My 3D printed generator led to my first successful video on YouTube. Shortly after uploading, the video achieved more than 2000 views within a single day. Such high numbers were unimaginable and new to me. The origin of these views remained unclear at first. However, through research on the Internet, it turned out that they came from the platform HACKADAY. That’s how I became aware of this fantastic platform. In the meantime, there are even several articles on HACKADAY that shed more light on my projects and about which you can learn more.
3D printed Generator components
- Rotor: The rotating part. It receives the magnets.
- Stator: The fixed part. It holds the coils.
- Coil: 0.5mm enameled copper wire was used. The electric voltage is induced in the coils.
- Shaft: The main rotating shaft. A windmill or waterwheel can be attached to it.
Winding the coils
The coils from the 3D printed Generator were wound from 0.5 mm thick enameled copper wire. For this purpose, I designed a special device, which is made with the help of 3D printing. Unfortunately, I did not note the exact number of turns, but it is recommended to count them to ensure that each coil has the same number of turns. I applied these windings with a cordless drill, although you can do this manually as well.
Once the coils were wound, they were inserted into the stator, which was also 3D printed. The coils were pressed into position and secured with tape. All coils must be aligned the same way. It is of great importance to mark the beginning and the end of each coil, as this plays a crucial role for the later wiring.
How the generator works
The magnets are arranged alternately all around. Thus, viewed from above, always south – north – south – north, etc.
Viewed from the side, the magnets must be arranged as follows: south – north – coil – south – north
I will try to explain here in simple words what happens in the coils. The „generation“ of the current is done by electromagnetic induction.
Electromagnetic induction is the phenomenon discovered by physicist Michael Faraday. It occurs when a change in the magnetic field near a wire or conductor loop creates an electrical voltage in that wire. Faraday found that movement or changes in the magnetic field of a wire or loop can cause electricity to be generated there. This voltage can then set an electric current in motion if there is a closed circuit. This principle that Faraday discovered is the basis for how generators work.
In principle, when the magnets cross the legs of the coil, the electrons in the wire are moved back and forth. This happens due to the alternating arrangement of the magnets. This further enhances this effect.
Now comes the part where it is important to have all the coils neatly labeled. The coils are wired in star connection (Y-circuit). This means that there is a common point where the coils are connected together. This point is called the star point or neutral point. If everything is labeled now, soldering the connections should not be difficult. It is important to remove the varnish of the enameled copper wire at the soldering points. I do this with a cutter knife. After soldering you get the three phases.
The output voltage of the 3D printed Generator generator is a three-phase current. This must now be converted into a direct current. This is done with a circuit called a three-phase rectifier (B6U). The circuit is very simple. Only 6 diodes are needed. On the left side in the picture are the three phases of the generator. The arrangement of the diodes in the circuit makes it possible to direct the current flow in one direction and block the current in the opposite direction. This results in a direct current.
I have tested the 3D printed generator extensively on my lathe. First tests were with an Osram H4 12V car light. I also measured the torque, voltage and current at different speeds.
The results of the first tests were not particularly satisfactory. The reason is that the magnetic fields are not „directed“. I solved this problem by adding metal plates to the outer sides. These metal plates help direct the magnetic field lines from one magnet to the next. This increases the performance by a factor of 2. It is therefore strongly recommended to install metallic plates.
Things that could be improved
I think the performance of the generator could be increased. Two points would help:
- Round magnets are not quite optimal. Rectangular magnets that extend over the complete legs of the coils would be better.
- The 0.5mm copper wire is also not ideal I think. This has a relatively high internal resistance and could be a little thicker.