Rotation Machine

This instructable will guide you in making a telekinetic rotation machine that demonstrates Faraday's and Lenz's laws. This works by using the phenomenon that changing magnetic fields generate eddy currents in a nearby conductor. These eddy currents result in a drag force and a lift force on the conductor and the magnets. This project will focus more on the drag force.

If you can get an electric motor that is strong enough, demonstrating the effects of the lift force will be possible.

We will make a model to show this phenomenon. In which a aluminium disk will rotate without touching directly being driven by the motor.

• 8 cubic neodymium magnets (12mm)
• 12V DC electromotor
• Power Supply
• Cables to connect the motor to the power supply
• Stand and clamps
• Aluminium Disks
• 3D Printer

For this project we will need to 3d print a few components:

• A mounting unit for the magnets
• A rod with an attached disk

Here you can download the printer file which can be used in the "Ultimaker 2" 3d printer.

After printing the magnet holder you can attach the magnets to it. The sockets are deliberately the same size as the magnets so that by hammering the magnets into the sockets they will be clamped. This does mean that it will not be the easiest of tasks.
The magnets are to be put in a halbach array to generate a strong magnetic field in the upward direction. The orientation of the magnets are rather important. You can follow these few steps;

• When the magnets are still stuck together, all in a row, draw a arrow on every magnet in the same direction to visualize the direction of the magnetic field. (This makes it easier to place them in the correct orientation.)
• Place the magnets in the holder like shown in the picture;
• In the image the crosses reflect an arrow pointing downwards through the magnet and the dots an arrow pointing upwards.

Since every magnet is pointed in a different direction, they will repel each other. Putting the magnets in can be tricky because they will push each other out of position.

It's advisable to put some glue in the gap that you want tot put the magnet in before inserting them. This way you will make sure they will stay in place.

We used a 12V DC electromotor and a power supply (shown in the image), but you can also use more powerful versions of these. This will only increase at the end the lift force on the disk.

To attach the magnet holder to the motor we used a small shaft sleeve to widen the motor shaft so we could clamp it in the center of the magnet holder. This will depend on the motor you use as not every motor has the same shaft thickness.

For powering the motor we used a 30V 1A powersupply. (ofcourse we did not use more than 12V as to not fry the motor)

We fixed the motor to the stand using a clamp. (shown in the image)

After the motor with the magnets are fixed in place we can place the aluminium disk above the motor. It is very important that the distance between the disk and the magnets is as small as possible. This will create a stronger effect.

We 3D printed the part that holds the disk as well. When this was printed we've put the disk in it and clamped it above the magnets to the stand. (see image)

After following all the previous steps the machine is ready to be used. By turning on the motor, the magnets will start rotating. This will also make the disk rotate, due to the eddy currents. Have fun!