Transcript Design Morphology

2010 SAE Mini Baja Competition
Suspension
Frame
Drive Train
Cody Dykman
Jesse Ramer
Jesson Salyards
Warren Starbuck
Brett Schuler
Doug Romoth
Josh Voorhees
Corey Saner
Spencer Garland
Kyle Werkele
Our goal was to design, test, and
manufacture a safe, light weight, and rigid
off road baja car that would withstand a
series of rigorous off road tests. This
included components of the frame, drive
train, and suspension of the vehicle.
• Single Passenger
• 10 hp Briggs & Stratton Engine
• SAE Rules and Regulations
• Goal:
-12 inches ground clearance under
vehicle weight
-10 inches suspension travel
-14 foot turning radius
-Withstand rollover to 30 degrees
Springs and Dampers:
• Gas/oil Springs
-Nitrogen over oil design integrates spring
rate and damping coefficient in one
compact unit
-Spring rate and damping coefficients
adjustable over a wide range of values
-Readily available and low cost
Front End Design:
• Unequal length double A-arms
-Excellent axial and lateral strength
-Easily adjustable
-Provide constant point of contact
between tire and ground (eliminates
bump steer)
Rear End Design:
• Laterally supported trailing arm
-High strength with 3 lightweight members
-Easily adjustable
-Eliminates Driveshaft Plunge
• Shocks/Springs
-Gas
-Coil Over
-Torsion Bars
• Suspension Components
-Double A-arm
-Single A-arm
-Trailing Arm
-Integrated Trailing Arm
• Achieved:
-12 inches ground clearance under
vehicle weight
-12 inches suspension travel
-15.8 foot turning radius (without cutting brakes)
-9.2 foot turning radius (with cutting brakes)
-Withstands rollover to 43 degrees
• Protect the driver
• Accommodate suspension and drive train
components
• No continuous tubing with multi-plane bends
• Less than 450 total weight
• Comply with all SAE Rules
• Material Type
-Aluminum
-Composites
-Steel
• Tubing
-Square
-Round
•
Construction Methods
-MIG
-Oxy-Acetylene
-TIG
Frame
Red Members
• Specified By SAE
• 1” OD, 18% Carbon
• 0.12” Wall Thickness
• Or Equivalent
Strength and
Stiffness
Blue Members
• Specified By SAE
• 1” OD
• 0.035” Wall
Thickness
Frame Tubing
Bending Strength of 1018 and 4130 Tubing
Bending Strength (Lb /in)
14,000
1", 1018
1.125' 1018
12,000
1.125", 1018
10,000
1", 4130
8,000
1.125", 4130
6,000
1.25", 4130
4,000
Min Wall Thickness
2,000
0.06
0.07
0.08
0.09
0.1
0.11
0.12
0.13
Minimum Bending
Strength
Wall Thickness (in)
Bending Strength
Bending Stiffness=E*I
Frame Tubing
Weight of Select Tubing
2.35
Weight per foot (lb/ft)
2.15
1.95
1"
1.75
1.125"
1.55
1.25"
1.375"
1.35
1.5"
1.15
0.95
0.75
0.06
0.07
0.08
0.09
0.1
0.11
0.12
0.13
0.14
0.15
0.16
Wall Thickness (in)
Selected Tubing 4130 Steel
1.25” Outside Diameter
0.065 Wall Thickness
Frame Model
Visual Analysis
Drew Model and
Specified
Properties of Members
•Applied Loads
•Forces and Moments
•Deflection In Members
•Stress in Members
Fabrication
Bent Tube
Construction
Notched Tubing
TIG Welded
Tubing Frame Weight
75 lbs
• Goals
-Maximum speed~ 25 mph
-Drive train weight ~ 60 lbf
-2 rotating shafts
•
•
No load engine rpm = 3800
Loaded engine rpm = 3030
-Due to efficiencies of the CVT, planetary gear
reduction, and bearings
•
Max speed of 21.3 mph
-Tire Diameter = 25 in.
-Differential rpm ≈ 287
Engine to Differential Gear Reduction = 56.8:1
(engagement) to 10.6:1 (top speed)
• CVT Reduction
-Maximum Reduction: 3.71:1 (engagement)
-Minimum Reduction: 0.69:1 (top speed)
• After CVT Reduction = 15.5:1
-Through Planetary = 5:1
-Sprocket to Differential = 3.1:1
Design (1st Stage):
Continuously Variable Transmission
-Primary Clutch
-Secondary Clutch
-Belt
Design (2nd Stage):
Planetary Gear Reduction
Annulus
Planet gear
Sun gear
Planetary gear fixture
Design (3rd Stage):
Sprocket to Differential Reduction
-Drive Sprocket
-Driven Sprocket (Differential)
-Chain
Design (4th Stage):
Drive Shafts
-U Joints
-Drive Shafts
-CV Joints
• CVT with a planetary reduction and a single chain drive
gear reduction
• CVT with single stage direct gear mesh
• CVT with double stage direct gear mesh
• Hydraulic system
Achieved
-21 mph
-67 lbs
-2 rotating shafts
Schedule
Registration
$ 1,000.00
Frame
$ 1,215.66
Suspension
$ 943.97
Drive Train
$ 914.66
Travel
$ 4,205.36
Total
$ 8,279.65
• 2010 SAE Mini Baja Car Competition was
held in South Carolina April 8th -11th
• 3 Static Events:
-Design Report
-Evaluation
-Cost Report
• 5 Dynamic Events:
-Acceleration
-Pulling
-Maneuverability
-Suspension
-Endurance
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•
•
•
•
Machined Sprockets
Multispeed Transmission
Coil Over Shocks
Shorter Wheelbase
Narrower Track Width
Cowboy Racing would like to give a special
thanks to:
•
•
•
•
2009 UWYO SAE Mini Baja Team
NAPA
Uniwyo Federal Credit Union
Allen Canete
• Engineering Advisors:
-Dr. Paul Dellenback
-Mr. Scott Morton
Thank You for your time.
Questions? Please ask them now.