group

1. DEPARTMENTS OF MECHANICAL ENGINEERING
(Manufacturing stream)
DESIGN OF ANGLE PLATE JIG
GROUP MEMBERS
SECTION A SECTION B
NO
NAME ID NO
NO
NAME ID NO
1 YAYEH AMANU TER/1102/06 1 ZEWUDU MOLLA TER/1179/06
2 ZELALEM BEKALU TER/1170/06 2 ADDISALEMADIMASU TER/059/06
3 HAFTIEKIROS TER/4249/06 3 ALEMNEW DESALEGN TER/105/06
4 ABNET TEGEGNE TER/041/06 4 ASKALMEKONEN TER/164/06
5 ADMASUMAZAYE TER/074/06 5 BELACHEW TENAGNE TER/243/06
6 BERIHUNGENET TER/270/06
7 DESTAWDINKU TER/382/06
SUBMITED TO: MULATU M ( M.Sc)
SUBMITTED DATE: 15/5/2010 E-C

2. Abstract: This project is proposed method to design modified angle jig for the drilling holes
on given component. The paper gave a detailed definition of jigs and also identified the
numerous advantages that are associated with the use of jigs in manufacturing to include:
production increase, cost reduction, interchangeability and high accuracy of parts, reduction of
the need for inspection and quality control expenses, reduction of accident as safety is improved,
automation of machine tool to an appreciable extent, easy machining of complex and heavy
components, as well as low variability in dimension which leads to consistent quality of
manufactured products. The work also explained that since the design is dependent on numerous
factors which are analyzed to achieve an optimum output that jigs and should be made of rigid
light materials to facilitate easy handling.
In this paper we start from basic conceptual design of jig and come up with this model which can
satisfy theoretical concepts of jig design. The 3D model design done on Solid works.
Keywords: Solid work Work-Holding, Manufacturing, Production.

3. Chapter 1
1. Introduction
Jigs are manufacturing tools that are employed to produce interchangeable and identical
components. They are unique tool-guiding and work-holding devices designed specifically for
machining and assembling large number of parts.
Jig is device which holds work piece & locates or guides the tool relative to the work piece and
usually which is not fixed to the machine table. It is normally lightly in construction. Jigs are
further identified by their basic construction. The most-common open jigs are template jigs, plate
jigs, table jigs, sandwich jigs, and angle plate jigs. Typical examples of closed jigs include box
jigs, channel jigs, and leaf jigs. As a result jigs are eliminates the marking out, measuring, and
other setting methods before doing machining.
Jigs are used for drilling holes which must be accurately located, both in relation to each other &
to certain working surfaces and points; the location of the holes is governed by jig.
Jigs and fixtures eliminate the need for a special set up for every work-piece thereby facilitating
production and also ensuring that every work piece is manufactured within a predetermined
tolerance. Between the work and the cutting tool. Once the jig is properly set up, any number of
duplicate parts may be readily produced without additional set up.
Jigs are used on drilling, reaming, tapping, milling and tapping. There are many advantages for
using jigs in production. Jigs eliminate individual making, position in grand frequent checking.
This reduces operation time and increase productivity. There is no need for selective assembly.
1.2. Elements of Jigs
The body, Clamping devices, Locating devices, and Tool guide/bushes are the major elements of
jigs.
a) The Body
As the most outstanding element of jigs and fixtures, the body is constructed by welding of
different slabs and metals usually mild steel or by casting of cast iron. After the fabrication, it is
often heat-treated for stress reduction as its main objective is to accommodate and support the
job.
The different types of jig bodies are as follows:
 Channel body type – this is fabricated from the regular steel channel.
 Box body type – usually made very light, the box type jig body is adopted where a work-
piece needs drilling in various parts, hence the jig is fabricated to have a required amount
of drill bush plates.
 Plane body type – this is the most common type of jig body and is often applied when the
work-piece requires drilling or boring, hence the provision of drill bushes on it.

4.  Leaf body type – usually made from block of steel as it holds and supports heavy
components.
 Built-up body type – this is made from standard steel.
b) Clamping Devices
Without sacrificing efficiency and effectiveness, the clamping devices must be very simple and
easy to operate. Apart from holding the work-piece securely in place, the strong point of
clamping devices is its ability to withhold the strain of the cutting tool during operations. The
bench vice is a popular example of a clamping device. The need for clamping the work-piece on
the jig or fixture is to apply pressure and press it against the locating components, thereby
fastening it in the right position for the cutting tools. The familiar clamping devices include:
 Clamping screws – they are used for not too rigid clamping.
 Hook bolt clamp - a simple clamping device generally used where the normal clamping
tip cannot fit in.
 Latch clamp – this is a unique clamp which provides space for the loading and the
unloading of a work-piece through its latch or lid.
 Other clamping devices are the C – clamp, the Bridge clamp, and the Heel clamp,
c) Locating Devices
Made with hardened steel and with different designs, the pin is the most popular device applied
for the location of work-piece in jigs and fixtures. The pin’s shank is press-fitted or driven into a
jig or fixture. The locating width of the pin is made bigger than the shank to stop it from being
pressed into the jig or fixture body because of the weight of the cutting tools or work-piece.
The pins are classified as follows:
 Locating pins – the locating pins are used for the location of the work-piece when
completed or reamed holes have been provided on the work-piece. The two types of
locating pins are cylindrical and conical locating pins.
 Jack pins – jack pins also referred to as spring pins are used for the location of work-
piece whose dimension will vary during operation. The pin is designed to rise under
spring pressure or in the contrary the weight of the work-piece pushes it down. As the
position of the work-piece is firmly fixed, the locking screw is used to fasten the pin in
the desired position.
 Support Locating/Rest pins – these pins which ensure reliable and secure location are
made to be either curved or flat. Those with flat heads are often used to provide support
and location to machine surface, as more contact area is accessible during location.
Because of their stability, the head support locating pins are for supporting coarse or
rough surfaces during machining.
d) Jig Bushing or Tool Guide
Guiding parts like jig bushings and templates which must be wear resistant, interchangeable, and
precise, are used to locate the cutting tool relative to the component being machined. Jig bushes

5. are applied in drilling and boring, here for the drill to pass through, a bush fits into the hole of the
jig.
Bushes are mainly made of reliable grade of tool steel in order to ensure hardening at a low
temperature and also reduce the risk of fire cracking. Although, hardened steel bushes are
preferred for guiding reamers, drills, and taps, the guiding tool bushings can also be made of cast
iron.
The jig bushings are categorized into three: the linear wearing bushes, press-fit wearing bushes,
and renewable wearing bushes.
e) Fastening Devices-
These devices used to fix different parts of jigs on desire positions. The fastening devices are
generally standard and available in market. Sometimes it is design as per requirement.
Chapter 2
2. Objectives of the design
2.1 Main objective of the project
The main objectives of this project are to design angle plate jig that can drill 8 mm hollow on the
work piece.
2.2 specific objectives of the design
 Selecting appropriate material for each part of the jig.
 Designs of each parts of the jig with its geometric analysis.
 Produce high productivity to reduce unit cost and interchange ability to facilitate easy
assembly.
 Design of the forces analysis of the angle plate jig
2.3 Benefit of the project
The design is used in the real word industry like:
 It used in automobile industries.
 It used in aircraft industries.
 Fixtures used in numerically controlled machine tools.
 Other application of jigs and fixtures
(Plastic, textiles, consumer product industries)

6. Chapter 3
3. Selection of the design
3.1 Types of jig
There are many types’ jigs among from these the following are:
1. Template jig
This is the simplest type of jig; it is simply a plate made to the shape and size of the work piece
with the required number of holes made it. It is placed on the work piece and the hole will be
made by the drill. This type of jig is suitable if only a few parts are to be made.
Bushings may or may not be provided in template jig. The factor on which the availability of the
bushing depends is the number of jobs to be manufacturing.
2. Plate type jig
 This is an improvement of the template type of jig.
 In place of simple holes, drill bushes are provided in the plate to guide the drill. The work
piece can be clamped to the plate and holes can be drilled.
 The plate jig is employed to drill holes in large parts, maintaining accurate spacing with
each other.
3. Open type jig
In this jig the top of the jig is open; the work piece is placed on the top.
4. Channel type jig
 The channel jig is a simple type of jig having channel like cross section.
 The component is fitted within the channel is located and clamped by locating the knob.
5. Leaf type jig
It is also a sort of open type jig, in which the top plate is arrange to swing about a
fulcrum point, so that it is completely clears the jig for easy loading and unloading of the
work piece
6. Box type jig
When the holes are to drill more than one plane of the work piece, the jig has to be provided with
equivalent number of bush plates.
It is used where there is drilling at number of distinct angles. One side of the jig will be provided
with a swinging leaf for loading and unloading the work piece, such a jig would take the form of
a box.
We can select the appropriate jig in a matrix form below the table;
Types of
jig
Selection parameters
Fabrication
process
Number
of part
Quality
of jig
Total
load
application total rank
Template A A B A C 17 2
Angle
Plate
A A A B B 18 1
Open B B B C B 14 3
Channel B C B D C 11 5
Leaf C C B C B 12 4
Box type B D C D B 10 6

7. We have assumed A=4 B=3
C=2 and D=1
There for, we have select angle plate jig for our project design.
Chapter 4
4. Material selection
There are a wide range of materials from where jigs could be made, to resist tear and wear,
the materials are often tempered and hardened. Also, phosphor bronze and other non-ferrous
metals, as well as composites, and nylons for wear reduction of the mating parts, and damage
prevention to the manufacturing part is also used. Some of the materials are discussed below:
 Phosphor Bronze: phosphor bronze is used in the production of jigs for processes that
involve making of interchangeable nuts in clamping systems like vices, and also in
operated feedings that require screws. As the manufacturing of screws is very expensive
and also wastes a lot of time, the reduction of their tear and wear is often achieved by
using replaceable bronze mating nuts made with phosphor bronze.
 Die Steels: the three variants of die steel - high chromium (12 %), high carbon (1.5 to
2.3%), and cold working steels are applied in the production of jigs for the making of
thread forming rolls, as well as cutting of press tools. When alloyed with vanadium and
molybdenum for it to retain toughness at very high temperature, die steels are applied in
the fabrication of jigs that are used in high temperature work processes which include
extrusion, forging, and casting processes.
 High Speed Steels: high speed steels which contain more quantity of tungsten and less
quantity of chromium and vanadium have high toughness, harden ability, hardness
retention at high temperature, and good wear, tear and impact resistance. When
tempered, they are applied in the production of jigs for reaming, drilling, boring, and
cutting operations.
 Carbon Steels: when tempered with oil, carbon steels are applied in the making of some
jig parts which are exposed to tear and wear like the locators and jig bushes.
 Mild steels: mild steel which contain about 0.29% of carbon are very cheap and because
of their easy availability are often the choicest material for the making of jigs.
 Other materials for the making of jigs include: Nylon and fiber, steel castings,
stainless steel, cast iron, high tensile steels, case hardening steels, and spring steels.

8. Selection criteria
Part Material Availability cost Tear
and
wear
Easy to
fabrication
Hardness Stress
and
force
Total Rank
Body Mild
steel
A A C B B D 17 2
Cast iron A B A B A A 22 1
Carbon
steel
B C B C B C 15 3
Clamping Phosphor
bronze
C D B D B B 12 3
Cast iron A B A B A A 22 1
Mild
steel
A A C B B A 20 2
Locator Carbon
steel
B C A D A A 18 3
Stainless
steel
A A B B B C 19 2
Mild
steel
A B C A A B 20 1
Bush Cast iron A B A B A A 22 1
Mild
steel
A A C B B A 20 2
High
speed
steel
D C A C A A 17 3
Fastening
device
Mild
steel
A A C B B A 20 1
Carbon
steel
B C B D A A 18 2
We have taken the value of the grade is:
A=4 B=3 C=2 and D=1
After this we get the materials of each parts of jig
 For the body, clamping and bushing part cast iron is selected.
 For the locating device and fastening device also mild steel is selected.

9. Chapter 5
5. Design analysis of angle plate jig
The design of jigs and is dependent on numerous factors which are analyzed to achieve an
optimum output. Jigs should be made of rigid light materials to facilitate easy handling, as it has
to be rotated severally to enable holes to be drilled from different angles.
Drill jigs provide procedures for proper location of the work-piece with respect to the cutting
tool, tightly clamp and rigidly support the work-piece during machining, and also guide the tool
position and/or fasten the jig.
To achieve their expected objectives, jigs consist of many elements:
 Frame or body and base which has features for clamping;
 The accuracy and availability of indexing systems or plates;
 The extent of automation, capacity and type of the machine tool where jigs will be
employed;
 Bushes and tool guiding frames for jigs;
 The availability of locating devices in the machine for blank orientation, and
suitable positioning;
Auxiliary elements;
 The strength of the machine tool under consideration;
 The precision level of the expected product;
A proper design must also incorporate tolerances at the design stage for jig components that are
standardized.
5.1 Design consideration
The design of Jigs depends on the following factors:
 work piece and finished component size and geometry study,
 the machine size and capacity,
 the machine’s extent of automation, availability of clamping arrangement and locating
devices in the machine,
 the accuracy of the available indexing devices,
 the machine tools rigidity,
 the needed accuracy level in the quality of work to be produced,
5.2 geometric analysis of angle plate jig
5.2.1 Body of angle plate jig
The base length of the gig body may be selected as 3 times the length of the workplaces
for a better rigidity.
Therefore base length=3×100mm=300mm
And thickness of the jig body= l1 the jig bush=16mm

10. The working height h2 of the jig body is approximately equal to 1.5 to 2 times the outer
diameters of the workspaces.
Therefore h2=2×60mm =120mm
h1=2tp+h2 (including clearance)
=2×16+120
=152mm
5.2.2 Locator of angle plate jig
Especially design of locator can be used to for making oil hole. It can be fabricated as
follows l1, l2, l3, l4, d1and d2 are dimension of the locator.
l1 can be equal to thickness of the jig plate.
l1=16mm
l2=l4=15% to 20% of length of the work for button clamping.
l3=lW-(l2+l4)
d2= inner diameters of the workspace
=40mm
And d1=should be less than d2 to give the clearance = 5mm be assume. Then the inner
diameters of the locator d1=30mm
Selecting of clamping
Quick acting knob is selected for fast clamping of the workspace.
5.2.3 Drill bush (guiding bush)
Bushings are used to guide drills, reamers, and other tools into proper position on the work
piece. In the design of indexing type of drill jig the type of bushes used are; Drill have
tendency to wobble before starts drilling as a result hole produce are not straight, exact
position and as per size. To overcome this problem we used bush. it helps to guide position
and support cutting tool. The jig bushings are categorized into three:
 The linear wearing bushes,
 Press-fit wearing bushes,
 Renewable wearing bushes.
But for our project we have selected linear wearing or fixed bush
And we have given that the drilling hole is 8 mm. from this we can get the other dimensions
from the slandered table
d1=8mm, d2=16mm, d3=20mm
l1=20mm, and l2=16mm
After this we must select tolerances for design from the standard table of bush tolerance.
Inner diameter d1 bush= d1F7 running fit
D1=8 mm
= 8_−0.0033
+0.028

11. Outer diameters d2 bush=d2h6 press fit
D2=16mm
= 160.000
+0.007
5.3 Force analysis of angle plate jig
The standard formulae for the various forces associated with the operations of jigs and fixtures
are explained below:
𝑇𝑜𝑟𝑞𝑢𝑒 = 𝐾 × 𝐴 × 𝑓 × 0.8 × 𝑑 × 1.8 − − − − − − − − − − − − − − − − − − − 1
Thrust, T = 2 × K × B × f × 0.8 × d + (K × E × d × 2) − − − − − − − − − − − − − 2
Where d is the diameter of the drill.
A, B, E, and K are constants.
Also, Thrust/Drilling force, F = 1.16 × K × d(100 × 𝑠0.85 ) − − − − − − − − − − − −3
The Force acting on each of the lips
From equation,
But k is the material factor, and k, for cast iron = 1.5
d is the diameter of drill = 8mm (as indicated above
s is the feed rate = 0.17 mm/rev substituting,
Thrust/Drilling Force =1.16×K×d(100 × 𝑠0.85
) = 27.841×1.114 = 309.42Kgf
Therefore, Thrust/Drilling Force = 3094.2N

12. Pl =
𝐾×𝑙×𝑑×𝑠
4
4
The Torque, M is also calculated as
𝑃𝑙×𝑑
20
5
The clamping Force (Q) is given as
Torque (M)× safty factor 6
The constants for different work materials for the calculation of Torque (M) and Thrust
(T) are shown in the standard tables.
Where c= chisel edge length (mm)
d =diameters (mm)
w =web thickness (mm)
For adequate strength and rigidity, cast iron with 8 mm in diameter was chosen for the design of
a sample angle plate jig.
From equation 4, the Force acting on each of the lips Pl is given as:
Recall that Kl for cast iron =250
𝐾𝑔
𝑚𝑚2 d = 16mm, and s = 0.17 mm/rev
Therefore, the Force acting on each of the lips = 170Kgf = 1700N
From equation 5, The Torque M =
𝑃𝑙×𝑑
20
Substituting, Torque M =
1700 ×8
20
Torque, M = 1360N-mm
From equation 6, the clamping Force (Q) is given as:
Torque (M) ×safty factor
With a safety factor of 3, we have:
Clamping Force (Q) = 1360×3 = 4080N
Note: if the clamping force is greater than the thrust force the design is safe.
There for from the above analysis clamping force is greater than the thrust force. That means:
Clamping force >Thrust (drill) force 4080N>3094.2N so our design is safe.

13. Chapter 6
7. Manufacturing process
Manufacturing process can be simply defined as value addition processes by which raw material
of low utility and value due to its adequate properties and poor and irregular size shape and
finish are converted in to high utility and product with definite dimensions, forms and finish
imparting some functional ability.
Generally we can manufacture the part that is: the body, clamping and the locator firstly by using
casting method after that we can use the operation machining, milling, turning and drilling to get
the exact dimension of the part and the part to be smooth surface finish.
Procedures for the body:
 First manufacture the body by casting from cast iron material
 Mill the casted body to get desired dimension
 After this we can drill the body at the indicated point
 Finally machined the object
Procedures for the locator:
 Like manufacturing process of the body after casting we use the other operations
 By using lath machine turn the part until to get desired diameters
 After these process mill the part and turn simultaneously to get desired shape
 Finally machined the part to be became smooth surface
The machines we use to manufacture the parts are:
 Lath machine
 Milling machine
 Drilling machine
 Cutting machine and others like casting, modeling etc.

14. Chapter 7
7. Assembly procedures
In manufacturing processes assembly in which part are added as the semi-finished
assembly moves from workstation to workstation where the part are added in a sequence
until the final assembly is produced. By mathematically moving the part to moving
assembly work and moving the semi-finished assembly from work station to work station
a finished product can be assembled faster and with less labor than by having workers
carry part to a stationary piece for assembly.
The component or end item comprising a number of parts or sub assembly put together to
perform a specific function, and capable of disassembly without distraction. We can
assemble by the following step.
Step1. First put the body with appropriate position to balance the jig body.
Step 2. Insert the bush in to the upper parts of the body or at the top with its dimensional
accuracy.
Step 3. Insert the one side tip parts of the locator in to the body.
Step 4. Mount the work piece in to the locator and tight to the body.
Step 5. After this quick acting knob is attached to the locator and the body then clamp it
with available force.
Step 6. Finally drill the work piece and take out the final product.
Chapter 8
8. Cost analysis
Costs can be defined as the amount of expenditure made in order to secure some goods or
services. The analyses of cost for design of leaf jig can be broadly divide in to two these are
material cost and cost of fabrication and assembly cost.
8.1 Material Cost
The cost of each component of jig can be calculated by using density volume relationship, the
cost of material can be calculated from the formula and some components can be directly buy
from the market if the component is selected like c washer and link for pin.
The general formula for cost analyses is density= mass /volume
𝜌 =
𝑀
𝑉
Where 𝜌= density of the material
M= mass of the material
V =volume of the material

15. These from the market giving information what is the price of the material for the mass and then
if the mass of some material is known then we can calculate the unknown mass.
m1= x price m1 and x price is from the market.
m2 = y price m2 is calculated mass and y price is calculated cost of the part.
For body, clamping and bushing the material selected for these parts is cast iron then to find the
total mass of the those parts first find the mass, then to find the mass we can use density mass
and volume relationship.
For the other locator and fastening we have selected that milled steel then we can calculate the
material costs of each part. But first we must know the cost of each material in gram/ETB.
8.2 labor force for fabrication and assembly the whole part
After design analysis of the project we can go manufacturing of each component up to assembly of whole
angle plate jig the human worker can take in to account.
There for total cost is the sum of all material cost, manufacturing of each component labor cost, assembly
cost and machine deprecation cost. Manufacturing consists of activities to convert raw materials into
finished goods.
 Labor cost in the fabrication company
In the manufacturing company labors are employed for directly associated with converting raw
materials into finished goods by operating the machine
Part Selection parameters
Body Quantity Total
time
taken
ETB
per
day in
debre
markos
Manufacturing
cost
Assembly
cost
From single
process to
final=
Clamping
Locator
Bush

16. 8.3 machine depreciation cost
This cost is determined by the machine deprecation point that is the total time taken that can do the
machine time’s deprecation number for all machines.
Md = Total cost is the sum of all material cost + manufacturing cost + assembly cost + machine
deprecation cost.
Total cost=

17. Chapter 9
9. Conclusion
Thus the modified angle plate jig has been successfully designed and developed as per the
requirements of component. The usage of this jig will certainly help the industry in reducing the
production time & also reducing the production cost apart from increasing the productivity. The
cost incurred in the manufacturing of this jig can be obtained in the passage of time without
affecting the profit of the company.
9.1 feature work

18. References
[1] P H Joshi, “Jigs and fixtures” Tata McGraw-Hill Education, 2010
[2] Edward Hoffman “Technology & Engineering” Cengage Learning, 21-Aug-2003 [3] Cyril
Donaldson, V. C. Goold Machine-tools -Tata McGraw-Hill Education, 1976
[4] Rajput, R.K. (2010), “Strength of Materials” Revised Edition, S. Chand and Company
Limited.
[5] Rajput, R.K, (2007), “A Textbook of Manufacturing Technology” Laxmi Publications, 1st
Edition.
[6] Khurmi, R.S. and Gupta, J.K. (2005), “A Textbook of Machine Design”, Eurasia Publishing
House.

19. Appendixes
Constant table
Table 1 tolerances
Table 2 standerd bush size
Table 3.The work material constants for Torque and Thrust calculations. Source: Spogel (2014).

20. Work Material K
Carbon Steel, 300 Bhn 31,000
Cast Steel, 400 Bhn 34,000
Most aluminum alloys 7,000
Most magnesium alloys 4,000
Most brasses 14,000
Leaded brasses 7,000
Cast iron, 165 Bhn 15,000
Free-machining mild
steel, resulfurized
18,000
Austenitic stainless steel
(Type 316)
34,000
Table 4.Torque and Thrust constants based upon ratios c/d or w/d. Source: Spogel (2014).
c/d Approx. w/d Torque constant
A
Thrust constant
B
Thrust constant
E
0.03 0.025 1.000 1.100 0.001
0.05 0.045 1.005 1.140 0.003
0.08 0.070 1.015 1.200 0.006
0.10 0.085 1.020 1.235 0.010
0.13 0.110 1.040 1.270 0.017
0.15 0.130 1.080 1.310 0.022
0.18 0.155 1.085 1.355 0.030
0.20 0.175 1.105 1.380 0.040
0.25 0.220 1.155 1.445 0.065
0.30 0.260 1.125 1.500 0.090
0.35 0.300 1.310 1.575 0.120
0.40 0.350 1.395 1.620 0.160
Table: Torque and thrust terms feed, f , ipr based upon feed. /source: spongel (2014). Feed, f ,ipr
0.0005 0.0025 0.012 0.030
0.001 0.004 0.015 0.035
0.002 0.007 0.020 0.045
0.003 0.010 0.025 0.055
0.004 0.012 0.030 0.060
0.005 0.014 0.035 0.070
0.006 0.017 0.040 0.075
0.008 0.020 0.045 0.090
0.010 0.025

21. Drawing of the project
Part drawing
Assembly drawing of the project