On a camping trip away from modern infrastructure, you quickly notice how much you have gotten used to the fact that electricity is somehow available anytime and anywhere. The stupid: Most of the time you will realize this when the electricity is not there.
For this case there are now power banks. But what if the power bank is empty? Charging on the go is difficult without electricity.
I faced the same problem on a camping trip a few years ago. At that time I even had a mobile solar cell with me. This provided some energy, but not enough due to the lack of sun. The sun just wasn't shining strong enough. But what I had at the moment was wind.
And so the idea of building a wind turbine that can be produced with the 3D printer was born.
Forgotten at first, this idea got a fresh impetus when I stumbled upon a couple of neodymium magnets at the flea market. For little money I got magnets with which a suitable generator can certainly be built.
Over time, this has resulted in the project presented here. Below you will also find detailed building instructions for the individual components.
Note: The wind turbine is currently (10/11/2020) not yet running perfectly. The blades still have to be adjusted and the generator does not match the characteristics of the wind turbine either. So there is still some work to do here. But maybe. the components shown are a suggestion for everyone who is working on their own design of a 3D printed wind turbine. ?
Overview
- Wind turbine made from 3D printed parts
- HAWT design
- Rotor diameters from 0.5 to 1.2 m possible
- 3D printed wings
- Uses a 3D printed disc generator to generate power
- Safety functions through active pitch adjustment of the wings, mechanical brake and electronic brake function via the disc generator
- Can be printed with any "normal" FDM printer (20 x 20 cm bed size)
Videos
Pictures
Below are a few pictures of different components from different stages of development.
Development
I have documented most of the development and the individual difficulties on Hackaday.io. You can find the link here. 🙂
https://hackaday.io/project/172328-windiy-hawt-wind-turbine
Instructions to build yourself
The structure of WinDIY consists of several individual segments. Since all parts can be printed on a 3D printer with a printing area of 20x20cm, the individual parts must of course still be put together after printing.
Mostly M3 screws and nuts are used in order not to use too many different parts. You can find detailed material lists in the corresponding article.
- Build the wings: WinDIY – build the wings of the wind turbine
- Build the wind vane: WinDIY—assemble the wind vane
- buildhub: Build WinDIY hub including mechanics
- Build the rotating tower: WinDIY – build the rotating tower
- Build main axis: WinDIY—assemble the main axis
- Build pitch actuator: WinDIY – assemble pitch actuator
Electronics
As mentioned above, WinDIY has a few security features. So that these can be controlled in a controlled manner, some electronics are of course necessary. To do this, I started developing a circuit board on which all the necessary components are housed.
The following components have been installed on it so far:
- Three-way bridge rectifier
- Step-down regulator
- Three independent charging circuits for one LiPo cell each
- Three I2C motor drivers to control the motors of the brake actuator and the pitch actuator
- various current and voltage sensors to measure the energy generated and consumed
- Connections for two Hall sensors for measuring the generator speed
- Connections for three sliding resistors to measure the positions of the pitch actuator and the brake cylinder
- Connections for two force sensors to measure the contact pressure of the brake cylinder
- Connections for four NTCs to measure the temperatures of the generator windings and the load resistance.
- Connection to discharge the rectified voltage to a consumer
- Connection and electronics to be able to connect a load resistor PWM-controlled.
- Vibration sensor to detect abnormal vibrations
- two temperature sensors to monitor the temperatures on the PCB
- an electronic compass
- a micro-SD card slot
- a climate sensor for measuring the ambient temperature, humidity and air pressure
Software
The software is developed using the Arduino IDE. You can find the current status in the Nerdiy-Git under the following link:
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I read there are problems with the speed? I'm not 100% sure about the torque being produced but a well running planetary gear in the rotor name should increase the RPM's significantly and wouldn't take up much space?
Awesome project by the way
hey daniel,
thank you for that suggestion. 🙂 I'm currently working on simplifying the entire construction a bit. I didn't even have the planetary gear on my "slip". Thanks for the hint. 🙂
Best regards
Fab
Hello,
The magnets are arranged in Halbach? This increases the magnetic flux.
The 3-way bridge rectifier is a standard model with doids? Maybe try a MOSFET.
Diodes always consume some voltage - with bridge rectifiers this is twice the forward voltage. So with silicon diodes you lose 1.4 volts.
With MosFET you lose almost nothing - microvolts.
Google "mosfet as diode".
You are welcome to use this method in the voltage converter as well.
If there is enough torque but too little speed, maybe use a planetary gear. That's how the "big ones" do it too.
And wind the coils with more turns. This increases their tension and you get something out of it even at lower speeds.
Hey Michael,
it is not a Halbach arrangement. The built generator is also quite simple and not optimal due to the not really fitting magnets. You can get a small impression here: https://nerdiy.de/nerdiskerator-a-generator-from-the-3d-printer/
I also find the MOSFET rectifier solution very interesting. However, I had/have some respect for the correct control of the MOSFETs and therefore entered it a little further down on "the list". On the other hand, the saved losses are quite exciting.
Thank you for your hints. 🙂
Best regards
Fabian
I feel the same way with MosFETs. When I was training to become a power system electronics engineer, the first MosFETs that could handle 2 amperes were just coming onto the market. They were the size of 2 euro coins.
I just googled it out of curiosity and boredom.
I learned that a 3-phase rectifier with MOSfets is not as easy as one with diodes.
For example, 6 diodes are enough, but you need 12 MosFETs. Because you need a full bridge per phase, since the control must be taken from the opposite pole. That doesn't work with three-phase current...
Then I found another circuit with a control IC... LT4320 - also interesting.
I've included a link showing a complete circuit that should work even for 3-phase AC - or 4, 5, 6, lots...
There each MosFET has its own small control and can function as precisely as a diode.
However, he writes that he was not able to start the circuit without an external power supply for the control circuit. But that is probably true for a software simulation.
You should try it.
https://www.mikrocontroller.net/topic/375657
About the planetary gears... This is supposed to ensure that the generator rotates faster in order to induce higher voltages in the coils.
So I had the idea of attaching a ring to the outside of the propellers instead and attaching the magnets there. Outside then the coils.
A few words about the number of magnets and coils...
Any even number of magnets. The number of coils should be lower or higher by 1!
This reduces the starting torque enormously, since the latching forces of the magnets and coil cores almost completely cancel each other out. But then you also need a lot of diodes/MosFETs – two per coil.
Last but not least, you can design it as a wind turbine. Ie there are no propeller flights in the middle, but only at the outer edge. A cone in the middle of the turbine directs the air flow from the center of the turbine onto the wings, and the air should be rotated just in front of the wings to drive the propeller even more.
Then put it all in a tube. This prevents turbulence at the wing tips and that the air displaced from the center simply escapes outwards without driving the wings.
Now the part looks like an airplane turbine, only shorter.
Ok – now it gets even more intense…
The whole thing is now mounted on a mast. A gear wheel is mounted on the mast below the turbine.
Two smaller propellers are attached to the bottom of the turbine. These must be at an angle of 90° to each other. They drive a differential via cardan joints or bevel gears in such a way that the differential is balanced when the propeller is subjected to the same flow – ie it does not rotate.
If one of the propellers has a stronger flow because the wind direction has changed, this propeller turns faster than the other and the differential turns. It engages with the gear wheel attached to the mast and turns the turbine back into the wind.
The advantage over a fin is that the turbine turns slowly into the wind and does not start to flap if the wind changes direction unsteadily.
Are the metal screws in the coils as iron cores?
Well, not bad for a first try.
But it is better to use transformer sheet metal. So off to the transformer sheet metal shop 🙂
Transformer sheets are thin iron discs that are isolated from one another and stacked to form an iron core.
During my training as a power plant electronics technician, we were all allowed to build a transformer.
Stack the transformer core included, put on the previously wound plastic winding body, solder on the terminal strip.
The (manual) winding machine always kept the wire under tension. Tight and tight is better - The magnetic flux decreases with the square of the distance from the core and with it the transmitted power.
A ferrite core should give even better results.
The reason for this are eddy currents in the iron core, which arise when the magnetic field also induces currents in the iron core. Of course, the core immediately shorts them out, causing the iron core to heat up.
This heat is then no longer converted into electrical energy...
The insulated iron discs reduce the current vortices enormously. A ferrite core consists of sintered material in which the current vortices only have a fraction of a millimeter of space and so hardly any energy is wasted.
The only thing missing is a buck-boost converter to be able to generate usable voltage at low speeds and an optimal point control that can adjust the distance between the magnets and the coils so that the best efficiency is always achieved at different wind speeds .
When you've got everything ready, present the thing to Nasa. There is more wind than sun on Mars!