Chapter 1Introduction
Since the invention of the internal combustion engine in the early 18th century it has
become an integral part of daily transportation and always provided an area of further
development and innovation. The various transformations that this engine has brought in
the field of transportation range from small cars to huge truck’s, single seated bikes to
high capacity buses, everyday used family cars to luxury and even super sports cars. The
need for traveling faster as well as the requirement for carrying the right number of
people economically and emission friendly has led to a huge development in the various
aspects of automotive design and manufacture.
As stated in the title the need for a better design and development of a three wheeler was
opted and implemented considering all the design and manufacturing parameters needed
to fabricate an automobile.
A three wheeler is a vehicle with three wheels, either "human or people-powered
vehicles" (HPV or PPV or velomobiles) or motorized vehicles in the form of a
motorcycle, All terrain vehicle (ATV) or automobile. Other names for three-wheelers
include Trikes, Tricars and Cycle cars. The term Tricycle is used somewhat
interchangeably, but the term three-wheeler is more often applied to motor vehicles.
Many three-wheelers which exist in the form of motorcycle-based machines are often
called trikes and often have the front single wheel and mechanics similar to that of a
motorcycle and the rear axle similar to that of a car. Often such vehicles are owner–
constructed using a portion of a rear–engine, rear–drive Volkswagen "Beetle" in
combination with a motorcycle front end. Other trikes include ATVs that are specially
constructed for off road use. Three-wheeled automobiles can have either one wheel at the
back and two at the front, (for example: Morgan Motor Company) or one wheel at the
front and two at the back (such as the Reliant Robin).
1
Three-wheeler cars, usually micro cars, are often built for economy reasons, or as was the
case in the UK, to take advantage of tax advantages, or as in the US to take advantage of
the lower safety regulations, they are being classed as motorcycles. As a result of their
light construction and often relaxed pollution requirements, leading to higher efficiency,
three-wheeled cars are usually very economical to run.
The initial chassis or frame design was carried out in CATIA with a carrying capacity for
a single person and after acquiring the required materials the design was fabricated using
conventional manufacturing techniques. After the frame being constructed the placing of
the various parts was done with inline assembly and fabrication. Once the entire structure
and fabrication was completed paint and body work was carried out. Test runs have
claimed significantly economical and efficient running results.
1.1 History of the Three Wheeler
Similarities of a car with functionalities of a motorcycle the 3-wheeler, Cycle-car or even
Tri-car has had an important Impact in the development of the present day motor car.
From the beginnings of the Industrial Revolution in 1760 to the Concept cars of the
future, these vehicles can hold their headlamps up with pride. They were present at the
birth of motoring and possibly may well be the answer to the future with the constant
depletion of the Earths energy resources. A 3-wheeler offered in most cases a hood for
protection from the weather, side by side comfortable seating, easier steering and a
windscreen shielding everyone on board. To this the running costs were not much greater
than that for a motorcycle combination and considerably less than the 4-wheelers.The
major cost saving, derived from buying a 3-wheeler was its low taxation
One of the first mini-cars was the 3-wheeled Allard Clipper built by Sidney Allard.
Although production was limited these 3-wheelers, powered by a 346cc Villiers engine,
had a lightweight reinforced plastic body. lt was also fitted with the new Siba Dynastart
unit, which replaced the flywheel magneto. The Dynastart combined electric starter
motor, dynamo and cooling fan all into a single unit and became invaluable to the 3-
wheeler mini-car industry. In 1949 Laurie Bond began the production of a Bond mini-car.
2
This was introduced when petrol rationing was very much in force and any other form of
transport was both scarce and expensive.
Over the years there have been numerous new designs that have been developed of these
three wheelers by various companies. The immense potential of the vehicle
characteristics has made the adoption of this model design highly popular and versatile.
The transformation can be seen through the years with popular and prestigious companies
like BMW and Volkswagen adopting this design.
Fig: 1.1.1 A BMW Isetta 300 Fig:1.1.2 Volkswagen GX-3
The technological development of the three wheeler can be seen in its adaptation as a
sports vehicle not only in the recent years but also in the past. The earlier adaptation of
this design was seen in the Morgan Aero in 1932 as a two seater sports car and the more
recent one as the Campagna T-Rex in the year 1996.
Fig: 1.1.3 Morgan Aero 1932 Fig: 1.1.4 Campagna T-Rex 1996
3
1.2 General Production Procedure
In 1908 Henry Ford began production of the Model T automobile. Based on his original
Model A design first manufactured in 1903, the Model T took five years to develop. Its
creation inaugurated what we know today as the mass production assembly line. This
revolutionary idea was based on the concept of simply assembling interchangeable
component parts. Prior to this time, coaches and buggies had been hand-built in small
numbers by specialized craftspeople who rarely duplicated any particular unit. Ford's
innovative design reduced the number of parts needed as well as the number of skilled
fitters who had always formed the bulk of the assembly operation, giving Ford a
tremendous advantage over his competition.
Ford's first venture into automobile assembly with the Model A involved setting up
assembly stands on which the whole vehicle was built, usually by a single assembler who
fit an entire section of the car together in one place. This person performed the same
activity over and over at his stationary assembly stand. To provide for more efficiency,
Ford had parts delivered as needed to each work station. In this way each assembly fitter
took about 8.5 hours to complete his assembly task. By the time the Model T was being
developed Ford had decided to use multiple assembly stands with assemblers moving
from stand to stand, each performing a specific function. This process reduced the
assembly time for each fitter from 8.5 hours to a mere 2.5 minutes by rendering each
worker completely familiar with a specific task.
Ford soon recognized that walking from stand to stand wasted time and created jam-ups
in the production process as faster workers overtook slower ones. In Detroit in 1913, he
solved this problem by introducing the first moving assembly line, a conveyor that moved
the vehicle past a stationary assembler. By eliminating the need for workers to move
between stations, Ford cut the assembly task for each worker from 2.5 minutes to just
under 2 minutes; the moving assembly conveyor could now pace the stationary worker.
The first conveyor line consisted of metal strips to which the vehicle's wheels were
attached. The metal strips were attached to a belt that rolled the length of the factory and
then, beneath the floor, returned to the beginning area. This reduction in the amount of
4
human effort required to assemble an automobile caught the attention of automobile
assemblers throughout the world. Ford's mass production drove the automobile industry
for nearly five decades and was eventually adopted by almost every other industrial
Manufacturer. Although technological advancements have enabled many improvements
to modern day automobile assembly operations, the basic concept of stationary workers
installing parts on a vehicle as it passes their work stations has not changed drastically
over the years.
1.2.1 Raw Materials
Although the bulk of an automobile is virgin steel, petroleum-based products (plastics
and vinyls) have come to represent an increasingly large percentage of automotive
components. The light-weight materials derived from petroleum have helped to lighten
some models by as much as thirty percent. As the price of fossil fuels continues to rise,
the preference for lighter, more fuel efficient vehicles will become more pronounced.
1.2.2 Design
Introducing a new model of automobile generally takes three to five years from inception
to assembly. Ideas for new models are developed to respond to unmet pubic needs and
preferences. Trying to predict what the public will want to drive in five years is no small
feat, yet automobile companies have successfully designed automobiles that fit public
tastes. With the help of computer-aided design equipment, designers develop basic
concept drawings that help them visualize the proposed vehicle's appearance. Based on
this simulation, they then construct clay models that can be studied by styling experts
familiar with what the public is likely to accept. Aerodynamic engineers also review the
models, studying air-flow parameters and doing feasibility studies on crash tests. Only
after all models have been reviewed and accepted are tool designers permitted to begin
building the tools that will manufacture the component parts of the new model.
5
1.2.3 The Manufacturing Process
Components
The automobile assembly plant represents only the final phase in the process of
manufacturing an automobile, for it is here that the components supplied by more than
4,000 outside suppliers, including company-owned parts suppliers, are brought together
for assembly, usually by truck or railroad. Those parts that will be used in the chassis are
delivered to one area, while those that will comprise the body are unloaded at another.
Chassis
The typical car or truck is constructed from the ground up (and out). The frame forms the
base on which the body rests and from which all subsequent assembly components
follow. The frame is placed on the assembly line and clamped to the conveyer to prevent
shifting as it moves down the line. From here the automobile frame moves to component
assembly areas where complete front and rear suspensions, gas tanks, rear axles and drive
shafts, gear boxes, steering box components, wheel drums, and braking systems are
sequentially installed.
Fig 1.2.1 Workers install engines on Model Ts at a Ford Motor Company plant.
6
The automobile, for decades the quintessential American industrial product, did not have
its origins in the United States. In 1860, Etienne Lenoir, a Belgian mechanic, introduced
an internal combustion engine that proved useful as a source of stationary power. In
1878, Nicholas Otto, a German manufacturer, developed his four-stroke "explosion"
engine. By 1885, one of his engineers, Gottlieb Daimler, was building the first of four
experimental vehicles powered by a modified Otto internal combustion engine. Also in
1885, another German manufacturer, Carl Benz, introduced a three-wheeled, self-
propelled vehicle. In 1887, the Benz became the first automobile offered for sale to the
public. By 1895, automotive technology was dominated by the French, led by Emile
Lavassor. Lavassor developed the basic mechanical arrangement of the car, placing the
engine in the front of the chassis, with the crankshaft perpendicular to the axles.
In 1896, the Duryea Motor Wagon became the first production motor vehicle in the
United States. In that same year, Henry Ford demonstrated his first experimental vehicle,
the Quadricycle. By 1908, when the Ford Motor Company introduced the Model T, the
United States had dozens of automobile manufacturers. The Model T quickly became the
standard by which other cars were measured; ten years later, half of all cars on the road
were Model Ts. It had a simple four-cylinder, twenty-horsepower engine and a planetary
transmission giving two gears forward and one backward. It was sturdy, had high road
clearance to negotiate the rutted roads of the day, and was easy to operate and maintain.
An off-line operation at this stage of production mates the vehicle's engine with its
transmission. Workers use robotic arms to install these heavy components inside the
engine compartment of the frame. After the engine and transmission are installed, a
7
Fig 1.2.2 Automated Production Lines.
On automobile assembly lines, much of the work is now done by robots rather than
humans. In the first stages of automobile manufacture, robots weld the floor pan pieces
together and assist workers in placing components such as the suspension onto the
chassis.
Worker attaches the radiator, and another bolts it into place. Because of the nature of
these heavy component parts, articulating robots perform all of the lift and carry
operations while assemblers using pneumatic wrenches bolt component pieces in place.
Careful ergonomic studies of every assembly task have provided assembly workers with
the safest and most efficient tools available.
Body
Generally, the floor pan is the largest body component to which a multitude of panels and
braces will subsequently be either welded or bolted. As it moves down the assembly line,
held in place by clamping fixtures, the shell of the vehicle is built. First, the left and right
quarter panels are robotically disengaged from pre-staged shipping containers and placed
onto the floor pan, where they are stabilized with positioning fixtures and welded.
The front and rear door pillars, roof, and body side panels are assembled in the same
fashion. The shell of the automobile assembled in this section of the process lends itself
8
to the use of robots because articulating arms can easily introduce various component
braces and panels to the floor pan and perform a high number of weld operations in a
time frame and with a degree of accuracy no human workers could ever approach. Robots
can pick and load 200-pound (90.8 kilograms) roof panels and place them precisely in the
proper weld position with tolerance variations held to within .001 of an inch. Moreover,
robots can also tolerate the
Fig 1.2.3 Body Shop and Paint Shop.
The body is built up on a separate assembly line from the chassis. Robots once again
perform most of the welding on the various panels, but human workers are necessary to
bolt the parts together. During welding, component pieces are held securely in a jig while
welding operations are performed. Once the body shell is complete, it is attached to an
overhead conveyor for the painting process. The multi-step painting process entails
inspection, cleaning, undercoat (electro statically applied) dipping, drying, topcoat
spraying, and baking. Smoke, weld flashes, and gases created during this phase of
production.
As the body moves from the isolated weld area of the assembly line, subsequent body
components including fully assembled doors, deck lids, hood panel, fenders, trunk lid,
and bumper reinforcements are installed. Although robots help workers place these
components onto the body shell, the workers provide the proper fit for most of the bolt-on
functional parts using pneumatically assisted tools.
9
Paint
Prior to painting, the body must pass through a rigorous inspection process, the body in
white operation. The shell of the vehicle passes through a brightly lit white room where it
is fully wiped down by visual inspectors using cloths soaked in hi-light oil. Under the
lights, this oil allows inspectors to see any defects in the sheet metal body panels. Dings,
dents, and any other defects are repaired right on the line by skilled body repairmen.
After the shell has been fully inspected and repaired, the assembly conveyor carries it
through a cleaning station where it is immersed and cleaned of all residual oil, dirt, and
contaminants.
As the shell exits the cleaning station it goes through a drying booth and then through an
undercoat dip—an electro statically charged bath of undercoat paint (called the E-
coat) that covers every nook and cranny of the body shell, both inside and out, with
primer. This coat acts as a substrate surface to which the top coat of colored paint
adheres.
After the E-coat bath, the shell is again dried in a booth as it proceeds on to the final paint
operation. In most automobile assembly plants today, vehicle bodies are spray-painted by
robots that have been programmed to apply the exact amounts of paint to just the right
areas for just the right length of time. Considerable research and programming has gone
into the dynamics of robotic painting in order to ensure the fine "wet" finishes we have
come to expect. Our robotic painters have come a long way since Ford's first Model Ts,
which were painted by hand with a brush.
Once the shell has been fully covered 1 with a base coat of color paint and a clear top
coat, the conveyor transfers the bodies through baking ovens where the paint is cured at
temperatures exceeding 275 degrees Fahrenheit (135 degrees Celsius).
10
Fig 1.2.4 Mating of Body and Frame
The body and chassis assemblies are mated near the end of the production process.
Robotic arms lift the body shell onto the chassis frame, where human workers then bolt
the two together. After final components are installed, the vehicle is driven off the
assembly line to a quality checkpoint.
After the shell leaves the paint area it is ready for interior assembly.
Interior assembly
The painted shell proceeds through the interior assembly area where workers assemble all
of the instrumentation and wiring systems, dash panels, interior lights, seats, door and
trim panels, headliners, radios, speakers, all glass except the automobile
windshield, steering column and wheel, body weather-strips, vinyl tops, brake and gas
pedals, carpeting, and front and rear bumper fascias.
Next, robots equipped with suction cups remove the windshield from a shipping
container, apply a bead of urethane sealer to the perimeter of the glass, and then place it
into the body windshield frame. Robots also pick seats and trim panels and transport
them to the vehicle for the ease and efficiency of the assembly operator. After passing
through this section the shell is given a water test to ensure the proper fit of door panels,
glass, and weather stripping. It is now ready to mate with the chassis.
11
Mate
The chassis assembly conveyor and the body shell conveyor meet at this stage of
production. As the chassis passes the body conveyor the shell is robotically lifted from its
conveyor fixtures and placed onto the car frame. Assembly workers, some at ground level
and some in work pits beneath the conveyor, bolt the car body to the frame. Once the
mating takes place the automobile proceeds down the line to receive final trim
components, battery, tires, anti-freeze, and gasoline.
The vehicle can now be started. From here it is driven to a checkpoint off the line, where
its engine is audited, its lights and horn checked, its tires balanced, and its charging
system examined. Any defects discovered at this stage require that the car be taken to a
central repair area, usually located near the end of the line. A crew of skilled trouble-
shooters at this stage analyzes and repairs all problems. When the vehicle passes final
audit it is given a price label and driven to a staging lot where it will await shipment to its
destination.
1.2.4 Quality Control
All of the components that go into the automobile are produced at other sites. This means
the thousands of component pieces that comprise the car must be manufactured, tested,
packaged, and shipped to the assembly plants, often on the same day they will be used.
This requires no small amount of planning. To accomplish it, most automobile
manufacturers require outside parts vendors to subject their component parts to rigorous
testing and inspection audits similar to those used by the assembly plants. In this way the
assembly plants can anticipate that the products arriving at their receiving docks
are Statistical Process Control (SPC) approved and free from defects.
Once the component parts of the automobile begin to be assembled at the automotive
factory, production control specialists can follow the progress of each embryonic
automobile by means of its Vehicle Identification Number (VIN), assigned at the start of
the production line. In many of the more advanced assembly plants a small radio
frequency transponder is attached to the chassis and floor pan. This sending unit carries
12
the VIN information and monitors its progress along the assembly process. Knowing
what operations the vehicle has been through, where it is going, and when it should arrive
at the next assembly station gives production management personnel the ability to
electronically control the manufacturing sequence. Throughout the assembly process
quality audit stations keep track of vital information concerning the integrity of various
functional components of the vehicle.
This idea comes from a change in quality control ideology over the years. Formerly,
quality control was seen as a final inspection process that sought to discover defects only
after the vehicle was built. In contrast, today quality is seen as a process built right into
the design of the vehicle as well as the assembly process. In this way assembly operators
can stop the conveyor if workers find a defect. Corrections can then be made, or supplies
checked to determine whether an entire batch of components is bad. Vehicle recalls are
costly and manufacturers do everything possible to ensure the integrity of their product
before it is shipped to the customer. After the vehicle is assembled a validation process is
conducted at the end of the assembly line to verify quality audits from the various
inspection points throughout the assembly process. This final audit tests for properly
fitting panels; dynamics; squeaks and rattles; functioning electrical components; and
engine, chassis, and wheel alignment. In many assembly plants vehicles are periodically
pulled from the audit line and given full functional tests. All efforts today are put forth to
ensure that quality and reliability are built into the assembled product.
The growth of automobile use and the increasing resistance to road building have made
our highway systems both congested and obsolete. But new electronic vehicle
technologies that permit cars to navigate around the congestion and even drive
themselves may soon become possible. Turning over the operation of our automobiles to
computers would mean they would gather information from the roadway about
congestion and find the fastest route to their instructed destination, thus making better use
of limited highway space. The advent of the electric car will come because of a rare
convergence of circumstance and ability. Growing intolerance for pollution combined
13
with extraordinary technological advancements will change the global transportation
paradigm that will carry us into the twenty-first century.
1.3 Costs and Benefits
Compared to other popular modes of passenger transportation, especially buses, the
automobile has a relatively high cost per person-kilometer traveled. Nevertheless demand
for automobiles remains high and inelastic in rich nations, suggesting that its advantages,
such as on-demand and door-to-door travel, are highly prized, despite recent increases
in fuel costs, and not easily substituted by cheaper alternative modes of transport, with
the present level and type of auto specific infrastructure in the countries with high auto
usage.
Public costs related to the automobile are several; effects related to emissions have
received a lot of attention, however the impact of manufacturing and disposal is less well-
understood.
The costs of automobile usage, which may include the cost of: acquiring the
vehicle, repairs, maintenance, fuel, depreciation, injury, driving time, parking
fees, tire replacement, taxes, and insurance, are weighed against the cost of the
alternatives, and the value of the benefits – perceived and real – of vehicle usage. The
benefits may include on-demand transportation, mobility, independence and convenience.
Similarly the costs to society of encompassing automobile use, which may include those
of: maintaining roads, land use, pollution, public health, health care, and of disposing of
the vehicle at the end of its life, can be balanced against the value of the benefits to
society that automobile use generates. The societal benefits may include: economy
benefits, such as job and wealth creation, of automobile production and maintenance,
transportation provision, society wellbeing derived from leisure and travel opportunities,
and revenue generation from the tax opportunities. The ability for humans to move
flexibly from place to place has far reaching implications for the nature of societies.
14
1.4Disadvantages
Transportation is a major contributor to air pollution in most industrialized nations.
According to the American Surface Transportation Policy Project nearly half of all
Americans are breathing unhealthy air. Their study showed air quality in dozens of
metropolitan areas has worsened over the last decade. In the United States the average
passenger car emits 11,450 pounds (5,190 kg) of carbon dioxide annually, along with
smaller amounts of carbon monoxide, hydrocarbons, and nitrogen.
Animals and plants are often negatively impacted by automobiles via habitat
destruction and pollution. Over the lifetime of the average automobile the "loss of habitat
potential" may be over 50,000 square meters (540,000 sq ft) based on primary
production correlations.
Fuel taxes may act as an incentive for the production of more efficient, hence less
polluting, car designs (e.g. hybrid vehicles) and the development of alternative fuels.
High fuel taxes may provide a strong incentive for consumers to purchase lighter,
smaller, more fuel-efficient cars, or to not drive. Passenger car standards have not raised
above the 27.5 miles per US gallon (8.55 L/100 km; 33.0 mpg) standard set in 1985.
Light truck standards have changed more frequently, and were set at 22.2 miles per US
gallon (10.6 L/100 km; 26.7 mpg) in 2007. Alternative fuel vehicles are another option
that is less polluting than conventional petroleum powered vehicles.
15
Chapter 2 Literature
For the purpose or research and deriving required conclusions for building a vehicle, we
have referred a lot of study material both online and off. This study has not only
increased our knowledge over the subject but has also given us the key aspects required
for starting the build process. Here within is a part of the various documents that have
helped us in studying and building our project.
2.1 Pilch.org
The 3 wheeler project all started at Rugby College as part of a General Engineering
training course. We had to work in teams of 3 and come up with a project that included
design and manufacture of a product in 7 weeks. Our team consisted of an Electrical
Engineering graduate (Myself), an Electrical and Electronics graduate and a Mechanical
Engineering with Manufacturing Systems graduate. This represented a broad range of
experience and knowledge. One of the team members had an old motorcycle that had
suffered crash damaged; however the engine was still in good condition. We decided to
design and develop a new working vehicle in 7 weeks, with the overall aim of eventually
passing an MOT and getting it road legal.
We looked at the motorcycle to help us consider various vehicle options since our plan
was to use at least the existing engine. We identified a potential problem that the
motorcycle engine is design to power a chain, whereas in general 4 wheeled vehicles use
a drive shaft powering a differential. We decided that given time constraints and for
simplicity we would limit our ideas to three-wheeled vehicles, utilising the existing bike
engine and swing-arm for the back wheel. Therefore the design of the drive system
consisted of copying the mounting points from the motorbike to the frame design. This
not only simplified the drive system but also kept the cost of the project down because
existing parts were being used instead of having to purchase new ones. Given these
criteria we researched various three-wheeled vehicle options. The
16
website www.3wheelers.com provided an interesting A-Z history of three wheeled
vehicles. We also researched the legal requirements for self built three-wheeled vehicles,
to help us make it road worthy.
After the initial research, various sketches were produced to help decide on a style of
vehicle. It was decided early on that the vehicle would be a single seater to reduce weight
and design complexity. The aim was to keep the weight below 410kg which puts it in the
same category as a trike. This is covered by the B1 class on a standard driver’s license.
This class of vehicle was exempt until June 2003 from the SVA (Single Vehicle
Approval) test that other kit cars require to pass before becoming road legal. As long as
the car was registered with the DVLA before this delaine then it only has to pass a
standard MOT test to be road legal. This not only reduces the cost of the test but is less
strict than the SVA test. The car was registered with the DVLA and allocated with a
chassis number in May 2003.
To start planning the specific details of the vehicle, several methods were used. Firstly
MS AutoCAD was used to create a block sketch of the various components of the
vehicle. Using a CAD package allowed design changes to be made easily. To check the
design, a full size 2D plan of the vehicle was made on the floor using masking tape (see
below). This allowed various components to be laid out and for the driver to get a
realistic feel of the size of the vehicle.
The size of the single seater vehicle was determined by the following factors: The first
and most obvious factor is the driver size. The dimensions of the three team members
were measured. A comfortable driving position was also recorded.
Rear wheel and swing arm attachment are already determined from the existing frame.
Engine position. Since the chain from the engine needs to be taught when going over
bumps, the chain needs to be kept horizontal, limiting the engine position to in front of
the rear wheel. For safety reasons it was decided to keep the drivers feet just behind the
front axle, to allow for a small crumple zone.
17
It was decided to use a rack and pinion and wheel hubs from a 'donor' vehicle. These
would determine the width of the front of the vehicle. A ground clearance of 15cm was
chosen, similar to that of a normal road car, suitable to clear speed bumps. The size of the
drivers determined the minimum height of the vehicle, given that role bars were desired.
It was desired that the driver's arms would be contained inside the body of the vehicle;
therefore this sets a minimum width. It was decided early on to use the rear wheel, swing
arm, suspension and existing drive mechanism from the motorbike to provide the
suspension setup for the rear of the vehicle. It was decided to use a double wishbone
suspension system for the front of the vehicle. Due to the nature of such a bespoke car
design, the front suspension needed to be designed and built from scratch. This proved to
be a complicated part of the project and was critical to make sure that the vehicle handled
correctly under load. Some help and guidance from a certain Pro drive Suspension Guru
proved invaluable. Several key components played a major part in suspension
calculations and design. See the CMDT3 Suspension Guide for more details on
calculations and measurements. A rack and pinion was acquired from a scrap yard from a
Ford Sierra. The width of this set the width for the wishbones. For safety reasons we felt
it was important to have some of the car frame in front of the drivers feet position to
absorb some of the energy in the event of a crash. The plan of the car was designed in
AutoCAD before any manufacture began.
It was desired to make the wishbones out of seamless steel tubing approximately 20mm
in diameter. However, the local steel supplier did not have any seamless tubing in stock,
therefore seamed steel tubing was used, but a larger diameter (27mm) and thicker gauge
was used to increase the strength. The wishbones were joined to the frames using
brackets that were made by bending steel strips. The sides of the vehicle are not parallel
and therefore the angle of the brackets needed to be manufactured such that the axis of
the right and left wishbones were parallel. To ensure a smooth motion of the wishbones,
brass bushes were made, such that the brackets clamp to the bushes leaving the
wishbones free to rotate.
The ball joints for the top and bottom wishbones were sourced from local scrap yards.
Ball joints from a Ford Sierra were used for the bottom wishbones, these have now been
18
replaced with stronger, replacable Ford Cortina ones. Larger track rod end ball joints
were used from a Ford Transit for the top wishbones.
The size of the bottom wishbones obviously affects the size of the top wishbones. Once
the ball joints were acquired we then had to decide how to mount the ball joints to the
hubs. The wheel hubs were from a Ford Sierra, and therefore are designed to hold
McPherson strut suspension units. An extension unit was made to fit in the mounting for
the McPherson struts and hold the ball joints at the other end. The length of the extension
would determine the angle of the top wishbone. The vehicle needed to be designed such
that when the car is fully laden with the driver, the suspension system is in the desired
position. The ideal position of the wishbones in the fully laden position is such that the
bottom wishbones are level and the top wishbones angle down inline with the mounting
point of the ball joint and hub on the bottom wishbone on the opposite side of the car.
This was achieved by careful design of the suspension system.
The engine for the 3 wheeler is from a 500cc Kawasaki GPZ500 motorbike. The picture
below shows the engine mounted in the 3 wheeler frame at the same angle as it was in the
motorbike frame. The information below explains how this was achieved.
Engine & Swing Arm Mounting
The location of the mounting points for the engine, swing arm and rear suspension were
taken directly from the frame of the motor bike. This was achieved by creating a jig due
to the complex nature of the bike frame. Jigging the mounting points for the engine and
swing arm
The jig was nothing more than two pieces of chipboard with a large block of pine in
between. The jig was drilled to create a location or origin hole that all the mounting
points would be found from. The jig was then bolted into the frame of the motor bike.
This enabled the other mounting points to be located on the jig. The jig was then
removed, drilled and refitted to test the accuracy. As predicted all the holes lined up and
the jig was then measured to gain the dimensions for the engine mounting points and
swing arm.
19
Creating the rear mounting frame after studying the bike frame a design was decided on
that consisted of two vertical plates mounted on and separated by box section. The plates
were drilled using the dimensions from the jig and then joined together with the box
section. Once the frame had been produced that had the two rear engine mounts and the
swing arm pivot hole drilled the front engine mount was designed. It was clear that to
extract the engine from the frame with relative ease would mean that the rear engine
mount frame would need to be removable. This was accomplished, produced and works
well. Adding the rear suspension mounting points
To find the positions of the rear suspension mounting points, a jig was created that
consisted of bars with holes in that were bolted together. The main bar was drilled with
holes that exactly matched the rear engine mounts. The jig was then attached to the
existing bike frame by the rear engine mounting points and the top suspension mount.
The bolts in the jig were then tightened so that the location of the top suspension mount
could be located from the locations of the rear engine mounts. The jig was removed from
the bike frame and bolted into the rear mounting frame. A bracket was created and
welded in place whilst connected to the jig. This ensured that the accuracy was high. The
bottom suspension mounts position was calculated in the same way but it was decided
that to gain some more rear ground clearance the mounting point would be changed.
A problem that later occurred was that one of the engine mounting bolts was in the path
of the chain. This was corrected by creating another bracket that was welded into the
frame. This ensured a clear path for the chain. Adding the frame to the main body
Once the entire rear mounting frame had been created it was welded onto the main frame
of the car. Other struts were added to give strength that was needed to cope with the
forces that would be generated by the drive system.
Various options were considered for the paneling for the vehicle. The first option was to
not use any paneling and leave the frame exposed. This idea was rejected due to the
issues of wind on the driver and for aesthetic reasons. Obvious choices for paneling were
sheet aluminum or steel. Steel could be welded on, or either could be riveted or stuck on.
20
Before the decision had to be made, we were made aware that the college could acquire
large quantities of toughened foam, the type that is normally used for manufacturing
signs. We decided to use this, firstly because it was free, and secondly it is lightweight
and waterproof. It was decided to have several flat panels as opposed to bending
individual panels. Panel frames were welded together for the bonnet and rear for the
panels to be mounted to. This way the panels could be removed easily. The pictures
below show the bonnet and rear panel mounting frames.
The panels were not produced within the 6 week schedule. The joins will be sealed with a
paneling sealant and then smoothed down to leave a good finish. Cellulose paint has been
purchased, as this can be used in a compressed air spray gun. It has the added benefit
over enamel paint that it dries within 30 minutes and therefore if a mistake is made, it can
be rubbed down and reapplied very quickly.
2.2 Clevislauzon.qc.ca
Simple visual analysis of 3-Wheeler stability:
Fig: 2.2.1 Reactions at the Center of Gravity
Center of gravity position: Consider first a 4-Wheeler as seen from the rear, like here to
the right. If the vehicle is in a curve towards the left, for example, we can imagine that
a centrifugal force (magenta color) is exerted on the center of gravity (black and yellow
circle) of the vehicle-occupants system, while the vehicle’s weight exerts a
downward gravitational force (cyan color).
21
Thus, the centrifugal force (magenta) tends to roll the vehicle over towards the right,
around an imaginary point (deep blue) under the right tires, while the gravitational force
(cyan) holds the vehicle back to avoid rollover.
It’s as though the centrifugal force and the gravitational force combined together into
a resulting force (black) exerted on the center of gravity to turn it around this imaginary
point (deepblue).
We can thus easily understand that if the center of gravity height (red) is greater than
the half-track (in green) (the half distance between the two wheels seen from the rear),
the resulting force (black) will be aligned over the imaginary point (deep blue) and will
thus roll the vehicle over in a curve.
The ratio of the center of gravity height (red) to this half-track (green) thus plays a crucial
role in determining the stability against rollover of a 4-Wheeler. Ideally, this center of
gravity height (red) should be low like for a sports car, in order to insure a safety margin
against rollover. In the case of ‘sport-utility’ 4X4s, this height is relatively larger than for
regular family cars. This explains why these vehicles have a higher rollover propensity.
Fig: 2.2.2 Comparing 3 and 4 Wheelers
In the case of 3-Wheelers, another factor comes into play. As can be seen for a
4-Wheeler on the illustration at the right, the 4-Wheeler rolls over around a line
22
(blue) corresponding to the imaginary point (deep blue) of the previous illustration.
But in the case of a 3-Wheeler, the vehicle rather rolls over around a line (blue) going
from the unique wheel to one of the two symmetrical wheels. We can immediately see
that the green line between the center of gravity and the rollover line is thus shorter than
in the case of the 4-Wheeler, even though the center of gravity height, the length and the
track of the 3-Wheeler are the same as those of the 4-Wheeler.
The center of gravity height (red) is thus proportionately greater, which reduces the safety
margin against rollover in curves.
Moreover, a 3-Wheeler in a curve can also be subject to a braking or accelerating force
that will combine with the lateral centrifugal force, which may further increase chances
of rolling over of this 3-Wheeler. For example in the case of the single-front-wheel 3-
Wheeler, here above to the right, braking in a curve towards the left will increase chances
of rolling over this 3-Wheeler.
So in the case of a 3-Wheeler
- The center of gravity height should be low in relation to the half-track, like for a 4-
Wheeler.
- But the center of gravity's position also has importance: The farther it is from the two
symmetric wheels towards the single wheel, the shorter is the distance from the center of
gravity to the rollover line, which reduces the safety margin against rollover of the 3-
Wheeler compared to the 4-Wheeler.
Accelerating or braking in a straight line
When going straight, a 3-Wheeler may be accelerating or braking. Thus
Fig: 2.2.3 during Acceleration
23
It may tip backward while accelerating, as in the case of a two rear wheels 3-Wheeler
where the center of gravity is located too far back or while braking in the case of a two
front wheels 3-Wheeler illustrated at the right, it may roll around the blue point under the
front wheels and tip forward.
Fig: 2.2.4 during Breaking
Summarizing, the 3-Wheeler's center of gravity must be low and close to the two
symmetrical wheels, that are alone to avoid a rollover in curves.
But this center of gravity must not be too close to these two symmetric wheels, to avoid
tipping backward or forward. Basically, the center of gravity must be located under a
pyramid, as shown to the right in the case of a two-front-wheel 3-Wheeler, to avoid
rolling over sideways or tipping forward.
The height of the center of mass, shown in Figure 1, of a motor tricycle or a three-
wheeled vehicle shall not exceed one and a half times the horizontal distance from the
center of mass to the nearest roll axis
Fig: 2.2.5 Max. Height
24
So according to this regulation, the center of gravity height (in red) may thus be one and a
half times the green line between the center of gravity and the rollover line, as illustrated
at the right. The resulting force (black) may thus be aligned over the imaginary point
(deep blue) and roll the vehicle over in a curve.
Obviously, this regulation is very large if not too large; since it lets certain insufficiently
stable vehicles circulate on public roads.
As a counter part, this new regulation has the merit of bringing order to the world of two
and three wheel motorcycle definitions and regulation. Also, while avoiding going too
far, there are less chances of killing the touring motorcycle aftermarket, where goodwill
manufacturers can continue replacing single rear wheels by two rear wheels, on
motorcycles used by goodwill people that use them carefully and do not ride fast.
"The total weight of a motor tricycle or three-wheeled vehicle on all its front wheels, as
measured at the tire-ground interfaces, shall be not less than 25 per cent and not greater
than 70 per cent of the loaded weight of that vehicle."
Fig: 2.2.6 For Single Front Wheel
The image at the right illustrates the case of a single-front-wheel 3-Wheeler having its
vehicle-occupants center of gravity located at less than 25% of the wheelbase length from
the rear wheels. This leaves less than 25% of the weight on the front wheel.
25
Fig: 2.2.7 For Single Rear Wheel
The image below illustrates the case of a two-front-wheels 3-Wheeler having its vehicle-
occupants center of gravity located at more than 70% of the wheelbase length from the
rear wheel. This leaves more than 70% of the weight on the front wheel.
There is no 'mechanical' reason to treat differently these two types of 3-Wheelers: The
first could 'merit' 30% of the weight on its unique front wheel. Or the second could 'merit'
75% of the weight on its two front wheels.
In each of these two cases illustrated above, the vehicle-occupants center of gravity is
located below the pyramid, so that the single-front-wheel will not flip backwards when
accelerating and the two-front-wheel will not tip forward when braking.
Summarizing, there is no reason to treat differently the risk of overturning laterally
(rolling) and the risk of flipping backwards or tipping forward.
In both cases:
It seams more appropriate to consider overturning, flipping or tipping points or axes.And
to insure an adequate ratio between the vehicle-occupants center of gravity height and the
horizontal distance between the center of gravity and these points or axes, instead of a
weight percentage on the front wheels.
26
Chapter 3
Technology and Methodology Used
3.1 Technology used
In the following chapter a brief introduction of the various technologies that were used to
develop and help built the project are mentioned briefly.
3.1.1 CAD
CAD expended as Computer Aided Designing, is the replacement of the conventional
way of drawing 2D images in the process of designing. It makes use of various
algorithms and equations of higher order that define the locus of various points. For
the purpose of the build we have designed the component in CATIA (Computer Aided
Three-dimensional Interactive Application).
It is a multi- platform CAD/CAM/CAE commercial software suite developed by the
French company Dassault Systemes and marketed worldwide by IBM. Written in the C+
+ programming language, CATIA is the cornerstone of the Dassault Systemes product
lifecycle management software suite.
Commonly referred to as a 3D Product Lifecycle Management software suite, CATIA
supports multiple stages of product development (CAx), from conceptualization, design
(CAD), manufacturing (CAM), and engineering (CAE). CATIA can be customized
via application programming interfaces (API). V4 can be adapted in the FORTRAN
and C programming languages under an API called CAA (Component Application
Architecture). V5 can be adapted via the Visual Basic and C++ programming languages,
an API called CAA2 or CAA V5 that is a component object model (COM)-like interface.
Although later versions of CATIA V4 implemented NURBS, V4 principally used
piecewise polynomial surfaces. CATIA V4 uses a non-manifold solid engine.
27
Catia V5 features a parametric solid/surface-based package which uses NURBS as the
core surface representation and has several workbenches that provide KBE support. V5
can work with other applications, including Enovia, Smarteam, and
various CAE Analysis applications.
3.1.2 Cutting Process
The conventional method of cutting involves the process of rubbing a high friction hard
metal over the surface of the metal to be cut. This includes the use of saws, grinding
wheels and milling cutters. The basic process involved is to remove the metal in the form
of chips. For the fabrication purpose we have greatly implemented the abrasive cut off
saw to size the material.
An abrasive saw, also known as a cut-off saw or metal chop saw, is a power tool which is
typically used to cut hard materials, such as metals. The cutting action is performed by an
abrasive disc, similar to a thin grinding wheel. The saw generally has a built-in vise or
other clamping arrangement, and has the cutting wheel and motor mounted on a pivoting
arm attached to a fixed base plate.
Cutoff wheels are composed primarily of fibers, held together with a group of small
particles pressed and bonded together to form a solid, circular disk. Materials used are
generally silicon carbide and diamond bits with a vitrified bonding agent.
They typically use composite friction disk blades to abrasively cut through the steel. The
disks are consumable items as they wear throughout the cut. The abrasive disks for these
saws are typically 14 in (360 mm) in diameter and 7⁄64 in (2.8 mm) thick. Larger saws use
410 mm (16 in) diameter blades. Disks are available for steel and stainless steel.
3.1.3 Welding
One of the most common types of arc welding is shielded metal arc welding (SMAW),
which is also known as manual metal arc welding (MMA) or stick welding. An electric
current is used to strike an arc between the base material and a consumable electrode rod
28
or 'stick'. The electrode rod is made of a material that is compatible with the base material
being welded and is covered with a flux that protects the weld area from oxidation and
contamination by producing CO2 gas during the welding process. The electrode core
itself acts as filler material, making separate filler unnecessary. The process is very
versatile, requiring little operator training and inexpensive equipment. However, weld
times are rather slow, since the consumable electrodes must be frequently replaced and
because slag, the residue from the flux, must be chipped away after welding.
Furthermore, the process is generally limited to welding ferrous materials, though
specialty electrodes have made possible the welding of cast
iron, nickel, aluminum, copper and other metals. The versatility of the method makes it
popular in a number of applications including repair work and construction.
3.1.4 Painting
Painting is the process of covering the surface with a thin layer of permissible media,
which would dry up to form an opaque layer. This process is employed generally for the
purpose of improving the visual aid as well as to function as a protective coating against
corrosive elements.
We have employed the method of Spray Painting.This process occurs when paint is
applied to an object through the use of an air-pressurized spray gun. The air gun has a
nozzle, paint basin, and air compressor. When the trigger is pressed the paint mixes with
the compressed air stream and is released in a fine spray.
Fig: 3.1.1 Types of Nozzles and Sprays.
29
Due to a wide range of nozzle shapes and sizes, the consistency of the paint can be
varied. The shape of the work piece and the desired paint consistency and pattern are
important factors when choosing a nozzle. The three most common nozzles are the full
cone, hollow cone, and flat stream. There are two types of air-gun spraying processes. In
a manual operation method the air-gun sprayer is held by a skilled operator, about 6 to 10
inches (15–25 cm) from the object, and moved back and forth over the surface, each
stroke overlapping the previous to ensure a continuous coat. In an automatic process the
gun head is attached to a mounting block and delivers the stream of paint from that
position. The object being painted is usually placed on rollers or a turntable to ensure
overall equal coverage of all sides.
3.2 Methodology followed
A brief description of the methodology followed for building the project is mentioned in
the following steps. It can be considered as a regular engineering approach employed for
the production of a component.
3.2.1 Designing in CAD
For the purpose of designing, hand drawings of the model along with all the mechanisms
were roughly sketched to get the appropriate idea of where which part would fit in. This
has not only given the various mechanisms required but has also the visual aid for the
final component to be produced. This was further corrected and redrawn according to the
calculated scale based on assumptions and facts of various dimensions. Once this hand
drawing took its final shape it was then transferred into an engineering drawing with the
help of CATIA. This 2-D drawing produced in the sketcher was padded and extruded to
form the framed structure. During this process the figure was redesigned several times to
impart all the features of aerodynamics as well as to accommodate all the key features of
the frame
30
The design produced in catia was not only the replica of the hand drawings but also gave
the figure the appropriate shapes so as to ease the process of production. Thus the design
produced in catia standardized the various parts and helped in producing a final draft of
the structure.
3.2.2 Metal Cutting
As most of the metal involved in building the frame was derived from large pipes of
square and rectangle cross section, the various machining process involved were to cut
the metal and size it into the required lengths. Then the pieces were grinded and surface
finished so as to be mated with the compliment component.
For the purpose of cutting the metal two basic techniques of Gas cutting and Abrasive cut
off saw. The latter was not preferred due to the hazards involved in handling the
inflammable fluid and the improper cut and surface generated in this process. Hence we
have greatly used the cut off saw for most of the working operations.
All the required markings were taken and as per the draft and the appropriate edges were
tapered so as to fit in the structure. The cut portions were inspected and the burrs and
bruises formed during the cutting process were removed by grinding them on the table
grinder.
3.2.3 Arc Welding
The major portion of the frame was welded together so as to make it rigid and reduce the
vibrations produced in the various individual members. As the metal used was
dominantly mild steel, the process of arc welding was employed. This gave a robust and
permanent fixture of all the linkages in the frame. The welding operations had to be
carefully planned as any member fixed in the wrong position would affect the time
constraint as well as affect the strength of the material when it is removed and again
welded.
31
The welding process was followed by a through inspection. The portions were then
roughly grinded to remove the slack and irregular nuggets formed. Care was taken to
prevent the formations of large weld pools resulting in holes and gaps in the surface.
3.2.4 Painting Procedure
As the structure had several complex profiles, the conventional method of applying paint
with the help of a brush was dismissed. To overcome this problem, we used a spray gun
to spray an even amount of paint over the surface. This not only eased the job but also
provided a smooth surface without any visible patters produced by brushes. This process
greatly reduced the amount of paint consumed for the structure.
The same procedure was adopted to first apply two coatings of the primer over the basic
frame to protect the frame from corrosion and to act as a base for the final color. After the
primer had dried completely the final coating was applied to the structure.
32
Chapter 4
3-Wheeler Vehicle Parts
Given the time constraints of the project it was felt necessary to acquire some of the main
vehicle components from a 'donor' vehicle. The nature of a three-wheeled vehicle meant
that parts would be required from both a motorcycle and a car. The Bajaj Pulsar 180cc
that inspired the project would provide a large number of the parts.
The existing components of the donor vehicle were
• Rear wheel
• Swing arm
• Rear Suspension Unit
• 180 CC Engine
• Vehicles Electrics
• Rear Lights & Mudguard
Several other vehicle components like the steering rack, dampers, wheels, wheel mounts
and brakes assembly had to be scavenged of from a donor vehicle. The other components
like A- arms for suspension had to be manufactured accordingly. The vehicle components
and systems are discussed individually.
4.1 Chassis
The chassis or the frame of the vehicle was to be entirely built from scratch. A frame
capable of carrying the load of a single person at the same time rigid enough to withstand
all the impact and loading stress was to be built. The weight of the entire structure was to
be heavy enough to hold ground at the same time light enough to run with causing extra
load on the engine. Rigidity for the structure meant usage of steel and mild steel pipes of
preferably square cross section and heavy gauge was to be considered. The construction
method adopted was to weld the joints rigidly and mount the various parts on top of the
frame.
33
The initial design was also done using CAD software to get an accurate dimensioned
structure. The frame needed to hold good and withstand sudden heavy impacts. For safety
reasons we felt it was important to have some of the car frame in front of the drivers feet
position to absorb some of the energy in the event of a crash.
The lower portion of the chassis was covered by a 16gauge mild steel sheet metal to act
as the flooring as well as providing a protective casing for all the mechanical components
placed above it from mud and dirt
4.2 Suspension system
It was decided earlier on the build that the drive mechanism, the rear swing arm and the
rear suspension would be used of the motorbike. The design of the front suspension
entirely from scratch proved to be the most challenging complicated and critical part of
the vehicle. The vehicle needed to handle correctly under loading and cornering without
any glitches. A double wishbone suspension was decided and was to be fabricated
according to the design requirements. The vehicle needed to be designed such that when
the car is fully laden the suspension system is in the desired position. The ideal position
of the wishbones in the fully laden position is such that the bottom wishbones are level
and the top wishbones angle down inline with the mounting point of the ball joint and
hub on the bottom wishbone on the opposite side of the car. Therefore the mounting point
of the top wishbones on the frame also had to be decided. To reduce the forces in the
suspension system, it is desirable for the distance between the top and bottom wishbones
at their external points to be as large as possible. However, the greater this height is, the
higher the top wishbones need to be mounted on the frame. For aesthetic reasons it was
decided we didn’t want the wishbone mounting points sticking out of the bonnet,
therefore they were placed as high up on the frame as possible without protruding above
the line of the bonnet. This then generated a line from the opposite lower wishbones
through the mounting points and thus defining both the length of the upper wishbones
and the extension struts.
The final aspect of the wishbone suspension design was which spring and damper units to
use, and where to position them. The stiffness of the spring coils had to be calculated,
desirable to bear the load of the vehicle and give a comfortable ride. This desired stiffness
34
can be used with the spring stiffness to calculate what is known as the motion ratio of a
suspension system. Second hand dampers of motorcycle and scooters were the best
options and after the innumerable number of searches the right one was found which best
suited the calculations. Having attained the required stiffness of suspension springs, they
still needed to be mounted in a suitable location, such that the motion ratio was achieved.
There are limitless options for the two ends of the spring to be mounted. Therefore it was
decided to fix the position of one end, and then calculate a suitable mounting point for the
opposite end.
4.3 Steering mechanism
The rack and pinion was acquired prior to the initiation of the build since it was needed to
confirm the design of the frame. The rack and pinion used was that of the Maruthi
Ominis’. The steering wheel was to be placed exactly in the right position of a free and
comfortable motion; it was taken of the same donor car. A new mounting plate was
welded to hold the column in the right position. The column was fixed in such a position
that optimum steering wheel position and angle was determined. A frame was welded
onto the main chassis to support the steering column.
4.4 Engine
The engine is the main power source where the chemical energy of the fuel is converted
into thermal energy and pressure energy used for pushing the cylinders and generating
torque. The following topics discuss the functionality of the engine used for our build.
4.4.1 Engine mounting and assembly
The engine used was that of Bajaj Pulsar with an 180cc capacity. The entire engine
assembly including the transmission, drive mechanism, rear suspension and swing arm of
the bike were used. The engine has a five gear transmission with a chain drive
mechanism. As the engine suited all our requirements without flaws, there were no
further alterations made to it.
35
4.4.2Transmission modification and assembly
The gear shift actuation mechanism was to be customized and altered according to the
requirement. The motorbike gear shift was actuated by foot, but whereas in this case it
needed to be actuated by hand. The gear shift was modified suitably enough to fit
linkages from the shifter with the help of brackets to the right position comfortable for
the driver. A shifter mounted on a pivot fixed to frame had been built. The shift
mechanism was similar to that of the bike. The linkage converted the motion of the
shifter from around the horizontal axis to around the vertical axis translating it into a
forward and backward motion of gear shift.
The clutch actuation was given to the foot from the hand as in the bike. Suitable pedals
assembly was taken of a donor car and modified to the requirement. Modified cables
were made for the purpose of transmitting the controls from the pedals to the mechanisms
as per the dimensions of the vehicle.
The throttle actuation was also controlled with a foot pedal. The accelerator pedal was
that of the Maruthi Omni and placement was similar to that seen in a car. The cable was
similar to that used for the clutch and right throttle timing was to be adjusted. The idling
also was configured according to the tension in the cable and by setting the timing in the
carburetor; a quick and accurate throttle response was set.
4.4.3 Braking
For the purpose of breaking we have considered the use of the drum break already
existing in the rare wheel of the bike as it would sufficiently provide us with the required
control. We have eliminated the hydraulic breaking for the front wheels as it would
complicate the integration of both the breaking systems onto the same pedal thus
requiring another pedal to actuate it. Another reason behind this decision was to avoid the
locking of the front wheels during sudden breaking and thus reducing the steer control
36
4.4.4 Fuel System
The fuel system consists of a 4ltr capacity fuel tank which is mounted on the frame at a
suitable height. The location and height of the fuel tank was crucial as the fuel supply
was based on gravity. Thus we had to minimize the number of bends in the flow lines and
find a sufficient place where it can be harnessed without any disturbances. The fuel
supply from the hose was transferred to the carburetor of the engine where it is mixed
with air to form the required mixtures at various throttling conditions. This then traveled
to the engine where it undergoes combustion for producing energy.
4.4.5 ElectronicsFor the purpose of controlling various mechanisms with the help of switches, electrical
energy was used. The power for this system was generated from a 12V battery. The basic
components that depended on the electrical energy were:
Lights
The lights are very crucial components which not only allow the driver to see during poor
driving conditions of darkness and fog but also perform the work of a signaling device to
warn drivers coming from the opposite end. They were directly connected to generate
power only when the vehicle was running so as to reduce the consumption of battery as
well as reducing the loss of power when they are not required under stop conditions
Horns
The horns as the lights constitute a mechanism not directly providing mechanical use for
the vehicle but as a form of signaling and safety device, that need to be actuated only
when required. This was connected to the battery and would function when ever the
ignition key was in ON position.
37
Ignition
The ignition of the vehicle was controlled by a small switch which actuated a 12V
electric motor. The motor provided the initial torque required for cranking the engine so
as to start it. The switch was a spring loaded push switch.
Cooling Fan
As the air cooled engine used was not given the proper ventilation due to its placement
constraints, a cooling fan was provided in front the engine to generate the flow of air over
the fins. This ensured proper cooling of the engine during running conditions. The
radiator fan was given a direct supply of power so that it could be run even when the
engine was turned off to accommodate faster cooling
All the controls for the electrical systems were paneled onto a dash board close to the
steering wheel so that they can be easily accessed by the driver when ever called for.
38
Chapter 5Problem Statement and Solving
Based on the interest and through research in the field of automobile engineering, we
have taken up the challenge of building a vehicle with the minimum possible mechanical
constraints required for a body to be stable (Three Supports), without the difficulties of
control and stability faced by the general three wheelers. We have designed the model in
parametric CAD software CATIA, and have fabricated the frame in real time with the
required adaptations in design as per the mechanisms used.
5.1 Design:
For every engineered component be it big or small a proper Design must be first
developed. Developing a design follows a certain rules that are to be followed and these
rules help in standardizing the design so that it can be understood by ever one who has to
refer the design for further enhancement of the product in the future stages.
Basically there are two types of designs that are classified based on the way they are
created they are, Creative Design and Adaptive Design. In the following topics we shall
discuss these two types of designing and how we have used them in developing our
model.
5.1.1 Creative design
A design is called a creative design if the designer completely designs a new product
without the reference of previous designs of similar products or when no similar product
exists in the market and a new design is to be developed as per the requirements.
39
For such a design, the designer must carefully study a variety of parameters which are the
basic inputs for the design. The parameters include a list of requirements of the end
product. The performance of the product in real life, the environment the end product will
work in and such various other requirements. Along with this basic information, the
designer must also consider the materials required for the production of the end product
and the manufacturing procedure adopted for producing the component. While specifying
these considerations the designer must make sure that the materials used and the
manufacturing procedure involved are cost efficient as well as of the best quality.
Hence creative design is a very laborious and tedious process, and may always be
followed by adaptive designing over the long run of the production of the product based
on its running conditions and changes required for better performance.
5.1.2 Adaptive Design
A design is said to be an Adaptive design when the basic structure and shape of the
product are copied from an already existing model. This type of designing is basically
used for redesigning components which need structural changes for either better
performance or to reduce cost and improve quality of a product.
Adaptive designs are also used to create components which have similar structures but of
different shapes used for different purposes. As it is highly difficult to produce a new
design concept for every new product produced the designer can study other similar
products already existing in the market and with the help of the basic key features from
the existing product, he can create a new product with similar functionality or even
improved usage.
With the development in technology there has been a vast requirement for redesigning of
the existing models, for getting more compact and sleeker products. Thus Adaptive
designing is a field of real high importance in the design industry for the development of
the industry.
40
5.1.3 Designing the Trike
As discussed above the design of the trike can be considered as an Adaptive design. For
the design procedure the basic input parameters that we have considered are:
• Number of passengers
• Basic dimensions of the rider
• Type of steering used
• Wheel base
• Height of the vehicle
• Overall length of the vehicle
Though we have initially planned on building a two seated vehicle, but due to the
constraints of length, cost of the build and the shortage of time we have decided for a
single seated trike. For this we have considered the basic shape of the various vehicles
already present in the market, such as the Myers Motors NmG (formerly the Corbin
Sparrow), Reliant Regal, Volkswagen GX3, Campagna T-Rex, etc., The shape was
finally decided for a sharper aerodynamic look as well as a design which would keep the
vehicle closer to the ground without round corners which tend to support the roll of the
vehicle, a feature which we didn’t to incorporate. Once we have decided on how we
wanted the vehicle to look we have gone to the next step of the design planning, the
dimensions of the build.
41
Fig:5.1 Visualizing Dimensions of Riders
For the dimensions we have basically considered the various sizes and shapes of all the
team members so as to get an idea of the best cabin space that would not make the
vehicle look too bulky nor be too congested for any of the drivers. Once we had the
average personality fixed in place, we have then considered the width of the wheel base
and the total overall length of the vehicle. For this we have purchased the complete
engine and transmission assembly of a 180 c.c. engine with a chain driven rare wheel. For
the purpose of wheel base, we have purchased the steering system of an old Maruthi
Omini, and have modified the dimensions of the structure according to it.
After all the external mechanisms such as the wish bone, the wheel assembly and the
steering assembly have been temporarily put in place we have constrained the entire
length of the vehicle to 8⅓ feet’s and the height of the vehicle above the ground as 20cm.
then the maximum height of the frame was taken as 2 1/2 feet. With these basic
constraints we have redesigned the structure of the frame in CATIA a parametric CAD
software. Once the length of the wheel base was decided, with all the weight
considerations the center of gravity was calculated using the simple calculator described
below.
42
Description Data EntryLength of Wheel BaseWeight on Front AxleWeight on Rear AxleWheelbase Center of Gravity behind front axle
Calculated
Reset
Fig: 5.2 Calculator for Center of Gravity
From the above table with assumed loading conditions we have calculated that the center
of gravity will be located around 5.3ft, which was around the position close to the seat of
the driver thus keeping the body stable during cornering. As we wanted to prevent the roll
of the vehicle which is a common danger in 3 wheelers, we have reduced the height of
clearance of the vehicle from the ground, to about 20cm.
Fig: 5.3 Design of Base Frame in CATIA
The base of the frame was generated in the sketcher work bench to the calculated
dimensions. After the base of the frame was generated, the side structures were built with
43
the linkages to support and distribute all the vertical loading. The rear vertical link which
played a very important role in properly distributing the load as well as well as defining
the shape of the vehicle, it was angled at around 15º so that it can support the weight of
the passenger as well as the weight of the engine placed exactly behind it.
Fig: 5.4 Assembly of Frame
A rectangular crossed beam structure was attached to the rear portion of the base to house
the engine; this was supported by a vertical and angular supports form the side and top to
secure the engine in its place and to prevent it from shocks and vibrations. Once these
were designed all the parts were assembled one after another in the assembly work bench
to make the complete structure. The following pictures show the base of the structure and
the complete assembled component.
Once the complete structure was designed the dimensions were drafted in the drafting
module. These drawings were given the required appropriate dimensions and were
printed for the further development of the model.
Thus we have incorporated and designed the complete frame of the vehicle based on the
external shapes of the existing vehicles and the other design considerations as mentioned
above. After a final design was produced we have started the fabrication process of the
frame.
44
5.2 Fabrication
The fabrication of the frame started with checking out for a right place to produce and
assemble all the components required for the build. For this we have consulted a Weld
shop as well as a Garage where the appropriate work was carried out in a step wise
manner. After the work place was set, the procedure for the build processes was started.
For this all the components required were listed and all the mechanisms which were to be
purchased were considered. This gave us two lists, a list which specified all the
components that were to be purchased and a list of all the components that were to be
built.
Parts to find
• Rear wheel
• Swing arm
• Rear Suspension Unit
• 180 CC Engine
• Cooling Fan
• Vehicles Electrics
• Rear Lights & Mudguard
• Rack and pinion
• Front wheel hubs and assembly from a rear wheel drive car
• Front suspension coil and dampers
• Front Wheels
• Steering Wheel, Column
• Lower Ball Joints for Suspension
• Cables for rear brake, clutch and accelerator
• Fuel Tank
• Driving Seat
Parts to make
45
• Space frame including engine and suspension mounts
• Paneling for frame
• A-arms
• Pedals and mounting brackets
• Miscellaneous mounting brackets and fixings
With this data we have listed out all the raw material to be purchased for the making of
the components. The following bill of materials was developed and the required
purchases have been made.
S. No. Part Name Qty Specification1 Square pipes 3 2*2 in, 20ft, M.S. Pipes2 Rectangular pipes 2 2*1 in, 20ft, M.S. pipes3 Sheet metal 3 4*5ft, 16gauge, M.S. Sheets4 Metal Strips 2 20ft, 1 in*3 mm, M.S. Strips
Fig: 5.5 Bill of Materials
Once the various components were purchased, they were individually assembled and
placed on the floor of the work shop to help in correcting the dimensions produced in the
actual drawings, so as to meet the requirements of the pre built mechanisms.
Fig: 5.6 Cutting and Resizing of Components
46
With the edited dimensions all the parts to be built and fabricated so as to make a frame
were decided. Then the cutting and sizing operation was executed to get the required
shapes and sizes of the linkages. These were further tapered and grinded where ever
required so as to ease the process of fabrication. Once all the linkages required for
building the base were produced, they were assembled with the wish bone assembly and
the front wheels.
After the base was secured, the engine was mounted on the specially designed frame at
the rear portion of the vehicle. The engine along with the rear suspension and the chain
drive assemblies were welded into position with special brackets to secure the whole
setup without any flaws. As the frame had to take both the load of the passenger and the
weight of the engine, special attention was given for the frame at this portion to make it
more robust and to ease the distribution of the weight to the connecting linkages
proportionately.
With the main base and the driving mechanism in place, the remaining portions of the
frame were produced. Then the assembly of the frame was coincided with the assembly
of the various mechanisms, so as to give a proper functional structure. This included the
housing for the A-arms, the Steering mechanism, Rack and Pinion assembly. This gave
the basic shape of the vehicle and was further improved by the addition of supporting
members where ever required.
Once the complete frame was built the structure was taken to the garage, where all the
mechanisms were given the required linkages and wiring for appropriate hand and leg
controls.
47
Fig: 5.7 Base Coating with Primer
The complete assembled vehicle was then transported to the Paint shop where all the
components were grinded and surface finished for the process of coating with paints.
Motor run hand grinders with emery papers of different grades were used to remove all
the weld nuggets formed and all the uneven surfaces on the structure. The structure was
then covered with body paste a composite substance which helps to smooth all the rough
surfaces and giving the body a smooth even finish. This was again grinded to allow it to
form a real thin layer over the surface of the metal. Once the structure took on a smooth
surface, it was covered with a primary coating which acts as both a base coat of paint as
well as a rust proofing agent. Then we have given another round of primer to make the
base more stable. After the base was completely dried up a good coat of automotive paint
was spray coated over the surface as the final coating.
48
Fig: 5.8 Final Paint Job
After the paint work was completed the vehicle was taken for all the electrical works,
which included wiring of lights, horn, cooling fan, ignition button. This was the final
stage of fabrication.
49
Chapter 6Results and Observations
The following results have been observed as the performance characteristics of the trike.
The results mentioned herein are the conclusions derived from visual observations. They
do not indicate the exact values and are approximated to the closest whole number. These
values formed the bases for the technical specifications mentioned.
6.1 Load Test
For the load test we have increased the loading in the number of passengers it can carry.
For this several test rides were done in open grounds by gradually increasing the number
of passengers on the vehicle. The vehicle gave some astonishing results by carrying a
total number of 6 passengers without any internal or external signs of problems.
This result has drawn two main conclusions about the maximum loading the engine can
withstand, of about 610 kgs (250kgs dead weight + 6x60kgs avg. wt. of each passenger).
It has also shown that the suspension can take much more weight, of about 1000 kgs,
without any signs of failure.
Max. Permissible Load for Engine = 600kgs
Max Permissible Load on the Frame = 1000kgs
6.2 Handling
The over all handling of the vehicle was found to be very smooth with very little
drawbacks. As the steering assembly was made up of components of different vehicles,
the cornering radius has dramatically increased thus requiring larger room for taking
turns. Apart from this there were no other visual drawbacks. On the other hand the
stability of the vehicle during sharp cornering at high speeds has been remarkable. It has
been observed that the wheels are always in traction with the ground and the driver does
not have any impact on his stability during these turns. This key feature was the result of
the intense care taken to keep the center of gravity as close to the ground as possible. This
has also proven the aim of developing a 3-wheeler with a minimum risk of undergoing
Roll during steep turns.
50
The other area of performance includes handling of the vehicle while over coming
various obstacles such as road bumps and speed breakers. The long drive for about
120kms, from Hyderabad to Jangoan over various types of terrains both on road and off
road have been the live testing factor to prove them. The individual suspension provided
for each wheel has provided the driver with a smooth and comfortable ride.
6.3 Other Parameters
Various other parameters have been observed which showed some outstanding
performances. A few of these results have been mentioned below.
• Fuel Economy 38-40 kmpl
• Top Speed 80kmph
• Breaking Distance at 40kmph 10feet
Most of the numerical values mentioned above are only indicative and may change
depending on the test conditions. Based on these tests and results observed the following
table for technical specifications has been developed.
51
General information
Model: Bajaj Pulsar 180
Year: 2003
Category: Sport
Engine and transmission
Displacement: 178.60 ccm (10.90 cubic inches)
Engine type: Single cylinder, four-stroke, air cooled
Power: 17.02 HP (12.4 kW)) @ 8500 RPM
Torque: 14.22 Nm (1.4 kgf-m or 10.5 ft.lbs) @ 6500 RPM
Fuel system: Carburetor UCAL- Mikuni BS29
Ignition: CDI
Bore X Stroke 63.5x56.4 (mm)
Transmission type Chain
Chassis, suspension, brakes and wheels
Front suspension: Individual Wishbone suspension
Front suspension travel 75 mm (3 inches)
Rear suspension: Triple rated spring, 5 way adjustable shock absorber
Rear suspension travel: 101 mm (4.0 inches)
Front tyre dimensions: 90/90-17
Rear tyre dimensions: 120/80-17
Rear brakes: Expanding brake (drum brake)
Rear brakes diameter: 130 mm (5.1 inches)
Physical measures and capacities
Dead Weight 250kgs
Power/weight ratio: 0.1270 HP/kg
Wheelbase 102inches
Fuel capacity: 5litres
Reserve fuel capacity: 1litre
Other specifications
Starter: Electric 12V full D.C.
52
Fig 6.1 Technical specifications
Conclusions
Future Scope
As the vehicle built had several constrains of time, finance and experience, it has a great
scope for future developments. The area of developments includes the following:
• As the engine can take more loads, the space frame can be redesigned to make it a
two or three seated vehicle.
• By modifying the transmission system and changing the control pedals, the
vehicle can be made more user friendly for the handicapped.
• Designing a steering assembly exclusively for this vehicle can enhance its control
while cornering.
• Redesigning all the external mechanisms adopted and standardizing them to meet
the exact requirements for this vehicle.
Several other parts can be further developed to enhance their performance. With the
availability of the most advanced automotive design and manufacturing technology the
future scope carried out by this vehicle is immense in a number of ways. Its development
in the past and present only suggest that it can be used from an everyday economic and
user-friendly car to a speedy roadster.
53
References
• www.wikipedia.com
• Pilch.org.uk
• Clevislauzon.qc.ca
• www.3wheelers.com
Text books : Automobile Engineering by Kirpal Singh,
Automotive Mechanics by William H Crouse and Donald L Anglin,
Theory of Machines by R. S Khurmi.
54