MB1
Advisory Committee Review
April 27, 2006
Jake Adkins – Frame and Suspension
Ya-Chi Chou – Accessories/Seats
Adam Dean – Power Train
Jay Mansheim – Power Train
Saptarshi Mitra – Budget/Accessories
Eric Rodgers – Frame and Suspension
Race Day Results
 3rd Place
 Time of 5:08
 Design Competition Winners
 For best solving the problem of
navigating the lunar surface
 Most Improved Time
 First run
 Second Run
7:21
5:08
Sept
Aug
Concept Design
Oct
Nov
1
2
3
4
5
6
7
8
9
10
11
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Concept Drawings
Final Concept
Agreement
12
Dec
13
14
15
16
17
18
19
x
Component Research
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Stress Analysis
x
x
x
x
x
x
x
Component Acquisition
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Drawings
Component Fabrication
Testing
Clean up
Install Instrumentation
Instrumentation Testing
Buggy Testing
x
x
x
x
Jan
Feb
20
21
22
23
Component Research
x
x
x
x
Drawings
x
x
x
Component Acquisition
x
x
Component Fabrication
x
x
Mar
Apr
24
25
26
27
28
29
30
31
32
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
33
34
35
x
x
x
x
x
Concept Design
Concept Drawings
Final Concept Agreement
Stress Analysis
Testing
Clean up
x
Install Instrumentation
Instrumentation Testing
Buggy Testing
x
x
Budget
Funding
Source
Amount ($)
MB One Members
600
PSU
200
Electronic Systems Grant
0
Caterpillar
1600
Snorkel International
Paint
VanBecelaere Machine Works
Steel
Total
2400
TEAM
Expense Report
Grand Total
Design Conditions
 Complies with all rules set forth to
compete in the NASA competition in
Huntsville, Alabama on April 13-14,
2007.
 Weight: 80 lbs (192 lbs actual)
 Top Speed of 20 mph
 Able to handle 17” obstructions on
various types of terrain
TEAM
Design Conditions
 Reliable for a minimum of 10 miles
 Braking from 20 mph to 0 mph in 20
feet
TEAM
Safety Factor
 General 2
 Critical Weight 1.5
 High Dynamic loading (suspension)
4+
JM
Frame and Suspension
Frame (orthoscopic)
ER
Frame (top view)
ER
WaterJet files drawn in AutoCad
Shear and Moment Diagrams
ER
OPERATION WORK INSTRUCTION
Part Description
Part Number
Frame Beam, Front
101
Checked by:
AD
11/26/2006
Date:
11/26/2006
1020 HR
SFM:
120
Tooling/Fixtu
re
Tolerance
Created
by:
ER
Date:
Material:
Operation
#
1
2
Operation
Descript
ion
Cut
Material
Mill Slots
Machine
Used
Horizontal
Bandsaw
Bridgeport
Speeds,
Feeds
+/- .030
V-blocks,
3/8" End
Mill
+/-.003
1222
RPM
ER/JA
ER/JA
ER
Frame Hinge Assembly
JA
Drive Train
Design Considerations







Both riders power one output
Chain tension constant during setup
Differential
Differential Placement/Drive shafts
Usable 7 speed gear range
Quality Components/adjustment
Wheels/tires
AD/JM
Original Chain Path
ER/JM
Original Chain Path
JM/ER
Modified Chain Path
Target Gear Ratios
 High gear ratio of 2.2:1
 Low gear ratio of .8:1
 Have a useable range of gears spaced
in between to have a total of 7
speeds
AD
Gearing Options
 Option 1
 56/22/34-11/39
 Max Speed 13.8 mph @ 80 rpm
 Max torque 324 ft lbs @ 350 lbs input
 Option 2
 56/16/34-11/39
 Max Speed 18.9 mph @ 80 rpm
 Max torque 238 ft lbs @ 350 lbs input
POWER TRAIN BUDGET
Item
Bottom Bracket Case
Bottom Bracket
Plastic BB seal
Crank Set
Chainrings / Freewheels
Cage Pedal Set
7 Speed Cassette
Output Shaft/ Bearings
Derailer
Shifter / Cables
Differential
Differential Drive Gear
Universal Joints
Driveshafts
Diff. Bracket / Bearings
Chain ( 5ft )
Misc. brackets / etc.
QTY
Make/Have
Price ea.
Totals
2
2
2
2
6
2
1
1
1
1
1
1
4
2
2
4
1
0
2
0
2
0
1
0
x
0
0
1
0
0
x
2
0
x
$7
$24
$1
$30
$15
$15
$25
$10
$70
$50
$0
$15
$20
$10
$0
$25
$25
$14
$0
$2
$0
$90
$15
$25
$10
$70
$50
$0
$15
$80
$20
$0
$100
$25
Sub Total =
Wheels
Tires / Tubes (26x2.5+)
Wheel Bearings
4
4
4
0
0
0
$30
$35
$5
Sub Total =
Hydraulic Brake System
Hyd. Cable ( 8ft )
1
1
0
0
$125
$20
Sub Total =
GRAND TOTAL (Drive Train, Wheels, Brakes) =
$516
$120
$140
$20
$280
$125
$20
$145
$941
AD
Simulated Items
 Manufactured out of plastic
 Vinyl - ABS/PVC Alloy (Density: 0.6
g/cm³)
 Console, Battery box, TV box, Fender,
some simulated items will use this
material
SM/Y-CC
Problems Encountered
Failure to fit in 4x4x4 box
 Best solution would
be to be a total
redesign.
 Corrective Action:
installed a hinge on
the front pedal
tower.
Rear Upper Air bag support
brackets
 MEA (mental
element analysis)
failed.
 Corrective Action:
adding crosssectional area to
failed area
Rear A-arms
 Rear A-arms were
bent after testing
on obstacles.
 Corrective Action:
added gussets to
high stress points
on rear lower Aarms.
Driveshaft pin connection
 Pins were sheared
multiple times on
rear inboard
Universal Joints
 Corrective Action:
Welded it
 Jammed an Allen
wrench into it and
broke it off
Chain breaking
 Chain was catching
on sprocket
mounting bolts.
 Corrective Action:
countersunk bolt
heads
Back of rear seat
 Rear seat back
broke
 Corrective Action:
welded it.
Fenders
 Fender mounts failed
when bent three times
 Corrective Action:
Redesign of fender
mounts.
Problem was fixed for
the race by simply
removing the fenders.
Things we would have done
different.
 More emphasis on handlebars and
rider ergonomics.
 Try to stick closer to manufacturing
timeline.
 Limit weight
PITT
THUNDER
Questions?
Questions?