DIRA DAWA UNIVERSITY
DIRA DAWA INSTITUTE OF TECHNOLOGY
SCHOOL OF MECHANICAL AND INDUSTRIAL ENGINEERING
Title
DESIGN AND MODIFICATION OF LAPIDARY MACHINE
By:
1. ABDI WOLDESMAYAT……………R/1051/08
2. DAWIT KERO………………………R/0709/08
3. TEMSEGEN MEKONNEN…………. R/0311/08
Project Proposal Submitted for the Fulfillment of Degree of Mechanical Engineering
Advisor: -
JANUARY 2021 Dire dawa Ethiopia
Abstract
In Ethiopia there are varieties of gemstones. But Ethiopians are not getting much of the
benefit out of it. In this paper the lapidary machine is analyzed very well and designed to solve the
problem of the existing machines to be applied in Ethiopia. The existing machines on the market are
either to cut the gemstones or to grind and polish them. This is costly because the three operations
are equally important, and people buy two machines for this task.
In this paper the design of lapidary machine includes the tools to operate all the three
operations with only one machine. This means reduces the cost of buying two machines. And it also
reduces cost incurred due to importing the machine from abroad. All the parts of the machine are
simplified to manufacture. In this project the potential sites of gemstone production in Ethiopia as
well as all over the world is explored based on the data gained from different websites.
.
Design and modification of lapidary machine 2020/21
LIST OF TABLE
Table2.1 types and hardness values of different gemstones ................................................................ 3
Table 6.1 Detail list of activities ........................................................................................................ 12
Table 6.2 Cost of Parts ....................................................................................................................... 13
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LIST OF FIGURE
Figure 2.1 Pictures of Opal from Around the World ...................... 5Error! Bookmark not defined.
Figure 2.2 Ethiopian opals .............................................................. 6Error! Bookmark not defined.
Figure3.1 Structural design and simulation of light weight Formula 1 flow chartError! Bookmark
not defined.
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Contents
ABSTRACT .............................................................................................................................................. I
CHAPTERT ONE ..................................................................................................................................... 1
INTRODUCTION..................................................................................................................................... 1
1.1. Introduction ......................................................................................................................................................... 1
1.1.1 Product Description and Application .................................................................................................................... 1
1.2. Statement of Problem .......................................................................................................................................... 2
1.3 Objective of the Research ..................................................................................................................................... 2
1.3.1 General Objectives ................................................................................................................................................ 2
1.3.2 Specific Objectives ................................................................................................................................................ 2
CHAPTER TWO ...................................................................................................................................... 3
LITERATURE REVIEW ............................................................................................................................. 3
2.1. Gemstone ............................................................................................................................................................ 3
2.1.1 Variety and hardness value (in mosh scale) of some gemstones ......................................................................... 3
CHAPTER THREE .................................................................................................................................... 7
METHDOLOGY ...................................................................................................................................... 7
3.1 Cutter Saw ............................................................................................................................................................ 8
3.2 Belt ....................................................................................................................................................................... 8
3.3 Pulley-1 ................................................................................................................................................................. 8
3.4 Pulley-2 ................................................................................................................................................................. 8
3.5 Shaft ..................................................................................................................................................................... 8
3.5.1 Key Way ................................................................................................................................................................ 8
3.5.2 Key (Square Type) ................................................................................................................................................. 8
3.6 Bearing ..................................................................................................................................................................... 8
3.7 Vice .......................................................................................................................................................................... 8
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3.7.1 Nut for Vice ........................................................................................................................................................... 8
3.7.2 Bolt for Vice .......................................................................................................................................................... 8
3.8 Frame.................................................................................................................................................................... 8
3.8.1 Bolts for the Frame ............................................................................................................................................... 8
3.8.2 Nuts for the Frame ................................................................................................................................................ 8
CHAPTER FOUR ................................................................................................................................... 10
SCOPE ................................................................................................................................................. 10
4.1 Scope .................................................................................................................................................................. 10
CHAPTER FIVE ..................................................................................................................................... 11
EXPECTED OUTCOME OF THE RESEARCH ............................................................................................ 11
CHAPTER SIX ....................................................................................................................................... 12
WORK PLAN ........................................................................................................................................ 12
6.1 Sequence of work ............................................................................................................................................... 12
BUDGET .............................................................................................................................................. 13
REFERENCE ......................................................................................................................................... 15
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CHAPTERT ONE
Introduction
1.1. Introduction
1.1.1 Product Description and Application
A gemstone or gem, is a piece of attractive mineral, which is used to make jewelry or other
adornments when cut and polished. Most gemstones are hard, but some soft minerals are used in
jewelry because of their luster or other physical properties that have aesthetic value. The most obvious
and attractive feature of gemstones is their color. In general, stones like ruby, sapphire, emerald, and
opal are gemstones where Amhara region (particularly Debre Brehan) is known to have opal in ample
quantity. Opal's mineral/chemical name is hydrated silicon dioxide where the most essential feature
of opal is its color, clarity and carat weight. The varieties of opal base color include chocolate, white,
yellow, orange, dark red, root beer, and caramel. Present Demand and Supply as stated earlier
gemstone is used by the jewelry industry. Processed products of Ethiopia are mainly exported to
Europe, America and Asia. In Ethiopia, there are a number of gemstone processing and exporting
firms including Ethio-Gemstone and Rift Valley Gemstone although a complete list of firms engaged
in the sector could not be documented. Nonetheless, in relation to world export figure, the export
from Ethiopia is insignificant both in quantity and value. According to official report of the sector,
the total global gemstone exports has been USD 46.4 billion in 2002, USD 48.4 billion in 2003 and
USD 57.9 billion in 2004. This suggests the presence of huge and growing demand in the market.
Information obtained from Rift Valley Gemstone Pvt. Ltd. Co. Divulges that the annual sales of the
firm are less than 1 million dollars per annum indicating how insignificant (less than 0.02%) the plant
is compared to the world demand. On the other hand, studies show that Ethiopian gemstone such as
opal is quite unique and different from more common Australian and Mexican opal. This confirms
the presence of potential demand provided standard products are delivered to the market. For this
reason, we choose to design lapidary machine so that the small scale private sector can assist the
overall economic growth and to create more job opportunities. It can also provide options for small
scale investments.
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1.2. Statement of Problem
Most of the time opal is exported as a row material meaning unprocessed. This is because peoples
do not have the knowhow about the gemstones. And those who know the stones do not have the
ability to import this expensive machine. This is a big west of resource if the country does not get
the required benefit. The market is so big that if government and private sectors engage in this
market, it supports the whole economy. It also reduces the rate of unemployment.
1.3 Objective of the Research
1.3.1 General Objectives
To design and modify lapidary machine
1.3.2 Specific Objectives
The specific objectives are
Designing safe machine
Reducing cost of the machine
Simplifying the machine
Designing the machine ease of maintenance
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CHAPTER TWO
Literature Review
2.1. Gemstone
A gemstone or gem (also called a precious or semi-precious stone, a fine gem, or jewel) is
a piece of mineral, which, in cut and polished form, is used to make jewelry or other
adornments. Most gemstones are hard, but some soft minerals are used in jewelry because of
their luster or other physical properties that have aesthetic value. Rarity is another characteristic that
lends value to a gemstone. Apart from jewelry, from earliest antiquity engraved gems and hard stone
carvings such as cups were major luxury art forms.
2.1.1 Variety and hardness value (in mosh scale) of some gemstones
Table2.1 types and hardness values of different gemstones
Type Hardness Type Hardness
10 9.5
Diamond Syth. Moissanite
8.5 9
Cubic Zirconia Corundum
8 8
Topaz
Spinel
7.5 – 8 7.5
Emerald Almandite
7 - 7.5 7 - 7.5
Rhodolite Pyrope
7 - 7.5 7 - 7.5
Spessartite Tourmaline
7 - 7.5 7
Iolite Quartz Group
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6.5 – 7 Jadeite 6.5 – 7
Peridot
6.5 – 7 6.5
Andradite Scapolite
6.5 6.5 – 7
Zircon (low) Tanzanite
6–7 6 - 6.5
Feldspars Nephrite
5.5 5–6
Opal Lazulite
5–6 5–6
Lapiz Lazuli Turquoise
5 - 5.5 5
Sphene Apatite
4 3–4
Rhodochrosite Coral
Opal is a hydrated amorphous form of silica; its water content may range from 3% to 21% by
weight, but is usually between 6% and 10%. Because of its amorphous character it is classed as
a mineraloid, unlike the other crystalline forms of silica which are classed as minerals. It is deposited
at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most
commonly found with limonite, sandstone, rhyolite, marl and basalt. .
The internal structure of precious opal makes it diffract light; depending on the conditions in
which it formed, it can take on many colors. Precious opal ranges from clear through white, gray, red,
orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the
reds against black are the rarest, whereas white and greens are the most common. It varies in optical
density from opaque to semi-transparent. Common opal, called "potch" by miners, does not show the
display of color exhibited in precious opal.
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Figure 2.1 Pictures of Opal from Around the World
Besides the gemstone varieties that show a play of color, there are other kinds of common
opal such as the milk opal, milky bluish to greenish (which can sometimes be of gemstone
quality); resin opal, which is honey-yellow with a resinous luster; wood opal, which is caused by the
replacement of the organic material in wood with opal; men lite, which is brown or grey; hyalite, a
colorless glass-clear opal sometimes called Muller's Glass; geyserite, also called siliceous sinter,
deposited around hot springs or geysers; and diatomite or diatomaceous earth, the accumulations
of diatom shells or tests.
The Ethiopian Welo Opal was only discovered in 2008. It differs from the Australian
Opal (AO) in many ways. It is found in nodules, whereas Australian Opal is found in very thin layers,
though both are found in seams as opposed to pockets and scattered in strata. The most sought after
and highest quality of AO is "black". So far there have been no confirmed black opals from Ethiopia,
but the quality of the fire of Welo opal matches if not exceeds the best AO has to offer.
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Figure 2.2 Ethiopian opals
As well as occurring naturally, opals of all varieties have been synthesized experimentally
and commercially. The discovery of the ordered sphere structure of precious opal led to its synthesis
by Pierre Gilson in 1974. The resulting material is distinguishable from natural opal by its regularity;
under magnification, the patches of color are seen to be arranged in a "lizard skin" or "chicken wire"
pattern. Furthermore, synthetic opals do not fluoresce under UV light. Synthetics are also generally
lower in density and are often highly porous.
Two notable producers of synthetic opal are the Companies Kyocera and Inamori of Japan.
Most so-called synthetics, however, are more correctly termed "imitation opal", as they contain
substances not found in natural opal (e.g., plastic stabilizers). The imitation opals seen in vintage
jewelry are often foiled glass, glass-based "Slocum stone", or later plastic materials.
Other research in macro porous structures have yielded highly ordered materials that have similar
optical properties to opals and have been used in cosmetics
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CHAPTER THREE
METHDOLOGY
Lapidary machine is a machine which is used to cut, grind and polish a gemstone. This machine
has cutting, grinding and polishing wheels rotating by a shaft which is connected to a motor through
a pulley.
The work piece material, shape, hardness, speed, stiffness, thermal, and chemical properties,
the abrasive tool, structure, hardness, speed, stiffness, thermal, and chemical properties, grain size,
and bonding the geometry and motions governing the engagement between the abrasive tool and the
work piece (kinematics) the process fluid, flowrate, velocity, pressure, physical, chemical, and
thermal properties The atmospheric environment the machine, accuracy, stiffness, temperature
stability, vibrations In grinding, it is essential that the abrasive grain is harder than the work piece at
the point of interaction. This means that the grain must be harder than the work piece at the
temperature of the interaction. Since these temperatures of short duration can be very high, the
abrasive grains must retain hot hardness. This is true in all abrasive processes, without exception,
since if the work piece is harder than the grain, it is the grain that suffers most wear.
The hardness of the abrasive is substantially reduced at typical contact temperatures between
a grain and a work piece. At 1,000°C, the hardness of most abrasives is approximately halved. Cubic
boron nitride (CBN) retains its hardness better than most abrasives, which makes it a wear-resistant
material. Fortunately, the hardness of the work piece is also reduced. As can be seen from Table 1,
the abrasive grains are at least one order of magnitude harder than hardened steel.
The behavior of an abrasive depends not only on hardness but on wear mode. Depending on
if wear progresses by attritions’ wear, micro fracture, or macro fracture determines if the process
remains stable or if problems will progressively develop through wheel blunting or wheel breakdown.
This range of alternatives means that productivity is improved when grinding wheels are best suited
for the particular grinding purpose.
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Components of machine
3.1 Cutter Saw
3.2 Belt
3.3 Pulley-1
3.4 Pulley-2
3.5 Shaft
3.5.1 Key Way
3.5.2 Key (Square Type)
3.6 Bearing
3.7 Vice
3.7.1 Nut for Vice
3.7.2 Bolt for Vice
3.8 Frame
3.8.1 Bolts for the Frame
3.8.2 Nuts for the Frame
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Start
Data
Identify the system & Create geometry by
integral form equation using Solid Work
Discretize the domain & approximate
Model generation from
the field variable of the elements
Solid Work
Evaluate the integral of each element &
assemble the global matrix equation Input material
constants
Mat Lab code for the system
equation
FE discretization
Invalid geometry
Input material constants
No No
Input boundary
Create 3D geometry using Mat Lab condition
Valid geometry
Solution
Input boundary
condition
Graphical
Solution display of results
Not Satisfied
Result 1 Result 2
Yes Comparison of Results Yes
Satisfied
End
Figure3.1 Structural design and simulation of light weight Formula 1 flow chart
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CHAPTER FOUR
Scope
4.1 Scope
The scope of this research design lapidary machine. Lapidary machine is a machine which is used to
cut, grind, polish and bore rock materials. Unlike the other lapidary machines this machine is designed
to do three operations. This saves money. The existing machines in the market, does not do these
three operations together. The market existing machines are designed to operate diamond also. But
in Ethiopia there is no diamond. So we don’t need those machines to cut, grind or polish diamond.
This machine is indigenized and can only cut the available stone in Ethiopia. In this thesis mechanical
design of machine, cost analysis, standard element selection, manufacturing process, operation
principle, cooling system of machine are clearly stated or considered. The machine equipped with
electric motor, gear, and pulley with belt. This thesis not only includes the design lapidary machine
but also it includes the design of vice to hold the work piece and fix it in position and to inhibit the
vibration during cutting time and to keep the cutting wheel from break down.
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CHAPTER FIVE
Expected Outcome of the Research
To introduce the machine to the people
To help small scale processing of the resource
To offer cheap machine to the users
Reduce imported machines
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CHAPTER SIX
Work Plan
6.1 Sequence of work
The schedule of the future work is shown below in the following table
Table 6.1 Detail list of activities
Activity Description Duration(Weeks)
1 Need /Aim identification 1
2 1st Data collection/ Literature review for writing introduction and 2
literature
3 Write Introduction 1
4 Write Literature Review 1
5 1st Contact advisor and 1st Comment collecting 1
6 2nd Data collection/ Literature review for Create a 3D model, model 1
generation, crate solution and review and wright the results
7 Create a 3D model by using SOLIDWORK 1
8 Model generation from 3D model. 1
Total 9
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Budget
The budget required for this research paper is shown below it also have a contingency cost.
Table 6.2 Cost of Parts
Part Part Name Mass In Kg Quantity Cost In Birr Total cost
Number of parts in
Birr
1 Pulley -1 5.14 1 371.108 371.108
2 Pulley-2 10 1 722 722
3 Cutter saw 6.339 1 457.67 457.67
4 Shaft 5.98 1 431.75 431.75
5 Key 0.222 1 16.02 16.02
6 Vice plates 6.264 2 452.26 452.26
7 Bolt for the vice 0.871 2 62.88 125.76
8 Nut For The Vice 0.205 2 14.80 29.6
9 Bolt for the Frame 0.1 4 7.22 28.88
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10 Nut For The Frame 0.058 4 4.18 16.72
11 Motor 1 3584.79 3584.79
12 Polisher and grinder 1 and 1 2712.555 2712.555
13 Frame 54.67 1 5685.68 5685.68
14 V-belt 5
15 Bearing 2
Total 30 14634.793
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Reference
[1] A Text Book Of Machine Design by “R.S. KHURMI J.K. GUPTA “ firist multi colored
edition
[2] Shigley’s Mechanical Engineering Design,Eighth Edition , Budynas−Nisbett”
[3] Handbook of Machining with Grinding Wheels by “Iona D. Marinescu, Mike Hitchiner,
Eckart Uhlmann, W. Brian Rowe, Ichiro Inasaki “
[4] Analysis of Grinding Wheel Loading for Electroplated Cubic Boron Nitride Wheels Used with
Water-based Lubricating Fluids by “Frank C. Gift Jr.” A Thesis Presented to the Graduate and
Research Committee of Lehigh University
[5]”http://lmrwww.epfl.ch/en/ensei/Rock_Mechanics/ENS_080312_EN_JZ_Notes_Chapter_4.p
df”
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