The document summarizes a project to design a three-wheeled vehicle that can be driven by two riders simultaneously or alternately using electricity or pedaling. It details the vehicle design, estimated costs, team structure and timeline. Key aspects of the design include a full suspension system, safety features like lights, and a speedometer. The feasibility analysis considers factors like ergonomics, comfort, handling and the environmentally friendly electric design.

1. EFFICYCLE 2011
MACH8
6/29/2011

2. REPORT SUMMARY
Project Summary
The project involves designing and fabricating a three wheeled vehicle that can
be driven alternately or simultaneously by two riders and also alternately or
simultaneously on electricity. This vehicle must also be capable of carrying a
50 kg load. The vehicle was designed and validated using the latest software for
modelling and simulation, thus ensuring a robust design.
Project Cost
Body - 700
Transmission - 10000
Suspension - 2000
Brakes - 800
Tires - 500
Electronics &
Instrumentation - 2000
Miscellaneous - 2000
Total Cost - 18000
Team Structure
Team Members
 Ajay Kumar Valiathan -Wheels and Tyres
 Anand Krishnan V U (Captain) -Steering
 Arjun Raja K C -Suspension
 Barath V -Finance
 Narendran M -Transmission & Electrical
 Prasanna N -Brakes and Marketing
 Vignesh Kumar V -Design
Faculty Advisor – C. Lakshmikanthan
MACH8

3. Time Plan
Task Name Duration Start Finish
Study of resources 15 days Tue 5/10/11 Mon 5/30/11
Review of work 4 days Mon 5/30/11 Thu 6/2/11
Task allocation 4 days Mon 5/30/11 Thu 6/2/11
Chassis and
steering design
4 days Fri 6/3/11 Wed 6/8/11
Drive train
selection
4 days Fri 6/3/11 Wed 6/8/11
Suspension design 3 days Thu 6/9/11 Mon 6/13/11
Material Selection 2 days Tue 6/14/11 Wed 6/15/11
Brakes and Tires
selection
2 days Thu 6/16/11 Fri 6/17/11
Motor and battery
selection
3 days Sat 6/18/11 Tue 6/21/11
Electronics 3 days Sat 6/18/11 Tue 6/21/11
Final Design 1 day Wed 6/22/11 Wed 6/22/11
Preliminary Design
Report
5 days Thu 6/23/11 Wed 6/29/11
Preliminary Design
Presentation
5 days Thu 6/23/11 Wed 6/29/11
Fabrication 47 days Mon 8/1/11 Tue 10/4/11
Final Design Report 3 days Thu 9/1/11 Mon 9/5/11
Innovation/Distinct
Features
 Full suspension vehicle
The vehicle is provided with suspension on all the three wheels, making it a full
suspension vehicle. Fork Suspensions are used at the two front wheels while a
variable pitch coil spring suspension is used at the rear. The vehicle is
completely mounted on suspension, thus providing better ride ability and
comfort. Fork suspensions and coil springs are readily available at low prices.
 Safety features like head lights, tail lights and turning lights
The lighting system is powered by the battery. LED lights are used, ensuring
lower power consumptions and emissions. As such the implementation is
simple and inexpensive.
 Speedometer and battery level indicator
The instrument panel includes the speedometer and the battery level indicator.
The system uses mechanical actuators that respond to the changes in the vehicle
conditions. This ensures lower costs with better reliability.
Commercial
Feasibility
 Ergonomic design: The vehicle is designed ergonomically for an adult
driver of normal height and weight.
 Comfort: The semi recumbent riding position reduces strain on the
body, making it particularly suitable for long rides and touring.
 Easy handling: Fairly simple controls which are self-explanatory even
to a first time rider.
 Safety: Vehicle has good safety features for the drivers.
 Lesser Effort: Power available from both the drivers reduces the net
effort from each driver during covering a given distance
 Low maintenance cost.
 Eco-friendly vehicle: Causes no pollution and hence does not harm the
environment.
Contact Details
Team Members
 Ajay Kumar Valiathan
 Anand Krishnan V U (Captain)
Contact no:9486643948
E-mail ID: mekrian91@gmail.com

4.  Arjun Raja K C
 Barath V
 Narendran M
Contact no:9360527036
 Prasanna N
Contact no:9944559605
 Vignesh Kumar V
Faculty Advisor : C. Lakshmikanthan
Contact no:9943984451
Team E-mail ID : effisae.amrita@gmail.com
DESIGN REPORT
MATERIAL SELECTION
Material selection influences factors of weight, stability, safety and durability. The material for the
vehicle was decided taking the following into consideration:
o Strength
o Cost
o Availability and
o Machinability
ERW C1 is a general purpose, low carbon alloy steel. It is cost effective and has good weldability,
forming & extruding characteristics. Also, it is tough and provides excellent corrosion resistance.
Considering the above factors, ERW C1 is chosen as the material for the frame.
On a similar note, mild steel is chosen as the material for both handlebar and bottom bracket.
CHASSIS
The chassis consists of tubes for the frame,handlebar and bottom bracket. Semi-Recumbent seating
position is incorporated taking in view of its aerodynamic advantage and better driver ergonomics.
With an upright position, at speeds above 25 mph, 90% of the effort goes in overcoming wind
resistance. Tadpole layout is implemented, as it provides excellent traction, turning and braking
stability.
Tubes of 38.1 mm Outer Diameter and 1.6 mm thickness have been used for the frame.
The frame was analysed using ANSYS and the results are shown below:

5. Fig 1: Frame Analysis
FINAL DESIGN & DRIVETRAIN
Fig 2: Final Design Fig 3: Drivetrain
Description
The drivetrain allows both the riders to pedal independently of each other while also allowing the
riders to pedal alternately or simultaneously with the motor.
Implementation
The implementation of the drive train requires three freewheels. A free wheelsystem consisting of
two free wheels is placed in between the two riders cranks. The third free wheel is positioned at rear
hub (on one side). The motor is mounted close to the hub of the rear wheel with a dedicated chain
drive to the free wheel at the rear hub. Single side drivetrain is used to route the pedalling power of
both the riders to the rear wheel(on the other side).
Feasibility
The free wheel system comprising of two free wheels will be challenging to make as it will involve
some customised machining. As such the implementation of the system is feasible.
Cost Implication
The proposed drivetrain requires four chains and three freewheels. As such the drivetrain is a bit
costlier than the conventional one for a tandem electric tricycle. But the slight increase in cost
significantly improves usability and comfort.

6. BRAKES
Rim brake is chosen for all the three wheels. This is because a rim brake works equally well on any
size of wheel, as the rim's speed past the brake is nearly the same. As a rim brake operates at nearly
the full diameter of the wheel, the clamping force for a given amount of braking is much lighter than
for a hub brake and thus lowering stresses on the bicycle frame and fork. It is because the rims offer a
large heat-dissipating area; these brakes are relatively safe for speed control on long and downhill
runs. On a further comparison made between caliper and cantilever brakes (which fall under the sub
category of rim brakes), end line cantilever brake/V-brake was preferred as its mechanical
advantage is high and also, since the cantilever brakes have pivots mounted below the rims, tire
clearance can be very high.
Calculation
The stopping distance for various terrain conditions is calculated neglecting some of the resistances
using the equation
d = U2
/ (2*g (f + G))
Where,
d = Braking Distance (m)
g = Acceleration due to gravity (9.81 m/sec2
)
G = Roadway grade as a percentage;
U = Initial vehicle speed (m/sec)
f = Coefficient of friction (static) between the tires and the road
Assuming vehicle speed, U = 25 km/hr = 6.94 m/s, G= 0 (no slope) and f= 0.8, we get d= 3.068 m
Upon cross verification the value was found to be approximately the same and a graph was plotted
between braking efficiency and stopping distance.
Fig 4: Stopping distance calculator Fig 5: Effect of braking efficiency
STEERING SYSTEM
The system uses two steering tie-rods and one centrallinking member turning on an offset pivot point.
The effect of the pivot point is to provide the majority of the Ackermann Compensation. The system
utilises only four rod ends, one frame pivot and the two fork pivots. The steering uses handlebars that
extend vertically upwards in front of the seat.

7. Turning circle radius was found to be 2.87m (with an average steering angle of 20○
), by the formula
given below:
TCR = (Track/2) + (Wheelbase/ sin (Average steer angle))
SUSPENSION SYSTEM
Air suspensions perform better but are costlier. Hence a spring suspension with an oil damper is
preferred for the purpose. Here,for the tricycle, fork suspensions are used for the front wheels and
variable pitch coil spring suspension is used for the rear wheel.
The spring should not be too stiff, then it will act as a rigid link and shock will be transferred
effectively. If the spring is too loose then the shock will make a direct impact load on the frame. Both
the cases are undesirable. So an optimum stiffness is determined based on the mean load that could
possibly act on the wheel. Stiffness determines the natural frequency of the spring which will decide
the roll resistance of the spring i.e. the resistance a suspension system can offer to the load.
Natural frequency of rear suspension is given more than the front considering the weight distribution
and also to ensure a flat ride.
The spring is decided as:
 Material : Stainless steel
 No. of coils : 5
 Wire diameter : 3mm
 Outer diameter : 4 cm
Assuming total possible load to be 250 kg and the weight distribution to be 60:40 (Front: Rear)
Parameter Front wheel Rear wheel
Load (kg) 150 100
Stiffness
(N/mm)
__ 8.822
Natural
frequency (Hz)
1.3 1.5
TIRES AND WHEELS
A narrower tire has been chosen owing to its lower aerodynamic drag and lighter weight. Tubeless
tires are used for the front tires.
Material Specification
S
no:
Part Name
Material
1. Spoke (40 no.) Stainless Steel
2. Rim Aluminium

8. Dimension Specifications
S
no:
Part
Name
Wheel
Diameter
(inch)
Rim
Diameter
(mm)
Width
(mm)
1
Front
Wheel
20 406 23
2
Rear
Wheel
24 470 25
BATTERYAND MOTORSELECTION
Battery selection influences overall performance of the vehicle. The battery was selected taking the
following into consideration:
o Cost
o Weight and
o Availability
Lead Acid battery is inexpensive and requires low maintenance costs. Also, it is capable of high
discharge rates. Considering the above factors,Lead Acid Battery is chosen for the vehicle.
Battery Specifications: 12V, 26 A-h
Motor Specifications: 12V, 400W PMDC motor
The battery and motor circuit consists of the battery, a DC-DC controller and the motor.
USP
• Ideal blend of energy efficiency and cost effectiveness.
• Semi recumbent seats-more comfort and performance.
• Frame made of steel implies higher performance : cost ratio.
• The vehicle utilizes more of standard parts and hence mass manufacturing is possible. Also,
availability will not be an issue.
• No need for driving license and vehicle registration.
• Vehicle is useful for enforcement patrolling in public places like markets, airports etc.