Draft 1 – 14-Jul-12
To build a mid powered wind turbine to learn about producing enough power to get a small cabin off the power grid.Razor VAWT
Picture from Windgenkits (dot) com
I’ve wanted a VAWT but could not see spending the about $1500 for a new one or 1000 to build up a mid powered 500-1000 watt unit from an assembly of kits. This building included building my own generator from exotic high priced magnets and rolling and casting my own stator windings.
Info from the internet and friends relates that rewiring a Fisher and Pakel (F&P) washing machine motor will produce a good generator for use in a wind turbine or water turbine. It also stated that there were good results obtained and there were several wiring options that would produce and output power band to match the speed of the turbine blades I selected. I.E. options to get better results.
With the encouragement of some friends, I decided to plunk down the doe and see what I could make happen.
Rotor outside Rotor magnet sideF&P Rotor Magnets F&P Rotor Magnet 4 Poles
Notice that the 12 magnet strips glued to the rotor have four magnets in them. They are polarizes as North, South, North, and South. This results in 48 magnetic poles on the rotor, 12 x4=48.
I Goggled some info and watched several YouTube videos. There were a few sites with good info, see the resources section, but most related there experience with DIY building with little hard data as to the results. One site produced compelling generator results by using his lathe as to turn the generator. Nowhere did I find a step-by-step build with info about the power output, physical performance, and demonistratable results, like fit for purpose to power an off grid system.
The first major step was to get a motor, rewire it, and see if it would output useful power. So I was off to get a motor. Due to my lack of experience and knowledge, Fisher and Pakel washing machine motor from a front load LG washer was selected. A top load washer motor from machine with a dasher would likely be better due to its longer axle and top load bearings, since this is the way it will be used in the VAWT.
Rewiring as a generatorStator Coils
Stator as per factor, all coils in series, 3 phase outputStator Rewired
Stator being rewired
The resources I found suggested wiring the stator in a 3 phase star circuit in groups of 6 coils. This was done by wiring the 1st and 4th coil in series ton phase 1, 2nd and 5th in series to phase 2, 3rd and 6th in series as phase 3. Since the stator had 36 coils, this series wiring was repeated 6 times, 6*6=36 coils, and tied in parallel to the 3 wires for the 3 phases that were brought out of the generator.
One side of each of the three sets of two coils was tied together, making the center of the start wiring. That connection was not brought out or even tied to the other group of 6 coils.
Coil winding theory
The theory was that 36 coils produced a max of 500 volts when cranked up to speed with factory wiring. Factory wiring had all coils in series, so each coil could produce a max of about 13.9 volts AC each. By putting 2 in series you could get about 1.7 time the individual voltage max or about 24 Volts AC. With them generator on a wind turbine the speed varies with the wind. The hope is that the output will be above charging voltage, say 13.8 volts enough of the time to fully charge the batteries.Coil Wiring2of6 Coil wire attachment
How the coil wires are attached to the 3 output wires
Stator MountingStator mounting
Stator is mounted to mounting plate and plastic drum with 6 screws.
Note this is before it was rewired. It mounted to the mounting plate into the plastic outer drum. Outer drum is behind plate and cut down to workable circular size. Rotor, rotor center bolt, and motor hookup wiring are removed in this picture
Axle Bearings and MountingOuter Tub surgery
Outer Tub and motor mounting center cut out for easier use with the VAWT.
Top Bearing F&P Short Axle Axle side view
Short motor axle with tub mounting arms press fit on the end of the shaft. Axle show is from a front loading LG washing machine. Thanks to Michael at M&W Appliance in Richardson, Texas for the help in identifying and removing all the parts I needed from the washing machine. He offers fair prices and good customer service for appliance repair or purchase.
Arms – Spokes
I decided to use the mounting arms sold by Windgen and adapt them to the F&P washer motor 3 arm mounts.
Tri-Star Bearing Carrier:
Drilling tub arm mounting holesMounting Holes Mount arms on tub arms
Tower Mounting Plate and FlangeTower mounting plate
Tower mounting plate set on top of “bottom” of the F&P motor. No holes for the tower mounting plate marked or drilled yet. These will be 4 each ½” diameter holes.
I wanted to mount the VAWT on a tower rather than a building so I decided to use the 4 bolt pole mounting plate sold by Windgen. I like these guys designs and they are sheet metal workers so there prices and quality were good.
So that the F&P motor arms and blade assembly would mount centered and balanced on the pole, I needed a mount coming out of the bottom of the F&P motor. That was tough because the rotor was on the bottom of the F&P motor, turning with the wind. Several of the mounts I found required extensive metal work and welding and some looked like a sideways “U” with custom bearing mounts.
My design was to mount a plate on the bottom of the F&P motor supported by stand offs welded to the bolts that held the R&P mounting plate to the original washer tub outer tub. This mount held the tub, outer tub, suspension, clothes, and water as well as all the force vectors from the motor, so I assumed my approach would work well. Time will tell!
My jig for welding the factor bolts to 5” 3/8” diameter all-thread as extensions to mount the F&P to the tower mounting plateBolt welding jig
The bottom of the jig held the factory bolt for welding to the all-threadBolt welding jig bottom
I used the nut a the top to compress the joint between the all-thread and the factor bolt headBolt welding jig top
Welding all-thread to the factory bolt head but, getting them very straight was done with a rubber mallet!Welding bolt rods
Picture from Windgenkits (dot) com
Turbine blade design to produce high rotational speed maximized generator output. For this reason, and due to the center mounted vs. dual bearing mounting blades, I choose the R2-40 Razor Blade wind turbine blade kit from Windgen.
Razor Blade Kit
Kit picture from Windgenkits (dot) comRazor wings
Razor Blades hung for dryingRazor Blade pipe mount
Blade mounting bracketRazor Blade mount Razor Blade mount drawing
Wind Turbine Blades – Lenz II
Here are the best blades for building a first VAWT. They require two bearing mounts which requires a long axle. I assume the axle from the top load with dasher Washing machine with a F&P motor would work well for this, as it has a longer axle and bearings designed for top loading.Lenz II
Picture from Windgenkits (dot) comLenz II VAWT Example 1
Picture from The back shed (dot) comLenz II VAWT Example 2
Picture from The back shed (dot) com
When I hand turn the generator setting on a bench it produces 2 VAC at a very low speed, something like 60 RPM. From this I predict good result from the wind.
I have no generator real world output data yet. I’m waiting for money for a tower pole and concrete for a base. Also, it seems city restrictions are designed to not favor the DIY homeowner, but I bet I can at least erect and test for a good period of time before I am forced to comply to over stringent codes. After that I’ll move it to the land I’m planning to build on and use it to produce off the grid power.
Again time will tell!
VAWT = Vertical Axis Wind Turbine
Stator = the part of a generator that composes the coils and does not rotate
Rotor = the part of a generator that composes the magnets and rotates around the stator.