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
Team Development
• Manufacturing• Procurement• Assembly
Processes
Balsa Airframe
• Stiffening of wood airframe
Composite Reinforcement
• A-D Converter• Onboard
Memory Storage
Payload Interface
Systems Integration
Chord = 8” Span = 5’ Aspect Ratio = 7.5 AOA = 8º Camber = 8.6% Thickness = 10.125% Lift = 10 lbf
Main Airfoil Data
9.1
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252
1 2
l
l
l
c
Mfc
spanchordS
mphu
ScuL
Chord = 6.2” Span = 25.375” Aspect Ratio = 4.093 AOA = 8º Camber = 0% Thickness = 12% Lift = 1.7 lbf
Tail Airfoil Data
Getting parts into ANSYS
1. Airframe saved as .STP file in TurboCAD2. File of the entire airframe assembly is
imported into Pro/E3. Sub-assemblies are saved as .IGS files4. In ANSYS an .IGS file is imported
Free Body Diagram of Wing
5lb 5lb
10lby
x
Balsa Material Properties
•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
Observation Evaluation Recommendation
Laser cut parts were processed to tighter tolerances than anticipated
All placement notches on jigs were modified via manual sanding
Redesign jigs to accommodate larger placement notches
Cyanoacrylate (CA) adhesive was more effective in balsa joints than ply joints
Absorption and cure times increase for plywood applications
Research alternative adhesive or ply material
Manufacturing Process Discoveries
Manufacturing Process Discoveries (cont)
Observation Evaluation Recommendation
Similar laser cut parts are not easily distinguishable
Limited etching prevented inexperienced builder identifying parts
Assign part number under each sub-assembly in BOM and laser etch each 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
Manufacturing Process Discoveries (cont)
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
Batteries-Lithium Polymer chosen for high energy density-Modular System-Single pack, ~10min Flight time
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00$0.00
$50.00
$100.00
$150.00
$200.00
$250.00
$300.00
$350.00
$400.00
$450.00
Battery Price vs. Flight Time
LiPo2x LiPoNiMH
Flight Time @50W/lb (Minutes)Pr
ice (U
S Do
llars
)
Power Distribution-COTS Switching regulator converts
Battery / Motor voltage to 5v- 12.5W minimum available from the
BEC for additional onboard electronics
TelemetryReal Time
- Altitude / Airspeed-Temperature - Servo Voltage/Position Data- GPS
Two additional onboard ADCs for future sensor testing.
Control SwitchingEnables 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 flightsWorking prototype. PCB design has begun. Design Review 2/13/09
~$50 total per system.
Expense Sheet 1/19/2009 $ 276.18 Tower Hobbies, remaining mat
$ 93.00 ACP-Composites
$ 18.00 Digikey, control switch
1/28/2009 $ 75.20 National Balsa1/29/2009 $ 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
Total As Of 2/10/2009 $ 1,414.23
Airframe A Segregated Budget
Raw Airframe with motor Component Qty Piece Price Total PriceMotor HXT42-60 1 $ 35.79 $ 35.79 Landing Gear 1 $ 25.27 $ 25.27 Linkages, Connectors, Hinges, misc 1 $ 50.00 $ 50.00 Balsa Stick, Sheet 1 $ 16.50 $ 16.50 Laser-Cut Balsa 1 $ 25.00 $ 25.00 Propeller 1 $ 1.00 $ 1.00 Covering 1 $ 5.00 $ 5.00 Composite Material 1 $ 5.00 $ 5.00
Subtotal $ 163.56 ElectronicsServo S3010 2 $ 19.99 $ 39.98 Receiver Supreme 28 LXKYK3 1 $ 39.99 $ 39.99 Servo S3114 2 $ 14.99 $ 29.98 Speed Controller 1 $ 16.79 $ 16.79 Battery eliminator circuit 1 $ 19.95 $ 19.95
Subtotal $ 146.69
Airframe without batt $ 310.25
BatteryLithium Polymer 2 $ 19.99 $ 39.98 Telemetry (Optional) 1 $ 627.97 $ 627.97
Total $ 350.23 w/Telemetry $ 978.20