On a camping trip away from modern infrastructure, you quickly realize how accustomed you have become to the fact that electricity is always available everywhere. The stupid thing is that you usually notice this when the electricity isn't there.
There are now power banks for this situation. But what if the power bank is empty? Charging on the go is difficult without electricity.
I faced the same problem a few years ago during a camping trip. Back then, I even had a mobile solar cell with me. It did provide some energy, but not enough due to the lack of sun. The sun just wasn't strong enough. What I did have was wind.
And so the idea was born to build a wind turbine that can be produced using a 3D printer.
Initially forgotten, this idea was given a boost when I stumbled across a few neodymium magnets at a flea market. I got some magnets there for a small amount of money, which I was sure could be used to build a suitable generator.
Over time, this has resulted in the project presented here. Below you will also find detailed assembly instructions for the individual components.
Important: The wind turbine is currently (11.10.2020) not yet running perfectly. The blades still need to be adjusted and also the generator does not quite fit the characteristics of the wind turbine. So there is still some work ahead of me. But maybe the shown components are a suggestion for everyone who is working on his 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 disk generator to generate energy
- Safety functions through active pitch adjustment of the blades, mechanical brake and electronic brake function via the disk generator
- Can be printed with any "normal" FDM printer (20 x 20 cm bed size)
Videos
Images
Below are a few pictures of various components from different stages of development.
Development
I have documented the development and the individual difficulties for the most part on Hackaday.io. You can find the link here 🙂
https://hackaday.io/project/172328-windiy-hawt-wind-turbine
Instructions for building yourself
The structure of WinDIY consists of several individual segments. As all parts can be printed on a 3D printer with a print area of 20x20cm, the individual parts must of course be assembled after printing.
For the most part, M3 screws and nuts are used to avoid using too many different parts. Detailed material lists can be found in the corresponding article.
- Build up wings: WinDIY - Build the blades of the wind turbine
- Set up the wind vane: WinDIY - Assembling a wind vane
- Assemble the hub: WinDIY - Assemble hub incl. mechanics
- Set up the rotating tower: WinDIY - Build a rotating tower
- Build up the main axis: WinDIY - Assembling the main axis
- Set up pitch actuator: WinDIY - Assemble pitch actuator
Electronics
As mentioned above, WinDIY has a few safety features. In order for these to be controlled, some electronics are of course necessary. To this end, I have 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 controller
- 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 generated and consumed energy
- Connections for two Hall sensors for measuring the generator speed
- Connections for three slide resistors to be able to measure the positions of the pitch actuator and the brake cylinders
- Connections for two force sensors to be able to measure the contact pressure of the brake cylinders
- Connections for four NTCs to be able to measure the temperatures of the generator windings as well as the load resistance.
- Connection to be able to discharge the rectified voltage to a load
- 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
- one 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 state 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,
thanks for the suggestion 🙂 I'm currently working on simplifying the entire design a little. I hadn't even thought about the planetary gearbox. Thanks for the tip 🙂
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.
Search for "mosfet as diode" on Google.
You are welcome to use this method in the voltage converter as well.
If there is sufficient torque but not enough speed, perhaps use a planetary gearbox. This is also how the "big ones" do it.
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 have therefore put it a little further down "the list" for the time being. On the other hand, the losses saved 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 disks reduce the current vortices enormously. A ferrite core consists of sintered material in which the current vortices have only millimeter fractions of space and thus hardly "burn" any energy.
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!
Thank you for this page, I'm in the process of testing small 3D imprinted solenoids and I've found some interesting information