Choosing what to do 4
Be safe! 4
How big? 4
Diagram of a small wind system 4
What can the wind turbine do? 4
Load controllers 5
Choosing battery voltage 5
Battery types 6
Why some popular ideas are not good ideas 6
Car alternators 6
Steel cores in the stator coils 7
Multiple rotors and stators 7
Vertical axis wind turbines (VAWTs) 7
Multi blade rotors 8
Rooftop mounting 8
Saving money off the electricity bill 8
Mounting a wind turbine on a car to charge the battery 8
Using a centrifugal clutch or brake to limit speed 9
Building a duct 9
What goes wrong with homebuilt wind turbines? 9
Useful web pages for more information: 9
Tools 10
Safety etc 10
All-purpose tools 10
For marking and measuring 10
Electrical 10
Resin preparation 10
Steelwork 10
Woodworking tools 10
Using the tools 11
Cordless drill 11
Screwdriver bits 11
Measurements 11
Vernier calipers 11
Levels 11
Compasses 11
Multimeters 12
Soldering technique 12
Electric Arc welding 12
Cutting steel 13
Drilling 13
Tapping a thread 13
Wood saws 13
Other wood cutting tools 14
Sandpaper 14
Power tools 14
Blades 15
Parts of the blade 15
Selecting the wood 15
The blank shapes 16
The trailing edge line 17
Mark out the shape of the blade at each of six stations along its length . 17
Carve away wood above the trailing edge line to create a new face 18
Blade thickness 18
Airfoil shape 19
Hub assembly 20
Cutting the 120 degree angles at the roots 20
The plywood pieces that sandwich the blades. 20
Marking out the holes in the plywood 20
Assembling the blades 21
Balancing 22
Balancing in situ 22
Fine balancing 22
Alternative ways to balance the blades 22
Balancing on a spike 23
Dynamic balance 23
Painting and finishing 23
Mechanics 24
The yaw bearing 24
The alternator 24
Choosing a hub 24
The magnet rotor disks 25
Alternator frame 26
Mounting the alternator to the yaw bearing 27
3600 and 4200 turbines 29
The tail 30
The inclined hinge 30
Tail boom 31
Tail stops 32
Electrics 34
Energy conversion 34
Choosing wire size and number of turns per coil 34
Stator wiring connections 35
Three-phase stators 35
Battery charging with DC 36
The coils 36
12-volt stators marked * 36
Making the coil winder 37
Winding the coils 38
Connecting the coils 38
12-volt stators 39
The moulds 39
The stator mould 39
The 1200 stator mould 41
The magnet rotor mould 41
The magnet positioning jig 42
Resin casting 43
Casting the stator 43
Casting the magnet rotor(s) 45
Alternator assembly and testing 46
Rotor mounting options 46
Rotor mounting studs 47
Assembly 47
12-volt turbine rectifiers 48
Testing the alternator 48
Installation 49
Wiring the batteries 49
The rectifier and brake 49
Meters 50
Controller 50
Inverter 50
Commissioning the turbine 50
Guyed towers 51
Wiring the tower 51
Guyed tower pipe sizes 51
Guy anchors 52
Lifting the tower 53
Taller towers 53
Adjusting the guys 53
Alternator design 54
Matching the blades 54
Tip speed ratio (lambda l) 54
Calculating the blade rotor rpm 54
Blade power 54
Calculating the output voltage vs. speed 54
Wire sizes and power losses 55
Size of wire to use 55
Coil resistance 56
Stator resistance 56
Current and power loss 57
Rectifier loss 57
Efficiency 57
Windspeed 57
Stator cooling 57
Estimating the rpm 57
Blade speed at full power 58
Exploring some design factors 59
Magnet spacing 59
The effects of speed 59
The effects of system voltage on efficiency 59
Varying the voltage with the speed 59
High voltage transmission 59
Glossary 60
LIST OF USEFUL SUPPLIERS 62
MATERIALS REQUIRED FOR BUILDING THE WIND TURBINES 63
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