1
Acknowledgements
It gives us a great pleasure to present this project report as a part of final year
degree course in Production engineering.
We would like to express our profound gratitude and appreciation towards Prof.
C.N. Datye, Prof. (Miss) S.S. Mane for their constant guidance and help during the
entire course of the project.
We also wish to acknowledge the encouragement and suggestions provided by
Prof. S.S. Kuber, Prof. R.A.Waikar, Prof. P.K.Kale, on a timely basis during the course
of completion.
We would like to express our hearty and sincere gratitude towards Mr. Shripad
Khire (Manager-Process Planning, ThyssenKrupp Industries India) and Mr. Nitin
Gawhane (HR, ThyssenKrupp Industries India), for spending their valuable time with
us in helping us to complete this project.
We are also indebted to our HOD - Prof. Rajesh Dhake, and all other staff
members of Production department who have helped us directly / indirectly throughout
our endeavour.
Nilesh Sakhare
Neha Sahni
Pritam Solanki
2
Contents
Sr. No. Title Page no.
1. Company profile 5
2. Abstract 9
3. Problem Statement 9
4. Literature survey - Know-how of fixture and its related terminologies
4.1 Concept of locating 10
4.2 Principle of location 10
4.3 Common locating devices used 13
4.4 Clamping 13
4.5 Common clamping devices used 13
4.6 Base plate with grid pattern of holes 14
4.7 Modular fixtures 14
4.8 Standard fixture parts 14
5. Equipments involved
5.1 Specifications of the equipments 15
5.2 Objective/Need of fixture design 19
6. Design approach
6.1 An overview of the job (i.e. column) 20
6.2 Study of the job 22
6.3 Study of degrees of freedom of the job 27
6.4 Initial fixture design proposed 29
6.5 Importance of using base plate 31
6.6 Final fixture design accepted (Assembly drawing & Part drawings 33
7. Justification for the design
7.1 Calculations for face milling process involved 47
7.2 Calculations for drilling process involved 49
7.3 Calculations of allowable force/load that can be taken by elements 50
7.4 Calculated results for factor of safety
7.4.1 Assumptions made 53
7.4.2 Distribution of action of forces 53
7.4.3 Tabulated values of F.O.S for various elements 54
8. Cost analysis
8.1 Process sheet for base plate 1 (includes cost of machining) 64
8.2 Process sheet for base plate 2 (includes cost of machining) 68
8.3 Process sheet for tenon (includes cost of machining) 70
8.4 Process sheet for locating pin (includes cost of machining) 71
8.5 Cost of raw material 72
8.6 Process sheet for machining the columns (includes cost of machining) 73
9. Conclusion 74
10. Testing 75
11. Scope for improvement 75
10. References 76
3
List of figures
Fig. 1 - Company products 7
Fig. 2 - Degrees of freedom of an object in space 11
Fig. 3 - Six-point location system 12
Fig. 4a - Plano-miller machine 15
Fig. 4b - Skoda machine 16
Fig. 4c - HMT machine 17
Fig. 5 - Problem of bottlenecking of boiler drums - as seen on Plano-miller machine 19
Fig. 6a - Sugar Centrifugal machine 20
Fig. 6b - Columns of Sugar Centrifugal Machine 21
Fig. 7 - Left-hand and right-hand column 22
Fig. 8 - Various views of LH column 23
Fig. 9 - Various views of RH column 24
Fig. 10 - Dimensional drawing of the column 25
Fig. 11 - Analysis of degrees of freedom of the column 28
Fig. 12a - Sketch of initial fixture design 29
Fig. 12b - Sketch of initial fixture design 30
Fig. 13a - Use of base plate - as seen in 1st set-up 31
Fig. 13b - Use of base plate - as seen in 2nd
set-up 32
Fig. 14a - Assembly drawing for set-up 1 33
Fig. 14b - Part drawing for set-up 1
- Base plate 34
- Clamp and clamp rest 35
- Support block, screwjack and round plate 36
- Fabricated support block 37
- Bracket : Plates 1, 2 & 3 38
- Tenon 39
4
Fig. 15a - Assembly drawing for set-up 2 40
Fig. 15b - Part drawing for set-up 2
- Base plate 41
- Clamp and clamp rest 42
- Support block, screwjack and round plate 43
- Fabricated support block 44
- Locating pin 45
Fig. 16 - Assembly drawing of T-shaped fixture for lifting the column 46
Fig. 17 - Nomogram for calculation of power requirement 48 48
Fig. 18a - Pictorial sequence of machining of base plate 1 66
Fig. 18b - Pictorial sequence of machining of base plate 1 67
5
1. Company profile
6
A brief insight....
- Established in 1957, ThyssenKrupp Industries India Pvt. Ltd. (TKII) is a business unit of
ThyssenKrupp Foerdertechnik, a Group Company of ThyssenKrupp Technologies of the world
renowned ThyssenKrupp AG, Germany.
- Today, ThyssenKrupp is one of the world's largest industrial conglomerate with three main
lines of business activity: Steel, Capital Goods and Services, in all of which it occupies
leadership positions.
- Over the last five decades, TKII has grown to become one of the most trusted names in the
fields of Sugar Plant & Machinery, Open Cast Mining & Bulk Material Handing Systems,
Cement Plant & Machinery and Steam & Power Generation Plants.
7
Fig. 1 - Company products
Bulk material handling
system (conveyor)
Conveyor dryer
Stacker Five roller mill
8
Fig. 1 - Company products
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Bucket wheel excavator
Power plant Oil / Gas fired boiler
Batch centrifugal
9
2. Abstract
The main aim of the project is to shift the machining centre of the side arms (columns) of the
sugarcane machinery manufactured by Thyssenkrupp Industries India Ltd. Previously, these columns
used to be manufactured on Skoda machine, which otherwise could have been used to handle much
larger workpieces. The set-up time required to machine the columns simultaneously on Skoda is too
high. Presently, this scheduled procedure of production causes the problem of bottlenecking on Plano-
miller machine. Moreover, the Skoda machine costs around Rs. 2000/hr for actual machining of the
columns, as compared to Rs. 1200/hr that can be possibly incurred on the proposed HMT machine.
Hence, the shifting pattern for the given workpieceto be followed is :
The suggested solution of the officials is the shifting of machining of columns to smaller
machining centres like HMT so that bigger machines like Skoda and Plano-miller could be ultimately
used for larger jobs . Also, since HMT machine has two pallets, while one column is being machined
(say left-handed), offline setting of the other column (say right handed) can be done. This reduces the
overall setting time by a significant amount.
The working outline includes designing of two different fixture set-ups for the desired
machining operations to be done, as per the given geometry of the job.
3. Problem statement
Design of fixture for machining (with reference to the columns of Sugar Centrifugal
Machines in ThyssenKrupp Industries India)
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Plano-miller Skoda HMT
10
4. Know-how of fixture and its related terminologies
Fixture [4][5] is a special purpose tool which is used to facilitate production (machining,
assembling and inspection operations) when workpieces are to be produced on a mass scale. Some of
the manifold uses of designing and setting-up fixtures include :
1. To increase the production.
2. To provide for interchangeability.
3. To enable heavy and complex-shaped parts to be machined by being rigidly held to a machine.
4. Their use improves the safety at work, thereby lowering the rate of accidents.
Hence,
“ A fixture is a work holding device which only holds and positions the work, but does not in itself
guide, locate or position the cutting tool. “ The setting of the tool is done by machine adjustment. A
fixture is bolted or clamped to the machine table.
4.1 Concept of locating....
The question of properly locating, supporting and clamping the work is important since the
overall accuracy is dependent primarily on the accuracy with which the w/p is consistently located
within the fixture. There must be no movement of the work during machining. Locating refers to the
establishment of a proper relationship between the workpiece and the fixture so that as many
degrees of freedom (out of 12) should get restricted as possible.
4.2 Principle of location....
In a state of freedom, any workpiece (assuming it has true and flat faces) may move in either of
the two opposed directions along three mutually perpendicular axes XX, YY and ZZ axes. These six
movements are called “movements of translation”. Also, the w/p can rotate in either of two opposed
directions around each axis, clockwise and anticlockwise. These six movements are called “rotational
movements”. The sum of these two types of movements gives the twelve degrees of freedom of a w/p in
space. To confine the workpiece accurately and positively in another fixed body (fixture), the
movement of the workpiece in any of the twelve degrees of freedom must be restricted.
11
Usually, six locating pins, three in the base of the fixed body, two in a vertical plane and one in
another vertical plane, the three planes being perpendicular to one another, restrict nine degrees of
freedom. In case three more pins are used for the remaining three degrees of freedom, then that would
make loading and unloading of w/p into the fixture impossible. Hence, the remaining three degrees of
freedom may be arrested by means of a clamping device. This method of locating a w/p is popularly
called “3-2-1” principle or “six point location” principle. [5]
Fig. 2 - Degrees of freedom of an object in space
12
Fig. 3 - Six-point location system
13
4.3 Common locating devices used....
Pins are stops which are inserted in the body of fixture, against which the workpiece is pushed
to establish the desired relationship between the workpiece and the fixture. Pins of various designs and
made of hardened steel are the most common locating devices used. Depending upon the relation
between the workpiece and pin, the pins may be classified as [5]:
1. Locating pins
a. Conical locating pins
b. Cylindrical locating pins
2. Support pins
a. Adjustable type
b. Fixed type
3. Jack pins
Other locating devices include V-type locator, diamond pin locator, bushes, etc.
4.4Clamping....
If the workpiece cannot be restrained by the locating elements, it becomes necessary to clamp
the w/p in the fixture body. The purpose of clamping is to exert a pressure to press a w/p against the
locating surfaces and hold it there in opposition to the cutting forces i.e.to secure a reliable (positive)
contact of the work with locating elements and prevent the work in the fixture from displacement
and vibration in machining[5].The most common example of a clamp is the bench vise, where the
movable jaw of the vise exerts force on the w/p thereby holding it in the correct position of location in
the fixed jaw of the vise.
4.5Common clamping devices used....
Some of the common clamping devices used in practice [5] are :
1. Clamping screws
2. Hook bolt clamp
3. Lever type clamps
a. Bridge clamps
b. Heel clamps
c. Swinging strap (latch) clamps
d. Hinged clamps
4. Quick acting clamps
a. C-clamps
14
b. Quick acting nut
c. Cam-operated clamp
** No clamping devices are used if a very heavy stable job is to be machined, whose weight is very
great compared to the forces developed in the cutting process, if these forces are in a direction that
cannot disturb the setting of the job.
** Clamping devices are also unnecessary if the job is deprived of all of its degrees of freedom when it
is loaded into a fixture.
4.6Base plate with grid pattern of holes....
A base plate (square or rectangular) with a grid pattern of holes [5] is especially suitable as a
work-holding device for N/C and CNC machine tools. The holes are usually on 25mm centres. Every
other hole is tapped to hold down studs or screws. The remaining holes are jig-bored to 0.005mm
accuracy, and these holes hold dowel pins. The dowel pins act as locators and the studs and screws are
used for clamping the w/p on the plate. The grid plate, in turn, is bolted directly on the machine table.
This system can be used for an infinite varieties of w/p.
The bottom-left hole is taken as the zero reference point. With this, the grid pattern and hence
the w/p will be placed in the first quadrant. All the dimensions measured from the reference point will
be positive in magnitude. The N/C machine tool is set-up by bringing the machine spindle directly over
the reference hole with the help of a dial indicator mounted on the spindle. The w/p is then located and
held on the grid plate in reference to the set-up point.
** One major drawback of grid plate is that the chips get accumulated in the holes. However, this can
be avoided by keeping all the unused holes plugged.
4.7Modular fixtures....
These fixtures are commonly used on N/C and CNC machining centres [5]. The fixtures
comprise of modular components based on the grid principle (A module is an interchangeable “plug in”
item that may be combined with other interchangeable items to form a complete unit i.e. a modular
fixture is built up on the building block principle). The w/p locators are located approximately on the
grid pattern and then the w/p is precision-machined under tape control. Dowel pins are not used.
4.8 Standard fixture parts....
The basic purpose of standardization [5] of any manufactured items is to ensure
interchangeability (which is the basis of mass production) and facilitate the manufacture of parts. It also
facilitates maintenance and repair. When designing and manufacturing fixtures, maximum use should
be made of standard, readily purchasable (or available in store) component parts. This will reduce the
cost of design and manufacturing considerably.
The standardized component parts for fixtures include : Washers, various types of screws, studs
and nuts, T-bolt and T-nut, toggles, cam and wedge etc.
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15
5.Equipments involved
5.1 Specifications of the equipments….
Skoda : X6000, Y3500, Z1600+400
Spindle – 200 (ISO - 60)
Plano-miller : X6000, Y2000, Z2000
Spindle ISO 50
On table : Max. wt. = 35000kg
HMT (Twin Pallet) : Pallet 1000*1000
X1750, Y1300, Z1000
ATC 60 tools
Spindle ISO 5
Fig. 4a - Plano-miller machine
16
Fig. 4b – Skoda machine
17
Fig. 4c – HMT machine
18
Bottlenecking
19
Fig. 5 – Problem of bottlenecking of boiler drums --- as seen on Plano-miller machine
5.2 Objectives….
- To avoid bottlenecking of Plano-miller machine (as shown in Fig. 5)
- To eliminate the necessity of using a costlier work-center (Skoda machine), by designing a suitable
fixture which can be accommodated on the proposed HMT machine .
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20
6.Design approach
6.1An overview of the job involved....
Fig. 6a – Sugar Centrifugal Machine
21
Fig. 6b - Columns of Sugar Centrifugal Machine
Finished
left-
hand
column
Fabricat
ed left-
hand
column
22
6.2 Study of the job....
The given component is not a regular shaped workpiece. It is an eccentric component. Also,
when we look at the specifications of HMT machine, it is quite obvious that both the columns can’t be
machined simultaneously. The geometry of the column (i.e. the need to machine faces which are
perpendicular and/or parallel to each other) and the limitations of the machine space utilisation call for
designing two different set-ups of fixture to hold the column while machining.
Fig. 7 – Left-hand and right-hand columns
Left-hand
column
Right-hand
column
23
Fig. 8 – Various views of LH column
24
Fig. 9 – Various views of RH column
25
Fig. 10 – Dimensional drawing of the column
26
As per the functional requirement, six faces of the LH column and three faces of the RH
column are to be machined. Since these faces are parallel and/or perpendicular to each other, they are to
be machined in two different orientations. Each of the face requires milling and drilling operations. The
requirements are as shown below :
Face number Operation required
*1 Milling Tapping three M20 holes
2 Milling
Drilling two Ø27 holes, two Ø50.2 holes
Tapping two M24 holes
3 Milling Drilling two M20 holes
4 Milling Tapping two M20 holes
*5 Milling Tapping two M20 holes
*6 Milling Drilling four M10 holes
*Additional holes to be drilled and tapped - ½” BSP hole & 1½” BSP hole
* indicates those operations are to be performed on LH column only. The rest are to be
performed on both
“Thus, LH column requires total 6 milling operations, 21 drilled holes and 11 tapped holes
RH column requires total 3 milling operations, 10 drilling holes and 4 tapped holes “
27
6.3 Study of degrees of freedom of the column....
As mentioned in the previous title, the given component requires two different fixture set-ups for
holding. So the basic approach to design started with the analysis of degrees of freedom [5] of the
column in both the orientations possible.
1st set-up :
Element for restricting degree Degree of freedom restricted
of freedom
Base plate YY↓
Screwjack XX CL/ACL , ZZ → , YY ←
Clamp YY ↑ , XX ↕ , YY CL/ACL (also
restricted due to the weight of the
column) , ZZ CL/ACL
L-shaped support ZZ ←
2nd
set-up :
Element for restricting degree Degree of freedom restricted
of freedom
Base plate YY ↓
Screwjack XX CL/ACL , ZZ →
Locating pin YY ↓ , YY CL/ACL , ZZ ↔ , XX ↕
Clamp YY ↑, YY CL/ACL , ZZ CL/ACL
**(where ↕ indicates linear movement, and CL/ACL indicate rotational movements in both the
directions as applicable to the respective axes)
28
Fig. 11 – Analysis of degrees of freedom of the column[2]
29
6.4 Initial fixture design proposed (not to scale)....
Fig. 12a - Sketch of initial design proposed
30
Fig. 12b - Sketch of initial design proposed
31
6.5 Importance of using base plate....
While designing a fixture, the pre-requisite condition that is to be considered is that “both the
columns should be machined together”. This is to maintain the centre distance and height of the
columns from the point of view of positioning the central shaft of the sugarcane machinery set-up.
However, because of the geometry of the column and limitations of the specifications of the machine,
two different fixture set-ups have to be designed. In order to comply with the condition put forth, base
plates of known dimensions are being used. Every time before any process is started on the required
face, respective dimensions (height and centre distance) will be measured with respect to the known
dimensions of the base plate. Also, the dimensions will be measured post process in succession. Then,
as per the tolerances set, the dimensions are checked and kept within the limits in every pass.
One more use of the base plate is for quick-setting of the column in the second set-up. The base
plates for both the set-ups are being provided with holes for tenons and allen screws. Tenons and allen
screws serve the purpose of locating (fixing) the base plate with respect to the modular fixture. In case
of second set-up, additional holes (for locating pins and allen screws) are being drilled to quickly
set/position the column.
Fig. 13a –Necessity of base plate – as seen in set-up 1
32
Fig. 13b – Necessity of base plate – as seen in 2nd
set-up
33
6.6 Final fixture design accepted....
Fig. 14a – Assembly drawing for set-up 1
34
Fig. 14b – Part drawing of set-up 1 : Base plate
35
Fig. 14b – Part drawing of set-up 1 : Clamp and clamp rest
36
Fig. 14b – Part drawing of set-up 1 : Support block,screwjack and round plate
37
Fig. 14b – Part drawing of set-up 1 : Fabricated support block
38
Fig. 14b – Part drawing of set-up 1 : Bracket – Plates 1, 2 and 3
39
Fig. 14b – Part drawing of set-up 1 : Tenon
40
Fig. 15a – Assembly drawing for set-up 2
41
Fig. 15b – Part drawing of set-up 2 : Base plate
42
Fig. 15b – Part drawing of set-up 2 : Clamp and clamp rest
43
Fig. 15b – Part drawing of set-up 2 : Support block, screwjack and round plate
44
Fig. 15b – Part drawing of set-up 2 : Fabricated support block
45
Fig. 15b – Part drawing of set-up 2 : Locating pin
46
Fig. 16 – Assembly drawing of T-shaped fixture for lifting the column
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47
7. Justification for the design
7.1 Calculations for face milling process involved....
Cutting forces generated
Component
Part
Power
required
(kW)
Px
(kgf)
Py
(kgf)
*Pz
(kgf)
Part no. 2
(rough mill)
21.6 403.92 257.04 734.4
Part no. 2
(finish mill)
16.9 316.03 201.11 574.6
Part no. 3 17.6 329.12 209.44 598.4
Part no. 3 12 224.4 142.8 408
Part no. 4 19.5 364.65 232.05 663
Part no. 4 14.3 267.41 170.19 486.2
Part no. 1 8.5 158.95 101.15 289
Part no. 1 6.05 113.135 71.995 205.7
Part no. 5 9.35 157.08 111.265 317.9
Part no. 5 8.4 157.08 99.46 285.6
1. Actual power required (considering correction factors) [7]
N’ = N*K1*K2*K3
where N = Power obtained from nomogram,
K1 = Correction factor for material,
K2 = Correction factor for feed and cutter location w.r.t workpiece
width
K3 = Correction factor for negative geometry
48
2. Tangential force Pz = (6120*N’)/v kgf
3. Axial force Px = 0.55*Pzkgf
4. Radial force Py = 0.35*Pzkgf
Sample calculation :
Consider rough milling of bottom plate part 2.
Power obtained from nomogram(for cutter dia. = 160mm, v = 180m/min, feed = 400mm/min., d =
2mm, width of workpiece = 250mm) is 18kW (approx.)
For the given face, K1 = 1, K2 = 1, K3 = 1.2
Therefore, actual power required (N)= 18*1*1*1.2 = 21.6 kW
Pz = (6120*21.6)/180 = 734.4 kgf
Px = 0.55*734.4 = 403.92 kgf
Py = 0.35*734.4 = 257.04 kgf
Fig. 17 – Nomogram for calculation of power requirement
49
7.2 Calculations for drilling process involved....
Cutting forces generated
Drill size Power
Required (kW)
Px
(kgf)
Pz
(kgf)
U drill Ø27 1.1745 65.772 55.355
U drill Ø22 1.329 74.443 64.096
U drill Ø35 0.5709 31.9725 15.577
U drill Ø49 0.79931 44.761 15.5772
Drill Ø17.5 0.1 67.3105 57.533
Chamfer Ø20 0.32625 36.54 31.154
Chamfer Ø22 0.3586 40.194 31.1545
Drill Ø12.5 0.5709 31.9725 31.1545
Drill Ø19 0.6198 34.713 31.1545
Drill Ø35 1.14187 63.945 62.309
Drill Ø50 1.61325 91.35 62.309
1. Machine power in kW for U drill [10] (kW)
P = (Vc*f*D*Kc)/(1000*60*4*ƞ)
where f = feed rate in mm/rev.
Kc= specific cutting force in N/mm2
D = diameter in mm
Vc = cutting speed in m/min.
ƞ = machine output (0.7 to 0.85)
50
2. Feed force Ff=Px = 0.7*(D/2)*f*Kc (N)
3. Tangential force Pz = ((P*1000*60)/((2∏n)*(D/2))*1000 (kgf)
** The cutting forces generated during reaming operation are almost negligible. Hence they are
not being considered for the calculation purpose.
Sample calculation :
For drilling a hole of dia. 27mm on part no. 2, the cutting parameters are Vc= 120 m/min. , f = 60/1500
= 0.04 mm/rev. , D = 27mm, Kc= 1740
N/mm2, ƞ = 0.8 (say). Then,
P = (120*0.04*27*1740) / (1000*60*4*0.8) = 1.1745 kW
Px = 0.7*(27/2)*0.04*1740 = 657.72 N = 65.772 kgf
Pz = ((1.1745*1000*60) / ( 2∏* 1500)*(27/2))*1000 = 553.85 N = 55.385 kgf
7.3 Calculations of allowable force / load that can be taken by various elements….
Values of allowable stresses [1] (for varying load)that are involved in the design are :
For M.S. Tension : 3.5 kgf/mm2 , Shear = 2.2 kgf/mm
2 , Compression = 10.5 kgf/mm
2 , Bending =
3.5 kgf/mm2 , Bearing pressure = 2.9kgf/mm
2
For EN .8 Shear = 3.7 kgf/mm2
For EN .24 Shear = 8.7 kgf/mm2
1. Clamp
Effective area = (70-28)*30 = 1260mm2
Allowable tensile force = 1260*3.5 = 4410 kgf
Allowable shear force = 1260*2.2 = 2772 kgf
µ = 0.1 to 0.15 for a pair of M.S.
Hence, allowable frictional force = 0.15*2772 = 415.8 kgf
2. Stud (M24*375L)
Pitch = 2mm Core dia. = 24-2 = 22mm
51
Area of stud = (3.14/4)*222 = 380.1327mm
2
Allowable shear force = 2.2*380.1327 = 836.29 kgf
3. Bolt (M24*75L)
Pitch = 2mm Core dia. = 24-2 = 22mm
Area of stud = (3.14/4)*222 = 380.1327mm
2
Allowable shear force = 2.2*380.1327 = 836.29 kgf
4. Allen screw (M20*50L)
Area = (3.14/4)*17.52 = 240.5281 mm
2
Allowable tensile force = 3.5*240.5281 = 841.848 kgf
Allowable shear force = 2.2*240.5281 = 529.16 kgf
5. Allen screw (M10*20L)
Area = (3.14/4)*8.52 = 56.745mm
2
Allowable compressive force = 10.5*56.745 = 595.8225kgf
6. Lock nut M24
Area = (3.14/4)*242 = 452.3893mm
2
7. Lock nut M30
Area = (3.14/4)*302 = 706.8583 kgf
Allowable shear force = 2.2*706.8583 = 1555.088 kgf
8. Support block
Area = (3.14/4)*(602-40
2) = 1570.796 mm
2
Allowable compressive force = 3.5*1570.796 = 5497.786 kgf
52
9. Round plate
Effective area = (3.14/4)*(602-11
2) = 2732.4002 kgf
Allowable shear force = 2.2*2732.4002 = 6011.28 kgf
10. Locating pin
Area = (3.14/4)*302 = 706.858 mm
2
Allowable shear force = 3.7*706.858 = 2615.3746 kgf
11. Tenon
Area = (3.14/4)*(162-6
2) = 172.7875 mm
2
Allowable shear force = 8.7*172.7875 = 1503.25 kgf
12. Bracket for support
Plate 1 : Area = 16*75=1200mm2
Allowable shear force = 2.2*1200 = 2640 kgf
Plate 2 : Area = 16*(75-(10-1.5)) = 1064 mm2
Allowable bending force = 3.5*1064 = 3724 kgf
Plate 3 : Area = 16*87.7 = 1403.2 mm2
Allowable bending force = 3.5*1403.2 = 4911.2 kgf
Weld : Throat thickness = 16cos26.5 = 14.32 mm
Area = 14.32*87.7 = 1254.864 mm2
Allowable shear force = 2.2*1254.864 = 2762.9008 kgf
13. Screw jack
Height of lock nut = 0.8*30 = 24 mm
Pitch = 3.5 mm
Hence, no. of threads in engagement = 24/3.5 = 6.857 i.e. 7
53
a.Bearing area = (3.14/4)*[(30/cos14.5)2 – (26.5/cos14.5)
2] = 165.7002 mm
2
Allowable bearing force = 2.9*165.7002*7 = 3363.714 kgf
b. Shear area for screw = 3.14*dc*t*n = 3.14*26.5*(3.5/2)*7 = 1019.8395 mm2
Shear area for nut = 3.14*do*t*n = 3.14*30*(3.5/2)*7 = 1154.5353 mm2
Allowable shear force = 2.2*1019.8395 = 2243.646 kgf
7.4 Calculated results of Factor of safety….
7.4.1 Assumptions :
1. The allowable forces are being calculated for varying load condition
2. The cumulative forces acting on the set-up are not being distributed for calculation purpose. The
entire force is being assumed to act on all the individual elements
3. The weight of the column was not distributed while making the calculations.
4. The entire screwjack type arrangement only acts as a support to accommodate the geometry of the
job, and majorly to take care of the vibrations produced during machining. Still, for calculation
purpose, it is considered to be a load bearing element to evaluate its strength
**Points 2 and 3 justify why the factor of safety obtained in the calculations is pretty high.
7.4.2 Distribution of action of forces on various elements….
1. Due to milling, three forces Px,Pyand Pzact on the column. Tangential component Pzprovides the
necessary torque for rotation. This component may tend to lift the column about an axis that is parallel
to the axis of the cutter. This lifting is prevented by the clamps, such that, in the first set-up, two clamps
are in tension and the remaining two are in compression, alternately. In the second set-up, one is in
tension and the other is in compression, alternately.
2. Px acts as a shearing force. Hence, this shearing is resisted by bolts, allenscrews,tenons, locating pins,
and frictional component of clamp.
3. Py tends to rotate the column about an axis perpendicular to the axis of the cutter. This rotation is
resisted by bolts, allen screws, tenons, and locating pins.
4. The screwjack type arrangement resists Pz component of milling and drilling operations involved.
5. During drilling, Px component will provide the shearing force. This will be resisted by bolts, allen
screws, tenons, and locating pins .
54
7.4.3 The tabulated values of the factor of safety of various elements used
Part 3
Operation Operation
Rough Milling Drilling
Px
(kgf)
Py (kgf) Pz (kgf) Px (kgf) Py
(kgf)
Pz (kgf)
329.12 209.44 598.4 67.3105 - 51.533
Weight of job 400 kgf
Wt. of base plate 318.396 kgf
Fixture elements Factor of safety
1. Clamp 1.26 - 7.36 6.177 - -
2. Bolt 2.54 3.99 - 12.42 - -
3. Clamp rest 3.02 4.75 - 14.78 - -
4. Lock nut M24 3.02 4.75 - 14.78 - -
5. Stud 2.54 3.99 - 12.42 - -
6. Bracket
Plate 1 - - 3.146 - - 9.033
Plate 2 - - 4.057 - - 10
Plate 3 - - 5.35 - - 13.2
Weld section - - 3.01 - - 7.5
7. Round plate - - 6.02 - - 13.31
8. Screwjack - - 2.25 - - 4.97
55
3.37 7.44
9. Support block - - 5.506 - - 12.17
10. Allen screw
(M20 * 50 L)
- - 1.686 - - 3.73
11. Allen screw
(M20 * 50 L)
1.45 1.736 - 2.265 - -
12. Allen screw
(M10 * 20 L)
- - 1.193 - - 2.64
13. Tenon 1.435 1.62 - 1.91 - -
14. Lock nut M30 4.72 7.42 - 23.103 - -
----------------------------------------------------------------------------------------------------------------------
Part 2
Operation Operation
Rough Milling Drilling
Px (kgf) Py (kgf) Pz (kgf) Px (kgf)
Py
(kgf) Pz (kgf)
403.92 257.04 734.4 74.433 - 64.096
Weight of job 400 kgf
Wt. of base plate 318.396 kgf
Fixture elements Factor of safety
1. Clamp 1.029 - 6.004 5.586 - -
56
2. Bolt 2.07 3.25 - 11.23 - -
3. Clamp rest 2.46 3.87 - 13.37 - -
4. Lock nut M24 2.46 3.87 - 13.27 - -
5. Stud 2.07 3.25 - 11.23 - -
6. Bracket
Plate 1 - - 2.7 - - 8.66
Plate 2 - - 3.53 - - 9.7
Plate 3 - - 4.66 - - 12.8
Weld section - - 2.62 - - 7.2
7. Round plate - - 5.3 - - 12.9
8. Screwjack - - 1.97
2.965 - -
4.83
7.25
9. Support block - - 4.846 - - 11.8
10. Allen screw
(M20 * 50 L) - - 1.48 - - 3.627
11. Allen screw
(M20 * 50 L) 1.316 2.96 - 2.23 - -
12. Allen screw
(M10 * 20 L) - - 1.05 - - 2.567
13. Tenon 1.339 1.54 - 1.896 - -
14. Lock nut M30 3.849 6.04 - 20.8 - -
57
Part 4
Operation Operation
Rough Milling Drilling
Px (kgf) Py (kgf) Pz (kgf) Px (kgf) Py
(kgf)
Pz (kgf)
364.65 232.05 663 67.3105 - 51.533
Weight of job 400 kgf
Wt. of base plate 172.7kgf
Fixture elements Factor of safety
1. Clamp 1.14 - 6.65 6.177 - -
2. Bolt 2.29 3.60 - 12.42 - -
3. Clamp rest 2.729 4.288 - 14.78 - -
4. Lock nut M24 2.72 4.28 - 14.78 - -
5. Stud 2.29 3.60 - 12.42 - -
6. Bracket
Plate 1 - - 2.92 - - 9.03
Plate 2 - - 3.79 - - 10
Plate 3 - - 4.99 - - 13.2
Weld section - - 2.81 - - 7.44
7. Round plate - - 5.655 - - 13.3
8. Screwjack - - 2.11
3.16
- - 4.96
7.449
58
9. Support block - - 5.17 - - 12.17
10. Allen screw
(M20 * 50 L)
- - 1.583 - - 3.728
11. Allen screw
(M20 * 50 L)
1.384 1.674 - 2.264 - -
12. Allen screw
(M10 * 20 L)
- - 1.12 - - 2.639
13. Tenon 1.6037 1.867 - 2.348 - -
14. Lock nut M30 4.264 6.70 - 23.1 - -
15. Locating pin 3.42 4.137 - 5.596 - -
16. Allen screw
(M24*375L)
1.784 2.078 - 2.741 - -
----------------------------------------------------------------------------------------------------------------------
Part 1
Operation Operation
Rough Milling Drilling
Px (kgf) Py (kgf) Pz (kgf) Px (kgf) Py
(kgf)
Pz (kgf)
158.95 101.15 289 67.3105 - 51.533
Weight of job 400 kgf
Wt. of base plate 172.7kgf
Fixture elements Factor of safety
59
1. Clamp 2.61 - 15.25 6.177 - -
2. Bolt 5.26 8.26 - 12.42 - -
3. Clamp rest 6.26 9.83 - 14.78 - -
4. Lock nut M24 6.26 9.8 - 14.78 - -
5. Stud 5.26 8.26 - 12.42 - -
6. Bracket
Plate 1 - - 4.983 - - 9.032
Plate 2 - - 6.12 - - 10.03
Plate 3 - - 8.071 - - 13.2
Weld section - - 4.54 - - 7.447
7. Round plate - - 8.72 - - 13.31
8. Screwjack - - 3.256
4.882
- - 4.968
7.449
9. Support block - - 7.979 - - 12.17
10. Allen screw
(M20 * 50 L)
- - 2.44 - - 3.728
11. Allen screw
(M20 * 50 L)
1.893 2.117 - 2.264 - -
12. Allen screw
(M10 * 20 L)
- - 1.729 - - 2.639
13. Tenon 2.054 2.23 - 2.348 - -
14. Lock nut M30 9.78 15.37 - 23.1 - -
60
15. Locating pin 4.67 5.218 - 5.596 - -
16. Allen acrew
(M24*375L)
2.286 2.482 - 2.613 - -
----------------------------------------------------------------------------------------------------------------------
Part 5
Operation Operation
Rough Milling Drilling
Px (kgf) Py (kgf) Pz (kgf) Px (kgf) Py
(kgf)
Pz (kgf)
174.85 111.27 317.9 91.35 - 62.309
Weight of job 400 kgf
Wt. of base plate 172.7kgf
Fixture elements Factor of safety
1. Clamp 2.37 - 13.87 4.55 - -
2. Bolt 4.78 7.51 - 9.15 - -
3. Clamp rest 5.69 8.94 - 10.89 - -
4. Lock nut M24 5.69 8.9 - 10.8 - -
5. Stud 4.78 7.51 - 9.15 - -
6. Bracket
Plate 1 - - 4.72 - - 8.71
Plate 2 - - 5.842 - - 9.75
61
Plate 3 - - 7.70 - - 12.86
Weld section - - 4.334 - - 7.237
7. Round plate - - 8.373 - - 13.00
8. Screwjack - - 3.125
4.685
- - 4.853
7.275
9. Support block - - 7.658 - - 11.89
10. Allen screw
(M20 * 50 L)
- - 2.345 - - 3.64
11. Allen screw
(M20 * 50 L)
1.841 2.069 - 2.153 - -
12. Allen screw
(M10 * 20 L)
- - 1.659 - - 2.577
13. Tenon 2.010 2.197 - 2.263 - -
14. Lock nut M30 8.89 13.9 - 17.02 - -
15. Locating pin 4.54 5.115 - 5.323 - -
16. Allen acrew
(M24*375L)
2.237 2.445 - 2.518 - -
----------------------------------------------------------------------------------------------------------------------
Part 6
Operation Operation
Rough Milling Drilling
62
Px (kgf) Py (kgf) Pz (kgf) Px (kgf) Py
(kgf)
Pz (kgf)
19.55 43.01 78.2 34.51 - 38.46
Weight of job 400 kgf
Wt. of base plate 172.7kgf
Fixture elements Factor of safety
1. Clamp 21.2 - 56.3 12.04 - -
2. Bolt 42.7 19.44 - 24.2 - -
3. Clamp rest 50.9 23.1 - 28.8 - -
4. Lock nut M24 50.9 23.1 - 28.8 - -
5. Stud 42.7 19.44 - 24.233 - -
6. Bracket
Plate 1 - - 8.277 - - 9.45
Plate 2 - - 9.36 - - 10.4
Plate 3 - - 12.35 - - 13.72
Weld section - - 6.948 - - 7.719
7. Round plate - - 12.57 - - 13.7
8. Screwjack - - 4.69
7.034
- - 5.117
7.67
9. Support block - - 11.49 - - 12.53
10. Allen screw
(M20 * 50 L)
- - 3.52 - - 3.84
63
11. Allen screw
(M20 * 50 L)
2.522 2.388 - 2.435 - -
12. Allen screw
(M10 * 20 L)
- - 2.49 - - 2.717
13. Tenon 2.538 2.441 - 2.4756 - -
14. Lock nut M30 39.77 36.1 - 45.06 - -
15. Locating pin 6.233 5.90 - 6.019 - -
16. Allen acrew
(M24*375L)
2.824 2.716 - 2.754 - -
Sample calculation :
Factor of safety = Maximum allowable force / Working force
1. Clamp
F.O.S.xm = 415.8/329.12 = 1.26
F.O.S.xd = 415.8/67.3105 = 6.177
F.O.S.zm = 4410/598.4 = 7.36
2.Bolt
F.O.S.xm= 836.29/329.12 = 2.54
F.O.S.ym = 836.29/209.44 = 3.99
F.O.S.xd = 836.29/67.3105 = 12.42
----------------------------------------------------------------------------------------------------------------------
64
8. Cost Analysis
8.1 Process sheet for base plate 1
Sr. No.
Operation sequence Cutting parameters [3] [6] [7] Machining time
(minutes)
1. Face mill surface F by 2mm
(n=1) v=100, sz=0.30, d=2, z=16, Ø=160,
L=1311.44 t = 1.37 *2
Repeat this for surface E
2. Face mill surface C by 2mm
(n=1) v=100, sz=0.30, d=2, z=16, Ø=160,
L=607.44 t = 0.636 *2
Repeat this for surface D
3. Face mill surface A by 2mm
(n=4) v=100, sz=0.30, d=2, z=16, Ø=160,
L=1354.8442 t = 1.289 *8
Repeat this three more times
Face mill surface B in a similar manner
4. Drill Ø21 holes
(n=8) v=33, f=0.30, Ø=21, L=68.49 t = 0.45 *8
Drill 8 holes in all
Ream Ø22 holes
(n=8) v=20, f=0.6, Ø=22, L=69.18 t = 0.39 *8
Ream 8 holes in all
5. Bore to Ø32*35mm
(n=8)
v=31, f=0.25, d=2.5, L=35, Ø=22 v=31, f=0.25, d=2.3, L=35, Ø=27
v=33, f=0.125, d=0.2, L=35, Ø=31.6
t = 0.32 *8 t = 0.38 *8 t = 0.84 *8
Bore 8 holes in all
6. Drill Ø16 holes
(n=4) v=30, f=0.25, Ø=15, L=65.04 t = 0.408 *4
Ream Ø16 holes
(n=4) v=20, f=0.3, Ø=16, L=54 t = 0.45 *4
Drill and ream 4 holes in all
7. Tap M24 holes
65
Drill Ø21 holes v=33, f=0.30, Ø=21, L=68.49 t = 0.45 *4
Tap M24*3 holes v=12, f=0.4, Ø=24, L=54 t = 0.84 *4
Drill and tap 4 holes in all
8. Finish mill all surfaces
Surfaces E and F
(n=2) v=135, sz =0.4, d=1, Ø=160, z=16,
L=1306.69 t = 0.76 *2
Surfaces C and D
(n=2) v=135, sz =0.4, d=1, Ø=160, z=16,
L=606.69 t = 0.35 *2
Surfaces A and B
(n=4) v=135, sz =0.4, d=1, Ø=160, z=16,
L=1352.16 t = 0.78 *8
9. Chamfering t = 1 (say)
Total machining time (exclusive of allowances and setting time) T = 51.416
Total machining time (assuming 12% allowance + setting time=30 minutes) T = 87.5859
Where v = cutting speed in m/min,
d = depth of cut in mm,
sz = feed in mm/tooth,
f = feed in mm/rev. ,
Ø = dia. of cutter for milling or drilling / diameter of previous hole for boring in mm,
z = no. of teeth on milling cutter,
n = no. of passes/cuts per surface
= no. of holes,
L = length of cut
= length of workpiece + approach of the drill (0.2 Ø) + length of the drill point (0.29 Ø)
+ overtravel (0.29 Ø) ----- for drilling
= length of the work + approach length ( 0.5*( Ø-( Ø2-B2)^0.5 ) for milling,
where B=width of workpiece.
66
Fig. 18a – Pictorial sequence of machining of base plate 1
67
Fig. 18b – Pictorial sequence of machining of base plate 1
Cost of machining base plate (C1) = Rs. 1751.178 /- approx.
68
8.2 Process sheet for base plate 2
Sr.
No.
Operation
sequence Cutting parameters [3] [6] [7]
Machining time
(minutes)
1. Face mill surface F
(n=1)
v=110, sz=0.30, d=3.5, z=16, Ø=150,
L=1116.262 t = 0.99 *2
Repeat this for surface E
2. Face mill surface C
(n=1)
v=110, sz=0.30, d=3.5, z=16, Ø=150,
L=409.261 t = 0.365 *2
Repeat this for surface D
3. Face mill surface A
by (n=3)
v=110, sz=0.30, d=2, z=16, Ø=150,
L=1145.308 t = 1.022 *6
Repeat this two more times
Face mill surface B in a similar manner
4. Drill Ø21 holes
(n=8) v=33, f=0.30, Ø=21, L=67.49 t = 0.44 *8
Drill 8 holes in all
Ream Ø22 holes
(n=8) v=20, f=0.6, Ø=22, L=68.18 t = 0.39 *8
Ream 8 holes in all
5. Bore to Ø32*35mm
(n=8)
v=31, f=0.25, d=2.5, L=35, Ø=22 v=31, f=0.25, d=2.3, L=35, Ø=27
v=33, f=0.125, d=0.2, L=35, Ø=31.6
t = 0.32 *8 t = 0.38 *8 t = 0.84 *8
Bore 8 holes in all
6. Drill Ø16 holes
(n=4) v=30, f=0.25, Ø=15, L=63.35 t = 0.398 *4
Ream Ø16 holes
(n=4) v=20, f=0.3, Ø=16, L=53 t = 0.44 *4
Drill and ream 4 holes in all
69
7. Drill Ø30 hole
(n=2) v=35, f=0.30, Ø=25, L=70.25 t = 0.525 *2
Bore to Ø30*53mm v=31, f=0.25, d=2.25, Ø=25, L=53
v=33, f=0.125, d=0.25, Ø=29.5, L=53 t = 0.537 *2
t = 1.1907 *2
8. Drill Ø25 holes
(n=2) v=35, f=0.35, Ø=25, L=70.25 t = 0.45 *2
Ream Ø26 holes
(n=2) v=20, f=0.65, Ø=26, L=70.94 t = 0.445 *2
Bore to Ø38*30mm
v=32, f=0.236, d=3, L=30, Ø=26 v=31, f=0.25, d=2.5, L=30, Ø=32
v=34, f=0.125, d=0.3, L=30, Ø=37
t = 0.32 *2 t = 0.389 *2
t = 0.8205 *2
9. Tap M24 holes
Drill Ø21 holes v=33, f=0.30, Ø=21, L=67.49 t = 0.44 *2
Tap M24*3 holes v=12, f=0.4, Ø=24, L=53 t = 0.83 *2
Drill and tap 4 holes in all
10. Finish mill all surfaces
Surfaces E and F
(n=2)
v=135, sz=0.4, d=1.5, Ø=150, z=16,
L=1107.837 t = 0.60 *2
Surfaces C and D
(n=2)
v=135, sz=0.4, d=1.5, Ø=150, z=16,
L=404.837 t = 0.2208 *2
Surfaces A and B
(n=4)
v=135, sz=0.4, d=1.5, Ø=150, z=16,
L=1142.308 t = 0.623 *6
9. Chamfering t = 1 (say)
Total machining time (exclusive of allowances and setting time) T = 49.428
Total machining time (assuming 12% allowance + setting time=30 minutes) T = 85.35936
Cost of machining base plate 2(C2)=Rs. 1707.1872 /- approx.
70
8.3 Process sheet for tenon
Sr. No.
Operation sequence
Cutting parameters [3] [6] [7] Machining time
(minutes)
1. Face off 3mm
Rough facing v=20, f=0.25, d=2, Ø=25, L=12.5 t = 0.196
Finish facing v=25, f=0.15, d=1, Ø=25, L=12.5 t = 0.261
2. Rough turn to Ø23*35 mm
v=35, f=0.30, d=1, Ø=25, L=12.5 t = 0.261
3. Rough turn to Ø18*17 mm
v=35, f=0.25, d=2.5, Ø=23, L=17 t = 0.1403
4. Make a groove of
Ø14*2 mm v=15, f=0.15, d=2, Ø=18, L=2 t = 0.0542
5. Finish turn to Ø16*15 mm
v=40, f=0.15, d=1, Ø=18, L=15 t = 0.1413
6. Drill and tap M6*20 mm hole
Drilling v=18, f=0.10,Ø=5, L=23.45 t = 0.2046
Tapping v=15, f=0.10,Ø=6, L=20 t = 0.251
7. Part off at 35 mm v=15, f=0.10, d=8, Ø=23, L=2 t = 0.096 *3
8. Finish turn to
Ø22*18 mm from the other side
v=45, f=0.15, d=0.5, Ø=23, L=18 t = 0.192
9. Face off 3 mm
Rough facing v=20, f=0.25, d=2, Ø=22, L=11 t = 0.152
Finish facing v=25, f=0.15, d=1, Ø=22, L=11 t = 0.202
10. Chamfer 2*45°, 3*15° t = 2 (say)
Total machining time (exclusive of allowances and setting time) T = 4.3434
Total machining time (assuming 12% allowance & setting time=15 mins.) T = 19.864
Cost of machining 8 tenons (C4) = Rs. 3178.24/-
71
8.4 Process sheet for locating pin
Sr. No.
Operation sequence
Cutting parameters [3] [6] [7] Machining time
(minutes)
1. Face off 3mm
Rough facing v=20, f=0.25, d=2, Ø=55, L=27.5 t = 0.9503
Finish facing v=25, f=0.15, d=1, Ø=55, L=27.5 t = 1.267
2. Rough turn to Ø51.2*68 mm
v=40, f=0.30, d=1.9, Ø=55, L=68 t = 0.979
3. Rough turn to Ø31*28 mm
v=30, f=0.30, d=2.6, Ø=51.2, L=28 v=30, f=0.30, d=2.5, Ø=46, L=28 v=30, f=0.30, d=2.5, Ø=41, L=28 v=30, f=0.30, d=2.5, Ø=36, L=28
t = 0.5004 t = 0.445
t = 0.4007 t = 0.3518
4. Finish turn to Ø30*28 mm
v=45, f=0.15, d=0.5, Ø=31, L=28 t = 0.4039
5. Chamfer 2*15° t = 1 (say)
6. Part off at 68 mm v=20, f=0.15, d=10, Ø=51.2, L=2 v=20, f=0.15, d=10, Ø=31.2, L=2 v=20, f=0.15, d=10, Ø=11.2, L=2
t = 0.107 t = 0.0653 t = 0.0234
7. Finish turn to
Ø50.2*40 mm from the other side
v=50, f=0.15, d=0.5, Ø=51.2, L=40 t = 0.857
8. Face off 3 mm
Rough facing v=20, f=0.25, d=2, Ø=50.2, L=25.1 t = 0.791
Finish facing v=25, f=0.15, d=1, Ø=50.2, L=25.1 t = 1.055
9. Chamfer 5*20° t = 1 (say)
Total machining time (exclusive of allowances and setting time) T = 10.1968
Total machining time (assuming 12% allowance & setting time=15 mins.) T = 26.4204
Cost of machining 2 locating pins (C5) = Rs. 1056.816/-
72
8.5 Cost of raw material
Total weight of set-up 1
= [ Volume of (base plate + support block + screwjack + round plate + bracket + clamp + clamp rest +
allen screws + stud + nut with washer + bolt + lock nuts) * Density of mild steel ]
+ (Volume of tenons * Density of EN 8)
= (48175.542 * 10-6 * 7850) + (33.8412 * 10-6 * 7845)
= 378.4434 kg
Total weight of set-up 2
= [ Volume of (base plate + support block + screwjack + round plate + bracket + clamp + clamp rest +
allen screws + stud + nut with washer + bolt + lock nuts) * Density of mild steel ]
+ (Volume of tenons * Density of EN 8) + (Volume of locating pins * Density of EN 24)
= (28236.83308 * 10-6 * 7850) + (33.8412 * 10-6 * 7845) + (184.8827 * 10-6 * 7872)
= 223.1442 kg
Total weight of T-shaped fixture
= Volume of (flange + t-shaped structure + rib) * Density of mild steel
= (468.769 + 1499.52 + 250) * 10-6 *7850
= 17.4135 kg
Hence, total weight of fixture = 619.001132 kg
Unit cost of raw material = Rs. 45/kg
Therefore, total cost of raw material (C5) = 45 * 619.001132 = Rs. 27855.05094 /-
*Total cost of fixture (excluding the machining cost of screwjack and t-fixture )
= C1 +C2 + C3 + C4 + C5 = 35548.47214 /- approx.
73
8.6 Process sheet for machining of columns
Cost of machining both the columns= Rs. 11784 /-
--------------------------------------------------------------------------------------------------------------------------------
74
9. Conclusion
Cost of machining the columns previously on Skoda machine = Rs. 45000/- approx..
Cost of machining the columns now on HMT machine = Rs. 11784/- approx.
Thus, the proposed design gives a cost benefit by a very large margin. This is because of the
changeover of the machining centre of the columns, and also due to a substantial reduction in the setting
time involved.
BEFORE AFTER
Total time required to machine
the columns previously on
Skoda machine
Total time required to machine
the columns on the proposed
HMT machine
% reduction in total machining
time
22.5 hours 9.82 hours 56.35%
----------------------------------------------------------------------------------------------------------------------
75
10. Testing
The proposed HMT centre (where the columns are to be machined) is currently overloaded with
other work schedules. Hence, unless the estimated targets are achieved, the given fixture design cannot
be tested there, and ultimately finalised. As such, the new production set up for the columns is on hold,
and they are being still machined on Skoda.
11. Scope for improvement
As far as the given project is concerned, we tried to reduce the set up time and cost by
proposing a new fixture design. And this design promises to give substantial savings. But, as such,
because of time constraints, there doesn’t seem anymore scope for improvement.
However, other than the project work, we do want to suggest some other changes that could
hopefully give fruitful benefits to the company in the long run. Firstly, the raw materials in the yard in
front of Hall no. 2 are not kept in an organized manner. Had we been associated with the company for
some more time, we could have thought over a new layout for storage which could have had different
predefined areas for storing different materials. Secondly, there is a need for a proper shed to cover
these materials. Aesthetically, that’s not a good sign. So that’s probably a grave point to contemplate on
its solution.
------------------------------------------------------------------------------------------------------------
76
12. References
1. CMTI Bangalore, Tata McGraw Hill Education Pvt. Ltd., 32nd
reprint
2. Donald Eary& Gerald Johnson, Process Engineering for Manufacturing
3. HajaraChowdhury, Elements of Workshop Technology, Media Promoters & Publishers Pvt. Ltd.,
Vol. 2 : Machine Tools, Twelfth Edition
4. Design Data, PSG College of Technology, DPV Printers
5. M.H.A. Kempster, An Introduction to Jig & Tool Design, ELBS, Third Edition
6. P. C. Sharma, A Textbook of Production Engineering, S. Chand & Company Ltd., Eleventh
Edition
7. Production Technology HMT Bangalore, Tata McGraw Hill Education Private Limited, 32nd
Reprint
8. R.S. Khurmi, J.K. Gupta, A Textbook of Machine Design, S. Chand & Company Ltd., Eurasia
Publishing House (Pvt.) Ltd., Fourteenth Edition
9. V.B. Bhandari, Design of machine Elements, McGraw Hill Education India Pvt. Ltd., Third
Edition
10. Catalogue of Komet group
Web links :
1.www.onesteel.com/images/db_images/productspecs/OSMB%20Technical%20Book%20Aug04.pdf
2. www.engineersedge.com/drill_sizes.htm
3. www.engineershandbook.com/Tables/drill2.htm
4. www.substech.com/dokuwiki/doku.php?id=alloy_steel_sae_4340
5. www.roymech.co.uk/Useful_Tables/Matter/Strength_st.htm
6. www.westyorksteel.com/EN24.html
7. www.steelo.com/AISI_1040.htm