R/C Sports Aircraft from Scratch

by Weiss, Alex

• ISBN13: 9781854861405
• ISBN10: 1854861409
• Format: Paperback
• Copyright: 2002-01-01
• Publisher: Specialist Interest Model Books ltd

Summary

A comprehensive book which deals with detail with every imaginable aspect associated with the design and construction of powered sports models, this book covers everything from material to aerofoil selectio, monoplanes to offbeat aircraft, wheel to ski size and the decision of what to build, to the first flight. It is lavishly illustrated with photographs, detailed line drawings, useful tables and informative graphs.

Table of Contents

Introduction
The aim of the book	xi
Avoiding maths	xii
Acknowledgments	xiii
Getting Going
Why build from scratch?	1	(1)
Deciding what you want	1	(2)
How difficult is it?
The aesthetics
What is a 'sports' model?
Knowing your limitations
Flying field considerations
Number of channels
Modifying existing designs	3	(1)
Sketching on plans
Using components from current/crashed models	4	(2)
Changing the size of proven designs	6	(1)
What to build	6	(4)
Low wing layouts
High wing configurations
Other wing positions
A three view sketch
Propeller ground clearance and aircraft rotation
Sports scale	10	(3)
Sources of scale information
Compromises and simplification
Choosing a Configuration
Conventional layouts	13	(1)
Monoplanes
Biplanes
Offbeat aircraft	14	(2)
Flying wings
Deltas
Canards
Engine location	16	(2)
Multi engines
Undercarriages	18	(3)
Noselegs versus tail draggers
A Suitable Size
Transportability	21	(7)
Choosing the dimensions
Wingspan and aspect ratio
Fuselage length and cross section
Tail size and position
All moving tails
Fin size
V or butterfly tails
Balancing the model	28	(4)
Centre of gravity location
The aerodynamic mean chord (AMC)
Biplane and canard centres of gravity
Effect of size on flight performance	32	(1)
Providing Power
Possible sources of power	33	(3)
Two stroke glow engines
Four stroke glow engines
Diesels
Petrol engines
Silencers
Installing I/C engines	36	(4)
Upright, inverted or sidewinder
45° mounting
Pushers
Pylon mounting
Slot propellers
Engine bearers and plates
Plastic and metal engine mounts
Fuel systems
Propellers
Electric Power	40	(3)
Motors
Batteries
Folding propellers
Installing electric motors	43	(2)
Defeating Drag
The basic facts	45	(1)
Drag	45	(3)
Parasite drag
Form drag
Interference drag
Skin friction
The boundary layer
Laminar boundary layer
Turbulent boundary layer
Transition point
Factors affecting parasite drag
Air speed
Shape
Interference drag
Surface area and smoothness
Induced drag
Factors affecting induced drag
Total drag
Variation of drag with speed
Speed for minimum total drag
Speed and speed range	48	(3)
Thrust
Speed range
Lots of Lovely Lift
Generating lift	51	(1)
Types of aerofoil	51	(3)
High
lift aerofoils
General purpose aerofoils
High-speed aerofoils
Centre of pressure
Movement of the centre of pressure
Amounts of lift
variation of lift with angle of attack
Stalling angle of attack
Variation of drag with angel of attack
Variation of lift/drag ratio with angle of attack
Aerofoil sections	54	(6)
Aerofoils
Symmetrical aerofoils
Flat plate
NACA 0009
NACA 0018
Semi-symmetrical aerofoils
NACA 2412 and 2415
Eppler 374
Other cambered aerofoils
Curved plate
Clark Y
Gottingen 797
NACA 6412
NACA 2R212 Reflex
Your own special aerofoil
Wing planform	60	(7)
Wing vortices
Aspect ratio
Aspect ratio and induced drag
Aspect ratio, lift and stalling
Use of high aspect ratio
Sweep-back
Effect of sweep-back on lift and drag
Tip-stalling, aileron response and pitch up
Alleviating tip-stalling
Pros and cons of various planforms
Wing position	67	(1)
Dihedral and anhedral
Wing loading	68	(1)
High-lift devices	68	(5)
Flaps
Types of flaps
Simple flaps
Split flaps
Fowler flaps
Slats and slots
Control Characteristics
Maneouvrability	73	(2)
Aerobatic capability
Speed
Payload
Take-off and landing characteristics
Flight duration
Stability	75	(8)
The three axes
Longitudinal axis
Directional axis
Lateral axis
Static and dynamic stability
Static stability
Dynamic stability
Subsidence and divergence
Longitudinal stability
Position of the centre of pressure
Angle of attack
Wing loading
Looping accelerations
Turbulence
Transient disturbances
Degrees of longitudinal stability
Too stable
Not stable enough
Unstable
Desing of the tailplane
Lateral and directional stability
Lateral stability
Positive lateral stability
Negative lateral stability
Neutral lateral stability
Dihedral angle
Sweep-back
High keel surface
High wing and low centre of gravity
Directional stability
Directional stability and the spin
Interaction between lateral and directional stability
Spiral instability
Oscillatory instability
Roll with yaw
Degrees of stability
Automatic stability
Trim	83	(3)
Wing and tail incidences
Wing incidence
Tailplane aerofoils
Downwash
Longitudinal dihedral
Engine thrust lines
Up/down thrust
Side thrust
Control surfaces	86	(8)
Effectiveness
Elevators
Ailerons
Inset ailerons
Adverse yaw and aileron drag
Strip ailerons
Spoilers as ailerons
Aileron reversal
Rudders
Options for avoiding elevator/rudder contact
coupled aileron and rudder
Elevons
Ruddegators and flaperons
Airbrakes
Balancing
Mass balancing
Aerodynamic balancing
Overbalance
All moving tails
Moving control surfaces
Flutter	94	(5)
Torsional flexural flutter
Torsional aileron flutter
Flexural aileron flutter
Elevator and rudder flutter
Making the most of Materials
The basic materials	99	(3)
Choosing the size of material
Balsa
Obechi
Liteply
Ply
Spruce
Beech
Cardboard
The Plastics	102	(5)
Foam
Foam board
Plastics and vacuum forming
ABS
Acetate
Acrylic
Polycarbonate
PVC
Styrene
Other plastics
Expanded Polystyrene
Polyester
Polycarbonate
Glass reinforced plastic
Designing in strength
Estimating moulding thickness
Estimating weight
Strength
Exotic materials
Metals	107	(1)
Aluminium alloy
Piano wire
Brass
The Choice of adhesives	108	(2)
Building in lightness	110	(1)
The Stress points
Airframe Alternatives
The fuselage	111	(1)
Formers	111	(1)
Simple boxes	111	(2)
All sheet
Open frame
Oval and circular shapes	113	(1)
Horizontal and vertical crutches
Stringers
Sheeted
Planked
Rolled tubes
Advanced shapes and materials	114	(1)
Metal
GRP and wooden cowls
Wings	115	(2)
Parallel chord
Tapered
Elliptical
Wing tips
Biplanes and triplanes
Multi engined aircraft
Aerofoils	117	(2)
Flat plates
Curved plates
Flat bottomed aerofoils
Symmetrical and semi-symmetrical aerofoils
Under cambered aerofoils
Washout
Wing construction	119	(5)
Leading and trailing edges
Spars
Ribs thickness and spacing
Capping strips
Sheeting
Foam wings
Cut-outs in foam wings
Joining wing panels
Sweep-back
Attachment of wings to the fuselage	124	(2)
Cabane struts
Wing struts and rigging
Tailplanes and fins	126	(2)
All sheet
Built up
Sheet cored
Foam
V or butterfly tails
Attachment to the fuselage
Types of undercarriage	128	(2)
Fixed
Sprung
Retracts	130	(1)
Retraction mechanism
Mounting
Wheel wells
Undercarriage doors
Tricycle or tail dragger	130	(1)
Noselegs
Tail draggers
Wheels	131	(1)
Wheel spats
Installation	132	(1)
Operating off water	133	(2)
Floats
Seaplanes
Wing tip floats
Operating off snow	135	(2)
Control Configurations
Primary controls	137	(5)
Elevators
Ailerons
Aileron hinges
Differential and Frise ailerons
Spoilers as ailerons
Elevons
Rudders
All moving tails
Airbrakes
Simple and split flaps
Hinging	142	(1)
The radio equipment	142	(1)
Planning the Installation
Number and positioning of servos
Control runs	143	(4)
Push rods
Bell cranks
Snakes
Closed loop controls
Horns
Clevises
All moving tails
Final Finishing Off
Cockpits	147	(1)
Canopies
Open cockpits
Pilots
Hatches	148	(1)
Stores	148	(1)
Types of covering	149	(1)
Tissue
Nylon
Heat shrink fabric and film
Glass skinning
Painting	150	(3)
Decoration
Fuel-proofing
Drawing the Design
Manual methods	153	(1)
Making copies
Drawing instruments
Drawing boards
Computer Aided Drawing (CAD)	154	(1)
Detailed Design	154	(3)
Indicating different materials
Drawing aerofoils
Transferring the information
Getting it published	157	(2)
The First Flight
Before the first flight	159	(3)
Balance
Rigging
Checking the weight
Control throws
The use of rates
Choosing the Propeller
Taxying trials
The Video
A first hop
The first flight	162	(2)
Flaps on take-off and landing
Raising flaps in flight
Controllability
Stall characteristics
Spinning and spin recovery
The first landing
Assessing flight performance	164	(3)
What changes to make
Side and down thrust
Stability characteristics
Glossary	167	(4)
Bibliography	171	(2)
Index	173