RC Airplane
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Transcript of RC Airplane
Table of Contents Timeline Gantt Chart Problem Statement Background Customer Scope Customer Requirements Deliverables Brainstorming Research Identify Criteria & Constraints Explore Possibilities Pros and Cons Select an Approach CAD Bill of Material Build Process Test Criteria Test Plan Prototype Test Results Lessons Learned Summary
Problem Statement
Students lack proficiency in Engineering
By creating an RC airplane: Gain knowledge Gain experience for college environment
Background
Gain knowledge in Aeronautics and Material Sciences
Implement calculus and physics for advanced calculations
Recognize properties of different materials – balsa wood, foam, etc.
Scope
Create RC airplane to takeoff, fly, and land
Consist of fuselage, wings, motor, servos
Documented in engineering notebook Presented in technical report and
Powerpoint presentation
Scope (cont’d)
Experts Mr. Pritchard Mrs. Brandner Mr. Cotie
Built of balsa wood and foam Held together with various glues Create lightest prototype as possible
Scope (cont’d)
Requirements 12-step design process Strength tests Cost estimates CAD drawings Data for 3 diff. materials Calculations for plane (thrust, drag, lift)
Customer Requirements Mr. Pritchard
3 tests on 3 different materials Strength test on material/prototype
Mrs. Brandner Complex calculations using physics and calculus Submit engineering notebook
Additional Must fit in technology room Must be tested outside school property
Deliverables
Mr. Pritchard RC Airplane prototype Final Report Design Notebook(s) Powerpoint Presentation
Mrs. Brandner Calculations
Brainstorming
Construction What building materials will be used? What bonding materials will be used? What prefabricated materials will be
used? What tools will be used?
Brainstorming (cont’d)
Plane characteristics How will the airplane be powered? How will the airplane be maneuvered? What weather conditions are required to
fly the plane? What wing structure will be used? What aesthetics will we consider? What is the optimal center of gravity?
Brainstorming (cont’d)
Testing Where will we fly the airplane? What if the airplane crashes? Will we need permission to fly the
airplane? How will we test the airplane?
Research
Looked heavily into materials Balsa vs. Basswood Foam vs. Metal vs. Fiberglass
Structure of plane Skeleton build with thin covering Solid build
Research (cont’d)
Motor types Electric, nitro engine, jet engine
Servos Move surfaces of plane Provide turning capabilities
Propeller/Landing gear Propeller needs to fit with motor Proper size wheels
Research (cont’d)
Plane channels Ailerons for roll Elevators for pitch Throttle for speed Rudder for yaw Electronic Speed Controller (ESC) 3-channel system most practical
Research (cont’d)
Wing position High, mid, and low-wing High is most stable and easiest to fly
Tail V-tail and T-tail T-tails better with low speeds for control
Transmitter Prefabricated at 72 MHz frequency band
Identify Criteria & Constraints
Criteria Applications of Calculus
Calculations for d(t), v(t), a(t) Calculations for lift force Calculations for engine torque Calculations for thrust Calculations for types of materials Optimization with different materials and
structures Submit engineering notebooks
Identify Criteria & Constraints Criteria
Applications of Technology Application of the 12 step design process
Testing procedures for different types of materials and their strengths
Submit final report and Power Point
Submit airplane prototype
Submit CAD drawings
Identify Criteria & Constraints
Criteria Control Panels Flying tests must be outside school
property
Constraints Must fit inside technology room 3 ft. wingspan for detail, but not too
large
Pros and ConsMaterials Pros ConsBalsa wood Porous
Less glue required Lightweight Cheap Widely available Stiff Easy to sand
Varying strength
Basswood Won’t crush Lightweight
Hard to sand Not widely available More expensive
Foam Very lightweight Hard to work with Not very strong
Plastic Strong Rigid
Rigid Hard to work with Expensive Relatively heavy
Metal Very strong Rigid
Very heavy Expensive Hard to work with Not widely available
Fiberglass Very strong Very lightweight
Very expensive No previous experience Not widely available
Pros and Cons (cont’d)
T-tail best choice Aerodynamics Cleaner airflow
Tails Pros ConsV-Tail Lightweight
Less drag Sturdy
Less aerodynamic
T-Tail Keep airflow behind wing Creates clean airflow Better pitch control
Can break at landing
Pros and Cons (cont’d)
High wing best choice Easiest to fly/build Stable Makes sustained flight easiest to attain Acrobatics not necessary
Wings Pros ConsHigh wing Most stable
Easiest to fly Easy to build
Not as acrobatic
Low wing Easy to roll Hard to fly Top-heavy
Mid-wing Easy to turn Hardest to fly Wings at bulk of mass
Pros and Cons (cont’d)Adhesives Pros ConsWood Glue (Urea) Easiest to use
Low cost Light color
Poor heat resistance Poor moisture resistance Bond not very strong
Hot Glue Quick cooling time Relatively easy to use Low cost
Bond not strong Leaves residue Visible on plane
Gorilla Glue Very light Expands while setting Best for wood than other
materials Waterproof
Hard to work with Contains air bubbles Somewhat expensive
Pro-bond Glue Expands when dry Less glue required Cheap Water-resistant
Heavy
Rubber Cement Strong flexible bond Easy to peel off Not brittle
Flammable Highly toxic Expensive
Super Glue Very strong bond Often used for model aircraft Versatile Water resistant
Expensive Can become brittle Long cure times
Pros and Cons (cont’d)
Propellers Pros Cons
Dual Blade Easily available Very efficient Easy to use Fairly cheap
Larger diameter
Multi Blade Smaller diameter Less available Less efficient
Wood Blade Very rigid Efficient Light
Breaks easily
APC Blade (Metal) Don’t break as easily Efficient
Heavy
Pros and Cons (cont’d)Motors Pros ConsElectric Cheap
Easy to run Clean Doesn’t require gasoline Lightweight
Low power / torque
Nitro Relatively cheap Wide availability High torque and power
Special mixture of fuel Heavy
Gas High torque and power Not as available Heavy Special mixture of fuel Expensive
Jet Extreme power Extremely expensive Not as available
Bill of MaterialPART PART DESCRIPTION COST PER UNIT QUANTITY TOTAL COST
Power 15 Brushless Outrunner Motor
950 Kv, 575 Watts $79.99 1 $79.99
3-channel controller Hitec Neon SS 72 MHz
$67.99 1 $67.99
Landing Gear Elite Mini UltraStick $12.95 1 $12.95
Servos HS-311 6.0 Volt $11.99 2 $23.98
Carbon fiber tube 0.210” outer diam. x 0.132” inner diam. x 40”
$7.99 1 $7.99
EPS Foam ¾” x 14 ½” x 48” $9.49 1 $9.49
Propeller Speed 400, 5.25 x 6.25 $2.13 1 $2.13
Pushrods Fiberglass $8.95 2 $17.90
Balsa Wood ¼” x 36” $0.89 2 $1.78
TOTAL COST $224.20
Build Process
Part A Layer four sheets of EPS foam on top of each
other. Use four very thin dowel rods or four vise grips
and stick it through all four layers in each of the four corners of the stack in order to hold it in place.
Using a Sharpie, mark a rectangle that is 4” x 23” on the top of the stack.
Using a hot wire, carve out the resulting box.
Remove the cut out pieces. Clamp these four pieces together so that all of the
edges are flush. Using a box cutter, shave out the shape of the
fuselage. Remove the vise grips and glue the four sheets
together. Sand Part A so that it is smooth.
Build Process (cont’d)
Build Process (cont’d)
Part B Obtain one sheet of EPS foam. Using a Sharpie, trace the side of Part B on the
end of the foam sheet. Using a hot wire, trace this line and cut out the
shape of Part B.
Test Criteria
Test Criteria for Prototype Safety Functionality (in air/on ground) Ease of use Aerodynamics Velocity Weight/Size Strength
Test Criteria
Test Criteria for Materials Foam
Strength Safety Compression/Tension Flexibility Weatherability (ability to withstand outdoor
conditions)
Test Criteria Test Criteria for Materials
Adhesive Weatherability Holding strength Drying time
Motor/Propeller Thrust Torque Voltage (if necessary) Weatherability Weight/Size Functionality
Test PlanTest Criteria How Tested Expected results Actual Results
Overall Plane Aerodynamics Look at the overall body of the plane and determine if any parts of the plane will decrease aerodynamics.
The plane will have sound aerodynamics and will have minimal drag.
Functionality Move all surfaces (rudder, elevators) and check for responsiveness.
All motorized parts of the plan will respond well.
Safety Check if the plane flies consistently in the air and doesn’t wobble.
The plane will be safe and won’t wobble.
Strength Hang weights on the wings and see if the flex too much or break. Put weights on other critical structures of the plane.
The plane will be able to support the weight and will not fracture.
Velocity While in the air, look at distance/time to determine the speed.
The velocity will be high enough to sustain flight.
Weight/Size Measure the overall plane’s dimensions. Put the whole plane on a scale.
Plane’s weight will be in proportion to its size.