P09231
MSD I Winter 20082






Matt Greco: Project Manager
Shawn O’Neil: Lead Engineer
Will Pisarello: Electrical Systems Engineer
Phil Davenport: Industrial/Process Engineer
Brian Lindquist: Industrial Engineer/Procurement
Specialist
Eric Lannan: Airframe Structural engineer
•Manufacturing
•Procurement
•Assembly
Processes
Balsa Airframe
Composite
Reinforcement
•Stiffening of wood
airframe
•Surfaces
•Propulsion
•Linkages
•Communication
Control System
Data
Acquisition
•Onboard telemetry
•Control System
Monitoring
•GPS Positioning
•A-D Converter
•Onboard Memory
Storage
Payload
Interface







Chord = 8”
Span = 5’
Aspect Ratio = 7.5
AOA = 8º
Camber = 8.6%
Thickness = 10.125%
Lift = 10 lbf
1 2
L  u Scl
2
u  25mph
S  chord  span
cl  f ( M  , Re,  )
cl  1.9







Chord = 6.2”
Span = 25.375”
Aspect Ratio = 4.093
AOA = 8º
Camber = 0%
Thickness = 12%
Lift = 1.7 lbf
1.
2.
3.
4.
Airframe saved as .STP file in TurboCAD
File of the entire airframe assembly is imported
into Pro/E
Sub-assemblies are saved as .IGS files
In ANSYS an .IGS file is imported
Balsa Material Properties
5lb
•Young’s modulus
1130 – 6000 Mpa
•Shear modulus
100 - 500 MPa
•Tensile strength
0 - 75 MPa
•Compressive strength
3.5 - 27 Mpa
Material properties from Matbase.com.
http://www.matbase.com/material/wood/
class4-5-10-years/balsa/properties
y
5lb
10lb
x
Observation
Evaluation
Recommendation
Laser cut parts were
processed to tighter
tolerances than
anticipated
All placement notches on
jigs were modified via
manual sanding
Cyanoacrylate (CA)
adhesive was more
effective in balsa joints
than ply joints
Absorption and cure times
Research alternative
increase for plywood
adhesive or ply material
applications
Redesign jigs to
accommodate larger
placement notches
Observation
Evaluation
Recommendation
Similar laser cut parts are
not easily distinguishable
Assign part number under
Limited etching prevented
each sub-assembly in
inexperienced builder
BOM and laser etch each
identifying parts
raw piece
Alignment of dihedral
braces is very difficult
The braces are inherently
angled, making for
difficult alignment
Etch alignment lines on
each brace for quick visual
alignment with wing box
Observation
Evaluation
Recommendation
Formers along fuselage
require exact alignment
prior to application of
stringers
Formers must be
positioned in 3D space,
leading to error in first
plane
Design a jig for ease of
former placement
Battery hatch did not
assemble as designed
Clearance for hatch
decreased during
assembly of stringers
Place block to maintain
battery compartment
shape during stringer
assembly
Battery Price vs. Flight Time
$450.00
$400.00
-Lithium
Polymer chosen
for high energy density
-Modular System
-Single pack, ~10min Flight
time
Price (US Dollars)
$350.00
$300.00
$250.00
LiPo
$200.00
2x LiPo
$150.00
NiMH
$100.00
$50.00
$0.00
0.00
5.00
10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00
Flight Time @50W/lb (Minutes)
-COTS
Switching regulator converts
Battery / Motor voltage to 5v
- 12.5W minimum available from the BEC for
additional onboard electronics
Real Time
- Altitude / Airspeed
-Temperature
- Servo Voltage/Position Data
- GPS
Two additional onboard ADCs for future sensor testing.
Enables onboard control switching between two pilots or a single
pilot and an autonomous system
Uses:
- Autonomous system testing with pilot backup
- Control ‘hand off’ between pilots a significant distance apart for
extended range flights
Working prototype. PCB design has begun. Design Review 2/13/09
~$50 total per system.
1/19/2009 $
Airframe A
276.18 Tower Hobbies, remaining mat
Segregated Budget
Raw Airframe with motor
Component
Motor HXT42-60
Landing Gear
Linkages, Connectors, Hinges, misc
Balsa Stick, Sheet
Laser-Cut Balsa
Propeller
Covering
Composite Material
Qty
Piece Price
Total Price
1$
35.79 $ 35.79
1$
25.27 $ 25.27
1$
50.00 $ 50.00
1$
16.50 $ 16.50
1$
25.00 $ 25.00
1$
1.00 $
1.00
1$
5.00 $
5.00
1$
5.00 $
5.00
Subtotal
$ 163.56
Electronics
Servo S3010
Receiver Supreme 28 LXKYK3
Servo S3114
Speed Controller
Battery eliminator circuit
2
1
2
1
1
$
$
$
$
$
19.99
39.99
14.99
16.79
19.95
Subtotal
Airframe without batt
$
$
$
$
$
$
$
93.00 ACP-Composites
$
18.00 Digikey, control switch
1/28/2009 $
1/29/2009 $
75.20 National Balsa
104.76 HobbyKing, 4 batts
$
93.30 HobbyKing, electronics
$
50.00 FoxLite, laser cutting
2/6/2009 $
$
66.05 Performance Hobbies, misc
9.77 Home Depot
39.98
39.99
29.98
16.79
19.95
146.69
$ 310.25
Battery
Lithium Polymer
Telemetry (Optional)
2$
1$
19.99 $ 39.98
627.97 $ 627.97
Total
w/Telemetry
$ 350.23
$ 978.20
Total As Of
2/10/2009 $
1,414.23