This article is devoted to the creation of an axial wind generator using neodymium magnets with stators without metal. Wind turbines similar design have become especially popular due to the increasing availability of neodymium magnets.
Materials and tools used to build a windmill of this model:
1) a hub from a car with brake discs.
2) drill with a metal brush.
3) 20 neodymium magnets measuring 25 by 8 mm.
4) epoxy resin
5) mastic
6) PVC pipe 160 mm diameter
7) hand winch
8) metal pipe 6 meters long
Let's look at the main stages of building a wind turbine.
The generator was based on a car hub with a brake disc. Since the main part is factory-made, this will serve as a guarantor of quality and reliability. The hub was completely disassembled, the bearings in it were checked for integrity and lubricated. Since the hub was removed from an old car, the rust had to be cleaned off using a brush, which the author attached to a drill.
Below is a photo of the hub.
Then the author proceeded to install magnets on the rotor disks. 20 magnets were used. Moreover, it is important to note that for a single-phase generator the number of magnets involved is equal to the number of poles; for a two-phase generator the ratio will be three to two or four poles to three coils. Magnets should be mounted on disks with alternating poles. To maintain accuracy, you need to make a placement template on paper, or draw sector lines directly on the disk itself.
You should also mark the magnets along the poles with a marker. You can determine the poles by bringing the magnets one by one to one side of the testing magnet, if attracted - plus, repelled - minus, the main thing is that the poles alternate when installed on the disk. This is necessary because the magnets on the disks must attract each other, and this will only happen if the magnets facing each other are of different polarities.
The magnets were glued to the disks using epoxy resin. To prevent the resin from spreading beyond the boundaries of the disk, the author made borders along the edges using mastic; the same can be done using tape, simply wrapping the wheel in a circle.
Let's consider the main differences in the design of single-phase and three-phase generators.
A single-phase generator will vibrate under load, which will affect the power of the generator itself. The three-phase design has no similar lack Due to this, the power is constant at any time. This happens because the phases compensate for the loss of current in each other. According to the author's conservative calculations, the three-phase design is superior to the single-phase design by as much as 50 percent. In addition, due to the absence of vibrations, the mast will not swing additionally, and therefore there will be no additional noise when the rotor operates.
When calculating the charging of the 12th battery, which will begin at 100-150 rpm, the author made 1000-1200 turns in the coils. When winding the coils, the author used as much as possible permissible thickness wire to avoid resistance.
To wind wire onto spools, the author built homemade machine, photographs of which are presented below.
It is better to use ellipsoidal coils, which will allow a higher density of magnetic fields to cross them. The inner hole of the coil should be made the same as the diameter of the magnet or larger than it. If you make them smaller, then the frontal parts practically do not participate in the generation of electricity, but serve as conductors.
The thickness of the stator itself must be equal to the thickness of the magnets that are involved in the installation.
The mold for the stator can be made from plywood, although the author solved this issue differently. A template was drawn on paper, and then the sides were made using mastic. Fiberglass was also used for strength. To prevent the epoxy resin from sticking to the mold, it must be lubricated with wax or Vaseline, or you can use tape or film, which can later be torn off from the finished mold.
Before pouring, the coils must be precisely secured, and their ends must be brought out of the mold in order to then connect the wires with a star or triangle.
After the main part of the generator was assembled, the author measured and tested its operation. When manually rotated, the generator produces a voltage of 40 volts and a current of 10 amperes.
Then the author made a mast for the generator 6 meters high. In the future, it is planned to increase the height of the mast by using at least twice as thick a pipe. To keep the mast stationary, the base was filled with concrete. To lower and raise the mast it was done metal mount. This is necessary to have access to the screw on the ground, since repair work It's not particularly comfortable at altitude.
This section contains homemade wind generators made on the basis of disk and axial generators. main feature and the advantage of such generators is the complete absence of magnetic sticking. The stator does not contain iron, the coils are simply filled with epoxy or polyester resin. But unlike classic generators with iron stators, such a generator requires at least twice as many magnets to get the same power. But wind turbines with such generators start at low wind speeds.
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Generator 24 volt 500 watt
This article contains a photo and description of the manufacture of an axial generator for operation on a 24-volt battery. There is data on speed and power, and a propeller with a diameter of 2.1 m is designed for it from PVC pipes 315mm 
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Photo report of a wind generator with a disk generator
Making my fifth wind generator, I made a disk generator for it. I used magnets measuring 50*30*10 mm, placing 8 pieces per disk. The stator has 12 coils wound with 1.06 mm wire 
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Manufacturing of a 1.5 kW wind generator
Description of the manufacture of a wind generator with a power of 1500 watts 48 volts. The author of this wind generator is Gennady Zaborovsky, Samara. The design of this generator differs from the classic one; the generator itself is closed original case, the disks are larger than the stator, and the stator itself is fixed inside, not outside; in general, the details are in the article. 
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Wind generator 2kW for home
A short story about how and why the wind generator was built, what beginners need to take into account and how it all turned out. The article does not contain calculations and detailed photographs of manufacturing, the article is not about that, but there is a story from the author of the wind generator about how to make a wind generator and whether it is needed, how difficult it is. There is also a photo of his wind generator 
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Axial windmill made from scrap materials
Another wind generator, assembled from scrap materials, is raised into the wind. I have already made attempts to make such wind generators before. But this time I wanted to make a better and more durable wind generator so that it would serve for a long time and constantly provide about 30-50 watt/hour of electricity to charge the battery. 
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It turned out to be a beautiful windmill
Some more production photos disk wind generator with your own hands. Although the wind generator itself did not work out due to trivial mistakes, the approach to work and thoroughness are pleasing, and the appearance of the wind generator is good. Wooden blades, folding tail, strong guyed mast, all painted. 
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How to make an axial wind generator
In an article on specific example describes the process of creating an axial wind generator on a car hub. Several stators were made for the generator, a feature of the latest stator is the use of cores in the stator coils to increase power. 
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Axial generator with ferrite magnets
The generator used ordinary ferrite magnets; due to the low power of the magnets, the generator coils contain 325 turns of 0.5 mm wire. Three-phase generator 20 poles and 15 coils. The power is small, only about 30 watts at high speeds. 
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Wind generator 20-pole with magnets 20*5mm
Photo report from brief description creation process homemade wind generator. It is based on a hub from a Zubrenok trailer; the rotary axle is also made from a car hub. The generator is three-phase, 20 poles and 15 coils wound with 0.7 mm wire, 70 turns each. The propeller is two-blade, made of PVC pipe. 
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Small windmill 30 watt
A small two-bladed wind generator was built as a test scaled-down model to supply up to 1A to the battery. As a result, the generator turned out to be successful, and in the future it is planned to build a large axial wind generator. 
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Mini wind generator 20 watt/h
This small wind generator was made for the sake of experience, so that in the future it would be possible to make a large and powerful wind generator. The generator power is now about 50 watt/hour, but this was after some improvements, in particular the manufacture of a new stator, then there were more experiments and modernization. 
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Cheap mini wind generator for battery charging
The simplest mini wind generators are of the axial type; making many small ones is easier than making one large one. Each such windmill infects its battery directly, and the low current allows you not to monitor the charging process without a controller, since it does not harm the battery. 
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Small multi-pole generator 50 watt
The generator used magnets from the first windmill, just like magnets small sizes, it was decided to increase the power by increasing the number of generator poles. To check their calculations and check information from the Internet, several stators were manufactured with different numbers coils and phases. 
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Axial wind generator on the hub from VAZ2108
Classic design of an axial generator on a car hub. The generator is three-phase, the stator has 12 coils, and the rotor disks have 16 25*8mm magnets. The rated power of this generator is 100 watt/h, in weak winds the battery is 2-4A. when the wind increases, the current reaches 12A, maximum power was recorded around 240 watt/hour. 
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Wind generators with an unusual appearance
Axial wind generators from car hubs we've been doing it for a long time. This time we decided to give individuality and beauty to our windmills so that they not only charge our batteries, but also please the eye with their appearance. There is nothing special in the design of wind generators except appearance no, a classic three-phase axial generator. 
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Powerful wind generator based on a homemade axial generator
The design of this wind generator was specially designed for operation in areas with a predominance of low winds. At the heart of the wind generator we have assembled a powerful low-speed axial-type generator with an iron-free stator. The generator was assembled on the basis of a hub from a trailer; a five-meter propeller was calculated and made of wood. Details with many photos of the creation in this article. 
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Single-phase axial wind generator
Homemade wind generator with a disk generator on neodymium magnets. Classic scheme axial permanent magnet generator.Single-phase circuit, 12 coils and 12 magnets on each disk, as a result the baby develops up to 100 watts, and sometimes more.
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Photo report on the construction of 3 wind generators at once
This time, together with our neighbors, we are building three axial wind generators based on car hubs. The generators are absolutely identical, each with a power of 500 watt/hour. We have been making these generators for a long time, this wind generator layout is accessible to everyone to repeat, since it does not require special conditions and tools for making a windmill. We already built a similar wind turbine in the summer, and now we are strengthening the battery of wind turbines. 
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Professionally made wind turbine 2kW
Homemade home wind turbine with a power of 2 kW from an Italian craftsman. More precisely, a professionally made disk axial wind generator with decent power. The article contains many photos of the windmill manufacturing process with a short description.Wind generator based on a homemade axial disk generator. I built it a couple of years ago.
The design of this generator is the first thing you find on the network of practical models of wind turbines. In a narrow circle we call them bourgeois. It was they who began to use this generator layout, due to the availability of rare earth magnets. Now in our country this model is repeated quite often.
At first glance, this is the most affordable design. This is partly true, but the efficiency of iron-free stators is much lower than those with iron. For such generators, magnets are needed thicker, and the quantity is twice as large. So, more about the essence of the project.
The generator has 16 pairs of poles. The magnets used were neodymium disk. Diameter 27 mm, height 8 mm. Very serious stuff. Serious injury may occur if handled carelessly! 12 coils were used. Three-phase generator. Star connection.
To wind the coils, 0.9 mm wire was used, although the calculation was made for 1.06 mm wire. But he was not there at that time. For this reason, there is empty space between the coils, and the generator has not reached design parameters. I wound the coils on a homemade machine. Nothing special.
The design can be absolutely anything. 
For the stator, a plywood mold was made. 
After treating the mold with Vaseline (necessary so that the cast stator can be easily removed from the mold), I positioned the coils.
Soldered accordingly. 
Divorced epoxy resin with the addition of 30% talc (baby powder). I put fiberglass mesh on the bottom of the mold and on top of the coils, since it is more convenient for me to work with it than with fiberglass. I poured the stator, gradually adding resin so that air bubbles came out.
In order to tighten the cover, I marked it so that the screws would pass through the hole in the coil (so as not to damage it). I covered the coil hole with plasticine (removed it after drying) for better cooling.
The next day, I removed the finished stator from the mold without any problems. It turned out smooth and beautiful.
To make the rotor, I took the rear hub assembly from a VAZ 2108. It's not expensive and quite powerful. At the car service they gave me brake discs, again from eight (nine). Discs diameter 240 mm. thickness 10 mm. Having polished work surface, glued magnets. I glued it with superglue, then filled it with epoxy resin.
I welded the wind head and attached the generator to it. The tail is rigidly fixed, that is, storm protection is not performed.
Blades made of PVC pipe with a diameter of 160 mm. I made both a three-bladed version and a five-bladed one. Both options worked fine.
Some conclusions.
Charging the battery begins almost as soon as it starts to rotate (and it rotates from any blow). 1-2 amps from a light breeze, with small gusts 4-5 amps. With normal winds around 10 A.
Conclusion: the goal has been achieved (charging the battery in light winds).
In strong winds I recorded 20 A, the device does not show more.
This model has now been dismantled. Upon inspection, no damage was found, although everything was not even painted.
I plan to do some experiments with it.
Well, here are the actual bullying that I was talking about.
I want to check one more option. Use annealed iron filings instead of ets in the generator stator.
The sawdust is neither small nor large.
Since everything was done under very limited time conditions, and the temperature was 10, no matter how it contributed to the feat of labor, the results were appropriate. Again, a ready-made stator was used, which was not intended for this. However, everything is in order. The photo shows the whole process. I mixed sawdust not with epoxy, but with silicone sealant.
The result was a plastic mass that was easy to work with.
And a test table for this option. 
I think this option, carried out according to all the rules, will give a completely working option.
Verification: 72146f0e872f9296
By the way, the screw turns out to be quite good. Therefore, the last screw was made from a 1.3 m aluminum pipe (see above)
I marked the pipe, cut out the blanks with a grinder, tightened them at the ends with bolts and processed the package with an electric planer. Then I unrolled the package and processed each blade separately, adjusting the weight on an electronic scale.
Protection against hurricane winds is made according to the classic foreign design, i.e. the axis of rotation is offset from the center. Here is the link to the site http://www.otherpower.com/otherpower_wind.html
Those who want to know more will find all the questions they need here, and completely free of charge! This site helped me a lot, especially with the tail drawings. Here is an example of drawings from this site.
I adjusted my windmill tail using the sawing method.
The entire structure is mounted on two 206 bearings, which are mounted on an axis with an internal hole for the cable and welded to a two-inch pipe.
The bearings fit tightly into the wind turbine housing, which allows the structure to rotate freely without any effort or play. The cable runs inside the mast to the diode bridge. (See drawings above)
the photo shows the original version
To manufacture the wind head, not taking into account two months of searching for solutions, it took a month and a half, now we are in the month of February, it looks like there has been snow and cold all winter, so I haven’t carried out the main tests yet, but even at this distance from the ground, the 21-watt car light bulb burned out. I'm waiting for spring, preparing the pipes for the mast. This winter has flown by quickly and interestingly for me.
The VIDEO can be viewed here, (double click on the video opens a direct link to youtube), Yes, if you like it or don't like it, show your opinion.
A little time has passed since I posted my windmill on the site, but spring hasn’t really come, it’s still impossible to dig the ground to wall up a table under the mast - the ground is frozen and there’s dirt everywhere, so there was time for testing on a temporary 1.5m stand plenty, now more details.
After the first tests, the propeller accidentally caught the pipe, I was trying to fix the tail so that the windmill would not move out of the wind and see what the maximum power would be. As a result, the power managed to register approximately 40 watts, after which the propeller safely shattered into splinters. Unpleasant, but probably good for the brain. After that, I decided to experiment and wound a new stator. For this I made new uniform for filling the coils. I carefully lubricated the mold with automotive lithol so that excess would not stick. The coils have now been slightly reduced in length, thanks to which 60 turns of 0.95 mm winding thickness are now placed in the sector of 8 mm (ultimately the stator turned out to be 9 mm), and the length of the wire remained the same.
I added about 30% talc to the epoxy.
The screw is now made with more durable pipe 160mm and three-blade, blade length 800mm.
New tests immediately showed the result, now GENA produced up to 100 watts, a halogen car light bulb of 100 watts burned at full intensity, and in order not to burn it out in strong gusts of wind, the light bulb was turned off.
measurements on a 55 Ah car battery.
Now the final tests on the mast, I will describe the result later.
Well, it’s already mid-August, and as I promised, I’ll try to finish this page.
First what I missed
The mast is one of the critical structural elements
One of the joints (a pipe of a smaller diameter goes inside a larger one)
and swivel unit
now the rest
3-blade propeller (red sewer pipe with a diameter of 160 mm)
I'll start by changing several propellers and settling on a 6-blade aluminum pipe with a diameter of 1.3m, although more power gave a screw with a 1.7m PVC pipe.
The main problem was to force the battery to charge from the slightest rotation of the screw, and here a blocking generator came to the rescue, which even with an input voltage of 2v gives a charge to the battery - albeit with a small current, but better than a discharge, and in normal winds all the energy goes to the battery through VD2 (see the diagram), and there is a full charge.
The design is assembled directly on the radiator, semi-hinged installation, if the installation is correct, it works without problems. In some cases, to start a blocking generator, it is possible to reduce the resistance R1 to 500 Ohms, the transformer is a ferite ring with a diameter of 45 mm, a cross-section of 8 mm by 8 mm (can be wound on a line trance from an old TV), wound with 1 mm wire, first wound 60 turns, and evenly on top wound 21 turns
The charge controller also used a homemade one, the circuit is simple, it was made as always from what was at hand, the load is two turns of nichrome wire (with a charged battery and a strong wind it heats up to red) All transistors were installed on radiators (with a reserve), although VT1 VT2 practically do not heat up, but VT3 must be installed on the radiator! (when the controller operates for a long time, VT3 heats up decently)
photo of the finished controller
simple circuit
The diagram for connecting a windmill to a load looks like this
Back view
My load, as planned, is the light in the toilet and summer shower + street lighting (4 LED bulbs which turn on automatically through a photo relay and illuminate the yard all night long, at sunrise the photo relay is activated again, which turns off the lighting and the battery is charged. And this is on a dead battery (removed from the car last year)
photographed protective glass(photo sensor at the top)
I bought a photo relay ready for a 220V network and converted it to power from 12V (I bridged the input capacitor and soldered a 1K resistor in series with the zener diode)
Now the most IMPORTANT!!!
From my experience, I advised you to first make a small windmill, gain experience and knowledge and see what you can get from the winds of your area. After all, you can spend a lot of money, make a powerful windmill, but the wind power is not enough to receive the same 50 watts and your windmill will be like submarine in the garage. Here BETTER A TIT IN YOUR HANDS THAN A WOODPECKER IN A JO-E!!!
The simplest anemometer. The square side is 12 cm by 12 cm, a tennis ball is tied to a 25 cm thread.
I made this anemometer
Many readers often ask the question, how much does such a gene produce?
I had to make a short video for clarity.
We never think about how strong even a small breeze can be, but it’s worth looking at how fast a turbine sometimes spins and you immediately understand how powerful it is.
Wind, you are a mighty wind...(photo from the yard)
The process of modernizing the windmill is completed, this is what it looks like at this stage. The video shows its operating mode (I filmed it with a camera, so the discreteness of the propeller is visible, in fact it is spinning as if it had been blown up). Works in very low winds BLOCKING GENERATOR.
The beginning of the rise into the wind
And here it’s already in the wind
All wind generator calculations (thanks to Nikolai) can be seen here
Here are sites where you can find a lot of interesting things:
Don’t be lazy to look at these sites!!!
For Kharkiv residents and not only
Good luck to all!!!
I will be glad if I helped someone at least a little, all questions on the wall or email
For everyone who has finished reading this article, I offer an excursion into another successfully repeatable design
I haven’t returned to this article for a long time, more than two years have passed since this article was written, during which time the design was repeated many times, I can judge this from the reviews that came through e-mail. Many repeated the design one to one with my version, but those who turned to me for help, I advised them to do only the three-phase version, and the result was much better.
With the permission of Alexey Viktorovich Mikhalchuk, I am posting one with worthy repetitions, the design of a three-phase generator.
Before meeting me, Alexey had prepared almost everything to replicate my design; subsequently, practically nothing was changed, with the exception of I convinced him to make the generator three-phase. To Alexey’s surprise, the generator turned out to be quite good, it charged the battery quite quickly, but since the design was temporary (Alexey did not believe in success until recently), this generator was subsequently dismantled, it was decided to add magnetic poles, and make the design more reliable. Subsequently, a 16-pole axial generator was born, I can say that it exceeded all expectations, even mine.
I will not repeat myself in the description. Just a quick summary of some information
12 coils of 1.18 wire took 1.5 kg, 75 turns per coil.
The thickness of the coil is equal to the thickness of the magnet - 8mm
Inner diameter coils equal to magnet diameter -25 mm
Magnets 16 pairs 25*8
Discs steel thickness 10mm diameter 25cm
Blades made of aluminum pipe with a diameter of 300 mm
Metal thickness 4mm blade length -1m
Such a generator produces more than 500 watts without any problems!
We look at the photo for some aspects of generator manufacturing
During the operation of this generator, a significant design flaw was identified; Alexey neglected protection from hurricane winds, so the blades were destroyed. For everyone who repeats the design with WIND YOU CANNOT JOKE, it is necessary to make protection against hurricane winds, it will be cheaper than changing the blades every time.
At the moment, Alexey has corrected the shortcomings, and the windmill brings him significant help
Here Alexey threw in a few more photos after the modernization of the windmill
and a short video
on the left is an asynchronous wind generator, on the right is the generator that is in the description. Well, that’s all for now, saw the weights, Gentlemen, they are golden!
For Kharkiv residents and not only
Sent by:
Homemade windmill with generator. Of interest is mainly the type of generator. This design is very common and simple, however, it has not yet been presented on our website.
Author Burlaka Viktor Afanasyevich.
I did a photo shoot of my little windmill or, as I call it, current model. Since I built it unexpectedly for myself, I just decided to practice and find out what would happen. At first I didn’t photograph anything, I didn’t think that they might be interested in it, the photo shoot turned out in the reverse order, i.e. deduction - from the whole to the parts.
And now a little history, and everything in order:
Building a wind turbine has been my long-time dream, but there were many obstacles. He lived in a city apartment, but there was no dacha. Then moving from one city to another, then to a third. I have been living in Svetlovodsk for the last 18 years. All the conditions are here - private cottage for two families, 5 acres of vegetable garden and the same amount of garden. To the east and south there is open terrain, to the north and west the terrain is higher than mine. The winds are not kind, i.e. not very strong. Well, I think I'll build a windmill here for the soul.
But when I got serious, it turned out to be not so simple. I did not find any suitable literature. For a long time I couldn’t decide on a generator; I didn’t know how to make the blades correctly, what gearbox to use, how to protect it from a hurricane, etc. As they say, it was cooked in own juice. But I knew that if I really wanted it, everything would work out.
I slowly made the mast. Using ferrous metal, I selected suitable pieces of pipe, starting with a diameter of 325 mm and 1.5 m long (to fit in the trunk of my car). In exchange, he sold scrap metal. The result was a mast 12 m long. I brought a defective one for the foundation foundation block from the high voltage support. I buried it 2 meters into the ground and 1 meter remained above the ground. Then I scalded it with two belts from the corner and welded brackets to them. At the ends of the brackets to anchor bolts welded “plates” of 16mm iron measuring 50 x 50 cm, connected to each other by powerful loops. I bought soft 10 mm cables and turnbuckles on the market, everything is anodized and does not rust. I welded and buried an anchor under the removable winch. The winch also had to be made homemade, using a ready-made worm gear. In addition, I installed a U-shaped support about 2 m high, on which the mast should rest. Since there was nowhere to rush, the mast was made without haste and therefore, in my opinion, it turned out beautiful and reliable.
And then God, seeing my work, blessed me to go to the forum http://forum.ixbt.com/topic.cgi?id=48:4219-74#1829. I re-read it all, registered, and began to gain experience. I started remaking a self-generator, and when I translated from English “overseas” sites (Hugh Pigot and others) on building end-mounted generators without iron in the coils, I really wanted to try and do it myself, at least in miniature.
General view of the windmill
Generator
Generator, side view.
Wire output.
Blades, housing and disassembled generator.
I decided to build a working smaller model that would deliver up to 1 amp per 12-volt battery.
To make the rotor, I bought 24 pieces in Znamenka at the Acoustics company. neodymium disk magnets 20*5 mm. I found a hub from a walk-behind tractor wheel, the turner, according to my drawings, turned two steel disks with a diameter of 105 mm and a thickness of 5 mm, a spacer sleeve with a thickness of 15 mm, and a shaft. I glued magnets, 12 each for each, and filled them halfway with epoxy, alternating their polarity.
To make the stator, I wound 12 coils of enamel wire with a diameter of 0.5 mm, 60 turns per coil (I took the wire from the demagnetization loop of an old unusable color picture tube, there is enough of it). I soldered the coils in series, end to end, beginning to beginning, etc. ( Here I “don’t understand”, if it’s possible to connect everything in series to get one phase? It is advisable to check during manufacture. Editor's note) It turned out to be one phase (I was afraid that there would be too little voltage). I cut out a shape from 4 mm plywood and rubbed it with wax.
It's a pity that the complete form has not been preserved. I put wax paper on the bottom base (I stole it from my wife in the kitchen, she bakes on it), and placed a mold on it with a round piece in the center. Then I cut out two circles from fiberglass. One laid on wax paper the bottom base of the mold. I laid out the coils soldered together on it. The leads from the stranded insulated wire were laid into shallow grooves cut with a hacksaw. I filled it all with epoxy. I waited about an hour for the air bubbles to all come out and the epoxy to spread evenly throughout the entire mold and saturate the coils, top up where needed, and cover with a second circle of fiberglass. Place the second sheet on top wax paper and pressed it with the upper base (a piece of chipboard). The main thing is that both bases are strictly flat. In the morning I disconnected the mold and removed a beautiful transparent stator 4mm thick.
It’s a pity that epoxy is not suitable for a more powerful windmill, because... fears high temperature.
I inserted 2 bearings into the hub, a shaft with a key in them, the first rotor disk with magnets glued and half filled with epoxy, then a spacer sleeve 15 mm thick. The thickness of the stator with filled coils is 4mm, the thickness of the magnets is 5mm, a total of 5+4+5=14mm. On the rotor disks, 0.5 mm edges are left on the edges so that the magnets rest against centrifugal force (just in case). Therefore, we will subtract 1mm. 13mm left. There is 1mm left for the gaps. Therefore the spacer is 15mm. Then the stator (a transparent disk with coils), which is attached to the hub with three 5 mm copper bolts, they can be seen in the photo. Then a second rotor disk is installed, which rests on the spacer sleeve. You need to be careful not to get your finger caught under the magnets - they get pinched very painfully. (Opposite magnets on the disks must have different polarities, i.e. attract.)
Sketch of a wind turbine.
The gaps between the magnets and the stator are adjusted by copper nuts placed on copper bolts on both sides of the hub.
A propeller is placed on the remaining protruding part of the shaft with a key, which is pressed against the rotor through a washer (and, if necessary, a bushing) and a propeller. It is advisable to cover the nut with a fairing (I never made one).
But I made a canopy roof over the rotor and stator by sawing an aluminum pan so as to cover part of the bottom and part of the side wall.
The propeller was made from a meter-long piece of duralumin irrigation pipe with a diameter of 220 mm and a wall thickness of 2.5 mm.
I simply drew a two-bladed propeller on it and cut it out with a jigsaw. (From the same piece I also cut out three blades 1 m long for a windmill on a self-generator, and as you can see, there are still some left). I rounded the leading edge of the blades “by eye” with a radius equal to half the thickness of the duralumin, and sharpened the rear edge with a chamfer of approximately 1 cm at the ends and up to 3 cm towards the center.
In the center of the propeller, I first drilled a hole with a 1mm drill for balancing. You can balance it directly on the drill, placing the drill on the table, or hang it on a thread from the ceiling. You need to balance very carefully. I balanced the rotor discs and the propeller separately. After all, the speed reaches 1500 rpm.
Since there is no magnetic sticking, the propeller rotates happily from the slightest breeze, which you can’t even feel on the ground. During operating wind it develops high speeds, I have a 2A direct-connection ammeter, so it often goes off scale with a 12 volt old car battery. True, at the same time the tail begins to fold and rise upward, i.e. automatic protection against strong wind and excessive speed is activated.
The protection is made on the basis of the inclined axis of rotation of the tail.
The axis deviation is 18-20 degrees from the vertical. I apologize for the drawing, I tried to copy it from an overseas site http://www.otherpower.com/otherpower_wind.html
This windmill worked for me for 3 months. I took it off and disassembled it - the bearings are fine, the stator is also intact. The magnets are a little rusty in places where the paint did not get on. The cable goes directly without a current collector. I have it made, but I changed my mind about installing it. When I dismantled the small windmill, it was not twisted. So I was convinced that it is not needed, only extra hassle. It produced up to 30 watts of power. Propeller noise when closed windows inaudible. And when open it’s not very audible, if healthy sleep, it won’t wake you up, especially against the background of the noise of the wind itself.
There is a desire to make a large one using the same scheme, although the stator needs to be made differently, not using epoxy. I'm thinking about this now. In the meantime, during these three months, I built a windmill using a three-bladed self-generator with a diameter of 2.2 m and a power of about 400 watts. About him in the next article.