Virtual BAJA 2013
Team Meccano United College of Engineering & Research Allahabad
Our Methodology
Month
Project plan Revise Market Survey Research Design outline Design Analysis & simulatio n Calibrati on Ppt & report Virtual event Market survey Fabricate Test
Oct
Nov
Jan
Feb
Mar
Apr
Jun
Jul
Aug
Sep
Oct
Nov
Jan
Feb
Roll Cage •
• • •
Synced with the rulebook Simple , light weight, low cost, safe and robust in design. Easy to manufacture . Various bends reduces no. of welds wherever possible. 1018 steel 1’’ x.12’’
1020 DOM 1.25”x.06 5”
4130 1.25”x.06 5”
365 Mpa
539 Mpa
3640 Mpa
Bending stiffness
2790 Nm2
3640 Nm2
3640 Nm2
Bending strength
391 Nm
602 Nm
747 Nm
Weight/100’
50 kg
37 kg
37 kg
Overall length 107 inch Track width
63 inch(front) 58 inch(rear)
Material
1020 DOM steel
Yield strength
Analysis of Roll Cage
Total Deformation(Front impact)
• Tested chassis assuming head on collision with another vehicle at speed of 50 km/h. • Full load considered on the tow hitch point. • Bending took place but, maximum bending at hitch point and SIM only.
Total Deformation(Rear impact) • Assumed vehicle getting hit by a vehicle moving at 50 km/h. • Maximum bending on the rear portion only of 5 cm. • Driver remains safe..
Double Wishbone Suspension
Independent shock absorption. The suspension system is easy to work out the effect of moving each joint, so the kinematics of the suspension can be tuned easily and wheel motion can be optimized. It always maintains the wheels perpendicular to the road surface irrespective of the wheel movement. It increases negative camber thus increasing control.
A-arm
Length
Performance criteria
Value
Top
13.5”
Caster
9 degree
Bottom
12.7”
Camber
-2 degree
Top Material
1020 DOM
Rate of camber change
.3125 of camber/1 of bottom arm rotation
Bottom material
1020 DOM
Distance from center to COM
8”
Steering System
We have chosen this design due to its simplicity and robustness. For steering we have used simple rack and pinion design. The steering is designed to go for more than 100% Ackerman which decreases the driver input to the wheel and the steering response becomes much smoother. Our decision matrix gives us a good reason to opt such system.
Hydraulic system
Rotary cable
Rack & pinion
Feedback
5
4
3
Ease of operation
5
3
4
Maintenance
1
3
4
Cost
1
2
5
Total
12
12
16
Brake system
For brake system designing, the prime importance was given to the simplicity. We decided to use two pairs of hydraulic disc brakes that are best suited to the vehicle. Disc brakes are suitable as it have comparatively better anti-fade characteristics. Each hydraulic brakes act on all wheels and is operated by a single foot as per the rules.
Engine & Wheel Engine
Briggs and Stratton OHV
Company
Pitbull
HP
10 HP
Dimension(Front) 25.5”x 8”
Torque
19 Nm
Dimension(Rear)
25.5”x 10”
Bore
79 mm
Price
Stroke
61 mm
Rs 63000 (each)
Power Train
CVT allows our engine to constantly run near its maximum torque, it would give us the ability to get max power from the engine in both the high and low ranges.
Transmission decision matrix
Operating the CVT is easier for the driver. CVT is designed to have infinite gear ratios between its high and low range. CVT consists of the primary spring, cam weights, secondary springs, and secondary cam. These four parameters control nearly every aspect of the transmission such as engagement rpm, shift speed, acceleration rpm, belt grip, up shifting, back shifting, and many others.
Parameter
CVT
MT
Weight
1
0
Performance
1
1
Drivability
0
1
Reliability
0
1
Tuning
1
0
Simplicity
1
0
Ease of installation
1
0
Total
5
3
Body panel
Aluminum sheet is easy to work and mold in any shape easily. We chose to use 14 Gauge 5052 Aluminum sheet for all body panels. A firewall to keep the driver safe from any power-train fires and failures. This firewall is going to be constructed out of 23 gauge Aluminum sheet.. A skid plate on the bottom of the cockpit. Eighteen gauge aluminum sheet was chosen for the skid plate because of its strength and light weight.
Electrical system
Two easily accessible kill switches are installed on our vehicle to provide an easy and safe way to kill the motor by both the driver and somebody assisting the driver. 2 head lamps. A brake/reverse light when the brakes and reverse gear are engaged. Horn and reverse buzzer. Indicator and speedometer installed on the dash board. Battery with 12V/44 Ah as power source located behind firewall.
HUMAN ERGONOMICS
• Driver Clearance • 9” above helmet • Torso, knee, shoulder, elbow, hand, arms have at least 3” clearance. • Easy reach to various accessories rope starter, switches, fire extinguisher, etc. • Sufficient large space providing easy escape in case of emergency. • Rally seat is to be installed due to its safety based design and comfort. • Comfortable orientation of steering system and paddles.
Safety
Installation of a 5 point harness. A fire extinguisher mounted on the left hand side RRH of the cockpit. A gas tank splash shield. Robust structure of roll cage. Sufficient space for exit of driver from car in case of emergency. Firewall of thickness 18 Gauge aluminum sheet to be used for the safety of the driver. Various safety gadgets like helmet, driving jacket, neck support, goggles will add up the extra safety to the driver.
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