Special: How to make an aerogenerator (windmill or wind turbine)

Homemade wind turbine

Following the line of inventions of renewable energies, today I bring you another special, this time for making a wind turbine. Like the previous special for making a solar panel, this one is also by the same author, and we have been in charge of translating it. By the way, if you don't feel qualified or if you have entered here looking for a wind turbine for domestic use, I recommend you to go to Amazon and have a look, as there are very good prices.

The main features of this wind turbine The voltage of the motor or generator can vary depending on the type of motor or generator we install, but it will normally be around 12v of efficient voltage. Enjoy making this invention as much as I enjoyed translating it for you:

After a lot of searching all over the internet, I realised that all the designs had five things in common:

  • A generator. (Link to Amazon)
  • Shovels.
  • Wind direction system (Rudder).
  • A tower to raise the turbine whichever way the wind blows.
  • Batteries and an electrical control system.

By organising the subject a little, I managed to reduce the project to just five systems, which, attacking them little by little and one by one, is not entirely complicated. I decided to start with the generator. Looking at other people's projects on the Internet, I realised that there were people who decided to make their own generator, others who used the resident energy of permanent magnet motors, and others who simply looked for a generator for their own power supply. generator. So I decided to start looking.

The generator

Many people used the tape drive motors from old computer tape drives. The best ones for this are the Ametek 99 volt on a continuum that works very well as generators. Unfortunately, they are very difficult to find, although you can always try other similar models from Ametek (You can check Amazon to see if this equivalent will work for you).

There are many other makes and models of permanent magnet motors other than the AmetekThe permanent magnet motors are not designed to be generators, but they may not work as well, as permanent magnet motors were not designed to be generators. Normal motors, when used as generatorsIn order to achieve an output similar to that of normal operation, they have to be driven much faster than their nominal operating speed. With these data, we can draw a conclusion, what we are looking for, is a motor that gives a lot of voltage at low revolutions. Stay away from motors with high revolutions and low voltage, because it will not do any good. What we are looking for, more or less, is a motor that gives us about 12v of useful voltage with very low revolutions (325 rpm approx.). When you have it, to do the test, connect it to a 12v bulb and give the motor a strong turn with your hand, if it really works, the bulb should light up as it normally does.

Engine for homemade wind turbine

I have obtained some engines Ametek which run at 30v on Amazon (or the alternative on Amazon) for only 26$. These days they are getting cheaper as many people are buying them to make their own windmills.

The shovels

I did some more research for the paddles. I saw that a lot of people carve their own paddles out of wood, but that's too complicated, considering that other people made their paddles out of PVC pipes with the same result. Here I leave you a website where you can find out how to make your own aerodynamic PVC paddles.

Wind turbine blade

I more or less followed the guide by changing a few things. I used black ABS tubing that came pre-cut. I used the 6 inch diameter pipe instead of 4 and 24 inches long instead of 19 5/8. The difference is that it will weigh a bit more, but the revolutions will be higher as it will pick up more wind, and we will gain a bit of power.

The three wind turbine blades

I started by marking and cutting the tube lengthwise into four equal pieces, cut one and used it as a guide for the rest, filing the edges and weighing them if necessary to avoid unbalancing the device. Finally, I ended up with 4 blades, three for use and one spare. To improve the aerodynamics you can file the edges as blades to "cut" the wind and get less drag.

Attachment of the blades

The next step was to attach the blades to the motor, for which I used bolts. A gear wheel appeared in my workshop that fitted perfectly on the motor shaft, but it had neither the necessary holes nor the diameter to make the perfect union with the blades, so I added an aluminium disc of 5 inches in diameter and ¼ inch thick that was perfectly suitable for the union of the blades. The easy solution to this was to join the two pieces together and leave them completely fixed.

Attachment of blades with holes
This is the drilling and engraving of the parts.
Clamped blades
The assembled parts, including the blades.
Rear-mounted blades
The other part of the complete assembly.

Clamped blades plus aerodynamic look

Mounted aerodynamic tip

On one of my trips to the hardware store, I found this cover which is perfect for the tip of the blades, thus avoiding wind resistance and distributing even more air to the blades.

Detail of mounted blades

Update: Later, on a very windy day, I broke the blades of my wind turbineI decided to make this change, I lost in length, but gained in resistance. In order not to do without any of them, you should do it like this from the start.

The structure

Support and weather vane

The next step was the assembly of the skeleton of the turbineTo keep it simple, I chose to place the motor on a 2×4 inch piece of wood held in place with adjustable clamps. Also, to protect the motor a bit, I put it inside a PVC pipe that had the right diameter. I placed a weather vane to direct the skeleton towards the wind, mine was made of rigid aluminium and had the dimensions shown in the picture, although that is not something to worry about.

Support and weather vane 2
This is another view of the wind turbine skeleton.

Rotating mast

The next step was to come up with some kind of mechanism that would allow for free rotation of the turbine depending on which way the wind was coming from. After a lot of thought, I realised that with a 1 inch diameter metal bar, 10 inches long, inserted into a 1 inch 1/4 inch diameter steel tube, it would work perfectly. I would use the 1 inch steel tubes on both sides, and for the body or tower, I would use the 1 inch and 1/4 inch. To choose the position of the steel tube, I looked at the skeleton and calculated the centre of gravity, as simple as looking at the place on the wood (the 33 inch) where it stays in balance. The generator cables will pass through a hole in the centre of the support tube.

Ground anchoring

For the base of the tower, I cut a 2-foot diameter base out of plywood. I made a U-shaped assembly out of 1 inch tubing which is where the other end of the 1 and ¼ inch diameter pipe or tower would go. Like the top, it is free to rotate wherever it wants too, so it gives it more mobility in case the top gets stuck at any given moment. Also the U is movable in the form of a hinge to facilitate the raising and lowering of the wind turbine. Between the U and the 1 inch tube, I added a T with a hole in it so that I could pull the cable through. This is shown in a photo below. I will also include some holes in the plywood to put some anchors for the floor.

Ground mounting and top mast

This picture shows the head and base together. Now you can get an idea of what it will look like, imagine a 10 foot pipe between the ends.

Top support and weather vane

Then I painted all the wooden parts with a white protective paint. In this photo you can also see an addition to the glue, it is a piece of lead to counterbalance.

Complete top bracket assembled
Here is the whole head assembly.

The charge controller

Update: We have released a new and improved version of the charge controller, it works better and the price is much lower.

After getting all the mechanics ready, I decided to start with the electronics. The system would be composed of a system of one or more batteries to store the accumulated energy. by the wind turbineThe battery packs are equipped with a blocking diode to avoid wasting energy from the batteries, a secondary load to dump excess energy when the batteries are fully charged, and a charge controller to manage it all.

I decided to Google around for some information on wind turbine charge controllers. I was pleased to find some fairly simple schematics, like this one, which was the one I used.

As this website explains the creation of such a circuit very well, I will only touch on general aspects of it.

The basic principle of the controller is to control if the battery is charged to send current from the turbine to them or divert it to a load to avoid damaging the batteries. In the link it is all very well explained.

Wind turbine controller

This is a picture of the built controller, it's all on a plywood board so I can test and fix bugs. Later I will assemble it all in a box.

The printed circuit board where the complex electronics are located is clearly visible. A silver bracket with two switches that allow you to switch between batteries and charging.

The black heatsink at the bottom left has two 40A blocking diodes. I use only one at the moment, but I could use the other one. for another wind turbine or to add a solar panelwho knows. The double row of gold coloured rectangles at the top is the load, made up of high power resistors, at 2ohm intervals. It serves to dump power when the batteries are charged or to test the turbine. Excess power from the turbine can be used for a heater or to include a second battery. Below to the left of the resistors, there is a fuse, the main fuse, together with a square grey 40A relay, taken from a car. It is in charge of sending power either to the batteries or to the load. All along the right side, you can see, in black, all the connections on a terminal block.

In operation, the wind turbine is connected to the charge controller. It then passes from the controller to the battery. All loads are taken from the batteries. If the battery voltage drops below 11.9v, the controller switches the turbine to the batteries. If the battery voltage rises to 14v, the controller switches the turbine to the load. If you look, you will see potentiometers to adjust the voltages for both states. I chose 11.9v for when it is discharged and 14v for when it is charged because of advice found on different websites about optimal charging of lead-acid batteries. When the battery voltage is between 11.9v and 14v, the system can be manually switched to either state. Normally, the system is automatic. When charging is in use, the green LED lights up, when charging the battery, the yellow LED lights up.. This allows me to have a minimum of system information, I also use the multimeter to measure both the battery voltage and the turbine output voltage. Later on I will add some voltage meters and put everything in a more decent box.

I used a variable voltage power supply to test the different battery states (the 11.9v and the 14v) so I could adjust the potentiometers to my liking.

Update: In the end I changed the shunt voltage at the load from 14 to 14.8 v, it seems to work better for charging this type of battery.

Update: I discovered that there is an order to connect things to the controller and not damage anything. I once connected the turbine and solar panel before the batteries, and because of the voltage swings, the relay and voltages started to do strange things because the battery was not there to stabilise, it can also damage the circuit. What should always be done is connect the batteries first and then the wind turbine or the solar panel. To disconnect is the same, first disconnect the systems (panel and turbine) and then the batteries.


Click on the image for a larger view.
Click on the image for a larger view.

Update: Finally, here is a schematic of my charge controller. There are some small variations from the diagram on the website above. I substituted some parts I had on hand so I didn't have to buy them. You can do the same, with enough knowledge, I for example, the MOSFET amplifiers, I have not placed them the same, as well as the resistors.

The final assembly

So far we have all the parts of the project complete, it only remains to put them together.

Anchored mast

When I arrived at my farm, the first thing I did was to start with the reinforcement of the tower, I placed the turbine head on the 10 feet long and 1 ¼ inch diameter pipe and the base at the end of it. From here it was all very quick. I used nylon ropes to secure the 10-foot pole to the ground with wooden stakes and turnbuckles at the ends. Thanks to the hinge at the base, I was able to lower and raise the tower easily. When it's all up and running, the nylon ropes and wooden stakes are replaced by steel cables and metal stakes.

Mast mountings

This photo shows a close-up of how I tied the ropes to the metal pipe. Simple and effective at the same time.

Bottom cable outlet

This other photo shows the base of the tower, resting on the ground, and with the turbine cable exiting through the T-shaped section. The cable used is a normal electrical installation cable, simply cut and connect the turbine to the controller.

Assembled wind turbine

I greased the whole tube at the bottom of the head and it slid all the way to the end stop by itself.

All that remains is to wait for the wind to blow and start producing.

Wind turbine assembled and running
The turbine is working like a charm, even in light wind.

Complete circuit

Here is the whole setup of controller, battery and wiring electronics. You can also see a 120v inverter connected to the battery and a multimeter to track the battery voltage and turbine output. My electric shaver and battery charger are connected to the inverter running at 120v. Later I also ran a cable to my camp.

Complete circuit and load
In this photo, all the electronics.

The multimeter shows an output of 13.32v, the load is provided by the shaver and the batteries via the inverter.

Controller test

Here the multimeter shows an output of 13.49v. The turbine voltage rises a little as the wind force rises, this is due to having a load. When it is spinning very fast and the battery voltage is exceeded, the diode takes over the blocking. When the limit is exceeded, the load (resistors) suddenly enters the turbine. One of the precautions to be taken is to watch out for changes in wind direction when working with the wires, as you could snap them.

Complete circuit plus inverter

I realised that the whole controller setup was too dangerous. I tidied up the wires a bit and put all the electronics on a piece of wood on top of a plastic box. Then I ran a long cable from the inverter to my camp, so it was safer.

Complete assembly
Another view of the configuration.
Final wind turbine test
Here is my laptop running thanks to the turbine.

How much did it all cost, here is a table.

What is it? From where? How much?
Engine / generator. Amazon $26,00 = 18,27€
Various piping. Hardware. $41,49 = 29,16€
Piping for the blades. Hardware. $12,84 = 9,02€
Several teams. Hardware. $8,00 = 5,6€
Ducts. Hardware. $19,95 = 14,02€
Wood and aluminium. Scrap heap $0,00
Power cable I already had it. $0,00
Rope and tensioners. Hardware. $18,47 = 12,98€
Charge regulator ComoHacer.eu Shop 16,95€
Battery. Amazon $0,00
Investor Amazon $0,00
Painting I already had it. $0,00
Total 104€

Not bad. Considering that professional turbines comparable to this one are worth between 750 and 1000$.

Wind turbine upgrades

Modifications and improvements I would like to make to it in the future:

  • Mount the electronic components in a watertight enclosure.
  • Add meters for battery voltage and turbine voltage.
  • Add a tachometer to know how fast it is turning.
  • Add more batteries.
  • Add another wind turbine or solar panel to produce more energy.
  • Obtain a higher voltage inverter.
  • Emergency braking system for high winds.
  • Concrete base for the tower.
  • A higher tower with steel cables and stakes.

Encapsulated controller

I finished the rebuild of the controller. It is now in a semi-storage enclosure and I have added a voltage meter. It has inputs for several sources and different outputs for external loads.

Controller connections

These are the controller inputs, two inputs for solar panels and one for the windmill. This configuration can vary according to taste.

Controller connections 2

This picture shows the controller outputs. There are connections for batteries, for charging and for 3 12v outputs.

Controller inside

This is the inside of the controller, basically I transferred everything from the wooden board to here. I added a voltage meter and a fuse for each output.

Click to see a larger image.
Click to see a larger image.

This is the schematic of the new controller, it is almost the same as the old one except for the two changes I mentioned above.

Click on the image for a larger view.
Click on the image for a larger view.

This block diagram gives an overview of the assembly.

Too difficult, you can always check Amazon to see if you can see any wind turbine for domestic use for a good price.

A great tutorial that you can't miss, if you liked it, share it, so we can continue with so many projects that we have in mind. Enjoy it!!!

Useful links:

  • Frequently asked questions about the windmill (FAQ's); Link.
  • You may also be interested in; How to make a solar panel.
  • Complete PDF tutorial created by Como Hacer; Link.
  • Tutorial of the original wind turbine in English; Link.

440 thoughts on “Especial: Cómo hacer un aerogenerador (molino de viento o turbina eolica)”

  1. It is very important that the generator can rotate and charge the batteries, but if they reach their maximum voltage (14.2 Volts) it is necessary to act on the current of the inductor field, so that although it rotates, it does not produce too much generation. This is the way the charging system of a car works...
    IN ADDITION it is convenient to make a modification with respect to the wind to reduce the impulse of the blades, in the mills for water extraction, they have a centrifugal system that sees closing the mill with that object and IN ADDITION a brake system to eliminate the possibility of destruction by excess of revolutions .... The brake systems of Automobiles present an innumerable quantity of options... I hope it is useful to you UBALDO from San Miguel, Province of Buenos Aires, ARGENTINA. 27 April 2022 2240hs

  2. David Peña A

    We are going to make it to have alternative energy in a Permaculture project.thank you.

  3. Eduardo Bruna

    Dear Alberto: You have proved to be an excellent communicator and your presentation is unbeatable, I will probably try to make one, from Aristobulo del Valle, Misiones Province, Argentina. Thank you very much and a hug (in spite of the COVID). Eduardo

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