to move the jig to bring work is done.
one each bush directly under the drill.
4. State the various process parameters used in various machining process.
• Speed
• feed
• depth of cut
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5. Define break even analysis.
Break Even Analysis is a process of relating the profit, volume and cost. it is nothing
but no profit no loss.
6. State the various inspection system
• 100 % inspection
• Sampling inspection
 Gate sampling inspection
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
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1.
2.
3.
4.
5.
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Patrol inspection
First off inspection
Statistical Process Control(SPC)
Statistical sampling
PART-B (13
MARKS)
Explain the method of selecting jig or fixture for a particular process.
List and explain the factors to be considered for selecting quality assurance method.
List the documents needed for process planning.
What is meant by control charts. where it is used .
Explain break even analysis in detail and derive an expression for break even
quantity.
PART-C (13
MARKS)
Prepare and operation and route sheet for the component shown in figure.
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1.
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2. A bolt can be produced either by capstan late or CNC lathe. In capstan lathe, time
taken is 1 hour and overhead cost is 50% of labour cost. In CNC lathe time taken is 5
hours for 100 products and overhead cost is 120% of labour cost. The material cost
of each product is Rs. 60 and labour cost is Rs. 50/hour in both machines. Which of
these two machines is economical for making the bolt ?
UNIT-III: INTRODUCTION TO COST ESTIMATION
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1) What is meant by cost estimation?
• Cost estimating may be defined as the process of determining the probable cost
of the product before the start of the manufacture.
• Cost estimating, is performed by an experienced person called by various titles
including estimator, cost engineer, product cost estimator, purchase cost
analyst and manufacturing cost analyst.
2) State the importance of realistic estimates.
Effective project managers cultivate the courage and competency to push back
against arbitrary budgets and deadlines to negotiate realistic win-win cost and
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schedule estimates for their projects. This article explores how to negotiate
realistic estimates to set realistic expectations.
3) What are the objectives of cost estimation?
• To establish the selling price of a product for a quotation or contract, so as to
ensure reasonable profit to the company.
• To verify quotations submitted by vendors.
• To ascertain whether the proposed product can be manufactured and
marketed profitably.
• To take make or buy decision. i.e., to determine whether part
or assembly can be manufactured economically in the plant or
to be purchased from outside.
• To determine the most economical method process, or material for
manufacturing a product.
• To establish the standard of performance that may be used to control costs.
• To prepare production budget.
• To evaluate alternate designs of product.
• To initiate means of cost reduction in existing production facility by using
new materials, new methods of tooling and processing.
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4) Define costing.
Costing, also known as cost accounting, is the determination of an actual cost
of a component after adding different expenses incurred in various departments.
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5) What are the methods of costing?
• Job Costing or Order Costing
• Batch Costing
• Process Costing
• Departmental Costing
• Operating Cost Method
• Unit Cost Method
• Multiple Cost Method
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6) Distinguish between estimating and costing.
S. No
1
2
3
Estimating
It gives the probable cost of the
product before the start of its
manufacture.
Estimation require a highly
technical knowledge hence an
estimation is basically an engineer.
Estimating is done by
planning department.
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Costing
It gives the actual cost of the product
after
adding
different
expenses
incurred in various departments.
Costing requires the knowledge of
accounts and therefore costing is done
by accountants
Costing is done by accounting
department.
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7) What is meant by expenses or overheads?
• All the expenditures other than the direct material cost and direct labor
cost are known as expenses.
• The cost of indirect materials and indirect labor is also included in the
expenses.
• Expenses can be classified as: Direct expenses-Direct expenses are those
which can be charged directly to a particular job and are done for that
specific job only.
• Indirect expenses (overheads)-Indirect expenses are those which can be
charged indirectly to a particular job and are done for that specific job only.
8) List out the methods of allocating overheads.
• Allocation by cost proportion.
• Allocation by hourly rate.
• Allocation by unit rate.
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9) What are the causes of depreciation?
1. Depreciation due to physical conditions
a) Wear and tear
b) Physical decay c)
and neglect
2. Depreciation due to functional conditions
• a) Inadequacy
• b) Obsolescence
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Accident d) Poor maintenance
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10) Classify allowances in estimation.
• Relaxation allowance consists of: (i) Fatigue allowance, and (b)Personal
needs allowance
• Process allowance
• Interference allowance
• Contingency allowance
• Special allowance.
Part-B (13 Marks)
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1. Define the following terms: Set up time, Handling time, Machining time, and Tear
down time.
2. Explain the type of cost estimates used in estimating and list the various data
required to make a cost estimate.
3. List and discuss the different methods of cost estimating.
4. Explain the various methods of allocating overheads.
5. Explain the procedure followed for estimating the cost of an industrial product.
6. How will you estimate direct labour cost for mass production of an item?
7. Describe the various elements and components of cost.
8. What do you mean by a realistic estimate? Describe its importance in
production.
9. Name the various elements of cost. Explain each element in detail giving
suitable examples.
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1.
2.
3.
4.
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PART C
Explain in detail the procedure for estimating the cost of water supply
fitting in residential building.
Why costing is essential to industrial control?
Explain the terms prime cost, factory cost, total cost and selling price.
Show the relationship between various components of cost with the help of a block
diagram.
i. Allocation by percentage on direct labour cost.
ii. Allocation by percentage on direct material cost
UNIT-IV : PRODUCTION COST ESTIMATION
1. Define forging.
A process of working metal to a finished shape by hammering or pressing and is
primarily a "hot" operation. It is applied to the production of shapes either
impossible or too costly to make by other methods or needing properties not
obtainable by casting. Categories of forgings include Hammer, Press, Drop or
Stamping.
Final product is a result of the ram being powered into the dies
containing the workpiece.
An operation in which a metal shape is formed by forcing hot metal into
impressions formed in solid blocks of hardened alloy steel, the forging dies. The
dies are made in halves, one attached to the rising and falling block of the drop
forge and the other to the stationary anvil. Drop forgings are widely used in the
automotive industry for crankshafts, stub-axles, gears, etc.
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2. In what ways, press forging and upset forging are different?
Press forging works by slowly applying a continuous pressure or force, which
differs from the near-instantaneous impact of drop-hammer forging. The amount
of time the dies are in contact with the workpiece is measured in seconds (as
compared to the milliseconds of drop-hammer forges). The press forging operation
can be done either cold or hot.
Upset forging increases the diameter of the workpiece by compressing its length.
Based on number of pieces produced this is the most widely used forging process.
A few examples of common parts produced using the upset forging process are
engine valves, couplings, bolts, screws, and other fasteners.
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3. Define man hour and machine hour rate.
As the name indicates, this method is simply a combination of man-hour rate and
machine-hour rate methods. The man-hour rate method is suitable only where
work is done by hand, for example, in fitting and assembly shops etc. Similarly,
machine hour rate method is suitable where almost all the work is done by
machines. Thus, in this way, both the methods can be applied in one factory. This
method is combination of man-hour and machine-hour rate method of allocation.
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4. What is unit rate?
A rate is a ratio that is used to compare different kinds of quantities. A unit rate
describes how many units of the first type of quantity corresponds to one unit of
the second type of quantity. Some common unit rates are miles (or kilometers) per
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hour, cost per item, earnings per week, etc. In each case the first quantity is related
to 1 unit of the second quantity.
5. What are the various losses in forging?
While calculating the volume of material to be used for a component an allowance
is made for wastage of metal due to various factors. Various allowances to be taken
into account are discussed below:
a) Shear loss: The blank required for forging a component is cut from billets
or long bars. The material equal to the product of thickness of sawing blade
and cross- section of bar is lost for each cut. Similarly, if the small pieces left
at the end are not of full length, these also go as waste. Shear loss is generally
taken as 5 percent of net weight.
b) Tonghold loss: Drop forging operations are performed by holding the stock
at one end with the help of tongs. A small length, about 2.0 – 2.5 cm and
equal to diameter of stock is added to the stock for holding.
Tonghold loss = Area of X-section of bar × Length of tonghold
c) Scale loss: As the forging process is performed at very high temperature, the
Oxygen from air forms iron oxide by reacting with hot surface. This iron
oxide forms a thin film called scale, and falls off from surface at each stroke
of hammer. Scale loss is taken as 6 percent of net weight.
d) Flash loss: When dies are used for forging, some metal comes out of the die
at the parting line of the top and bottom halves of the die. This extra metal is
called flash. Flash is generally taken as 20 mm wide and 3 mm thick. The
circumference of component at parting line multiplied by cross-sectional
area of flash gives the volume of flash. The flash loss in weight is then
calculated by multiplying the volume of flash by density of the material.
e) Sprue loss: When the component is forged by holding the stock with tongs,
the tonghold and metal in the die are connected by a portion of metal called
the sprue or runner. This is cut off when product is completed. Sprue loss is
taken as 7 percent of net weight.
6. What are the types of welding?
• Tig welding
• Shielded metal arc welding also known as just plain arc welding or stick
welding
• Mig welding
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7. What is the pattern?
A pattern, from the French patron, is a type of theme of recurring events or objects,
sometimes referred to as elements of a set of objects. The elements of a pattern
repeat in a predictable manner. Patterns can be based on a template or model
which generates pattern elements, especially if the elements have enough in
common for the underlying pattern to be inferred, in which case the things are said
to exhibit the unique pattern.
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8. What is shrinkage allowance?
A shrinkage allowance for metal casting is something that must be figured into a
design from the very beginning. As the molten metal cools and solidifies it
will begin to contract. This means that although the molten metal completely
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filled up a mold, by the time the casting was cold, the casting is smaller than the
mold.
9. Differentiate leftward and rightward welding?
Leftward welding : In this method, welding is started from right hand side of the
joint and proceeds towards left. This method is used for welding plates upto 5 mm
thick. No edge preparation is required in case of the plates of thickness upto 3 mm.
Rightward welding : This method is adopted for welding thicker plates. Welding
proceeds from left to right. The flame is directed towards the deposited metal and
rate of cooling is very slow.
10.Give the formula for calculating cost of power in arc welding.
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Where,
V = Voltage; A = Current in Amperes ; t = Welding time in minutes ; E = Efficiency
of the welding machine = 0.6 for welding transformer, = 0.25 for welding
generator ; r = Ratio of operating time to connecting time taken by the operator
; C = Cost of electricity per kWh i.e., Unit.
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11. Name various sections in foundry shop.
• Pattern Making Section
• Sand mixing section
• Core making section
• Mould making section
• Melting section
• Fettling section
• Inspection section
Part-B (13
Marks)
1. An isometric view of a work piece is shown in figure. What will be the weight
of the material required to produce it. The density of material is 2.681 gm/cc.
Find also the material cost if its rate is Rs.13.60 per kg. (16)
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2. Estimate the weight of material required for manufacturing 220 pieces of shaft
as shown in figure. The shafts are made of mild steel which weighs 7.87 gm/cm3
and costs Rs.4.25 per kg. Also calculate the material cost for 220 such shafts. (16)
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3. A steel component shown in figure is to be drop forged in close impression dies.
Estimate the gross weight of the component. The various losses account for 26 %
of net weight. Take density as 7.7 gm/cc. (16)
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4. For manufacturing a ‘milling machine’, the expenditure is tabulated in table.
Find out (a) Prime cost, (b) Factory cost, (c) Total cost of production, (d) cost of
sales and (e) selling price.
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5. An open water tank of size 75 cm X 60 cm X 50 cm is made by gas welding from
a 4 mm thick metallic sheet. Estimate the time required for welding a tank. Neglect
other factors
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6. Estimate the material cost for welding 2 flat pieces of M.S. 15 X 16 1 cm size at an
angle of 90° by gas welding Neglect edge preparation cost and assume: Cost O2 = Rs.
10/m3 Cost of C2 H2 = Rs. 60/m2 Density of filler metal = 7 gm/cc Cost of filler metal
= Rs. 12/kg filler rod dia 5 mm filler rod required 4.5 m/m of welding assume O2
consumption = 0.7 cu.m/hr. C2H2 . Consumption = 0.5 cu.m/hr. Welding time = 30
min/m of welding.
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7. An engine flywheel is required to be cast according to drawing shown in
figure. (a) Estimate the net weight of the flywheel casting. (b) Estimate the selling
price of each wheel, given the following data:
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8. 20 numbers of gun metal bevel gear blank shown in figure are to be cast in the
factory from the planner supplied by the customer Estimate the selling price of
each piece from the following data. Cost of molten gun metal= Rs.9.20 per kg.
Scrap return value = Rs. 5 per kg. Process scrap = 10 % net weight of casting.
Administrative overheads=Rs.3.50 per kg
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9. 200 pieces of a component as shown in Fig. 2 are to be drop forged from 4 cm
diameter stock bar. Calculate the cost of manufacture, if (ii) Forging charges @
Rs. 0.01 per cm2 of surface area during operations.
All dimensions are in cm
1.
PART C
A factory has a capacity to produce 1000 shapers/annum. But at present ‘it is
working at its 70% capacity. The sales income at this level is Rs.52,50,000. The
fixed cost of the factory is Rs.20,00,000 and variable cost per piece is Rs.2500.
There is a proposal for mechanization but this will increase the fixed cost by
Rs.40,000 and will reduce the variable cost by Rs.500 per unit. Estimate:
a. Whether the proposal is economical? (8)
b. If a reduction in selling price by Rs.200 per unit make the factory to run
at 85 % of its full capacity, would this be a better proposal than the first
one. (8)
A C.I. factory employees 25 persons It consumes material worth Rs. 35,000
pays workers at the rate of Rs. 5 per hour and incurs total overheads of Rs.20,000
In a particular month (25 days) workers and an overtime of 150 hours and
were paid double than the normal rate. Find (i) the total cost, and (8), (ii) the man
hour rate of overheads. Assume 8 hours working days. (8)
Two workers complete 20 connecting rods, each weighing 3.5 kg by forging per
day.
They are paid at the rate of Rs.16 and Rs.14 per day respectively. If the material
cost is
Rs.7.25/kg and 60% of the direct labour is required to compensate for the factory
overheads, estimate the total cost of each rod.
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3.
4.
5.
6.
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UNIT 5: MACHINE TIME CALCULATION
PART -A
1. Define cutting speed. list the various factors affecting cutting speed.
Cutting speed is the speed at which the cutting edge of tool passes over the job and
it is usually expressed in meters per minute. The cutting speed depends on the
cutting tool material, the work piece material and the operation.
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2. What is machining time?
It is the time for which the machine works on the component, i.e. from the time
when the tool touches the work piece to when the tool leaves the component
after completion of operation. The machining time depends on the type and extent
of machining required, material being machined, speed, feed, depth of cut and
number of cuts required.
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3. Define tear down time.
It is the time taken to remove the tools, jigs and fixtures from the machine and to
clean the machine and tools after the operation has been done on the last
component of batch. The tear down time is usually small. The tear down time
occurs only once for a complete lot or batch taken for machining. Standard data are
available for tear down time for various machines.
4. What is tool approach and tool travel?
Approach is the distance a tool travels, from the time it touches the work piece until
it is cutting to full depth. Over travel is the distance the tool is fed while it is not
cutting. It is the distance over which the tool idles before it enters and after it leaves
the cut.
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5. Give formula for machining time for drilling?
Machining time for Drilling, T = L + Allowance / f x N
L = Length of drill travel = Length of hole + Allowance f = Feed per revolution
N = r.p.m. of drill
Allowance = 0.3 d for 118° drill point angle
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6. What are the typical data required for cutting time calculation in shaping?
The typical data required for cutting time calculation in shaping are Cutting to
return stroke ratio stroke length number of passes
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PART B & C
1. A mild steel bar 100 mm long and 38 mm in diameter is turned to 35 mm
dia. and was again turned to a diameter of 32 mm over a length of 40 mm as
shown in Fig. The bar was machined at both the ends to give a chamfer of 45⁰
X 5 mm after facing. Calculate the machining time. Assume cutting speed of
60 m/min and feed 0.4 mm/rev/ The depth of cut is not to exceed 3 mm in
any operation.
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2. A T-slot is to to be cut in C.I. slab as shown in figure. Estimate the machining time.
Take cutting speed 25 mm/min, feed is 0.25 mm/rev. Diameter of cutter for
channel milling is 80 mm.
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PANIMALAR ENGINEERING COLLEGE
Department of Mechanical Engineering
13
9
3. Estimate the machining time to drill four Ø8 mm 4 holes and one Ø 40 mm
central hole in the flange shown in figure. First Ø 20 mm hole is drilled and
then enlarge to Ø 40 mm holes. Take cutting speed 10 m/min, feed for 8
mm drill 0.1 mm/rev, for 20 mm drill feed is 0.2 mm/rev, and for Ø 40 mm
drill feed is 0.4 mm/rev.
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4. Consider the component as shown in figure. The component is to be made
from mild steel with Carbide tooling at a constant surface speed of 100 m/min on
a lathe with a maximum spindle speed of 1500 rev/min the machining allowance
is 2 mm. Determine (i) if the lathe is capable of turning the component at
the required surface speed; (ii) the total machining time for the component if the
lathe is capable.
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PANIMALAR ENGINEERING COLLEGE
Department of Mechanical Engineering
14
0
5. Find the machining time of the component shown in figure. If the material cost is
Rs.55/kg and the machine hour rate is Rs. 425/hr without OH, find the cost of
the component. Assume over head as 50% of machine hour rate and the set up time
is 3 min. Material is AISI 1040
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6. Calculate the machining time to mill a plate of thickness 24 mm and drill four 10
mm diameter holes and 50 mm diameter hole in the plate shown in fig. Assume
cutting speed and feed in the case of milling to be 75 m/min and 0.2 m/min
respectively. Cutting speed for drilling is 30 m/min and feed 0.15 mm/rev for 10
mm drill, 0.18 mm/rev for 25 mm drill and 0.3 mm/rev for 50 mm drill.
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7. Using the data in Table and the drawing in Fig. 1 (a), determine suitable speeds
(rev/min) and feeds (mm/rev) and the total machining time for all operations
listed. The raw material billet is Ø85 x 250 mm and the machining allowance to be
used is 5 mm. The surface cutting speeds and feed rate when machining brass
using HSS can be selected within the range 50 – 110 m/min and 0.15 – 8 mm/rev.
(Note: Select the maximum and minimum valves within the range for roughing and
finishing operations respectively)
Operation
Description
Face end
Turn ∅80 mm x 160 mm
Turn ∅70 mm x 100 mm
Turn ∅60 mm x 60mm
Parting off
Tooling
Description
HSS turning tool
HSS turning tool
HSS turning tool
HSS turning tool
HSS parting off tool
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Cutting conditions
Finish in one pass
One roughing cut, one finishing cut of 0.4 mm
One roughing cut, one finishing cut of 0.4 mm
One roughing cut, one finishing cut of 0.4 mm
Finish in one pass
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PANIMALAR ENGINEERING COLLEGE
Department of Mechanical Engineering
14
1
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8. (i) Find the time required to drill 4 holes in a CI flange each of 20 mm depth, if
the hole diameter is 20 mm. Assume cutting speed as 21.9 m/mine and feed
0.02 cm/rev.
(ii) A keyway has to be cut in a spindle whose dimensions are 46 cm length, 5 cm
diameter and 1 cm width. The cutter diameter is 13.25 cm. If the cutter
revolves at 120 rpm, what is the time required to cut a 1 m deep key way at a
feed of 0.05 cm/rev of cutter?
9. Estimate the machining time to turn a M.S bar of 3 cm diameter down to 2.5 cm
for a length of 10 cm in a single cut. Assume cutting speed = 30 m/min and feed =
0.4 mm/rev.
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