Building a simple electromagnetic train is part science and part magic! Using a few supplies, kids can build a copper coil tube that will propel their battery train to move on its own! It is all very cool and a really fun STEM activity or science fair project starter for kids of all ages.

Build a Magneto-Electric Train

One of the things I love about this simple science experiment is that although it is easy to make and fun to play with, there is unlimited learning experiences for kids of all ages and grade levels. Adults will be challenged with these concepts too. It is all so fun to explore the science behind the play!

Related: This is one of over 50 science fair project ideas

Once you have built your electromagnetic train, be sure to stock up on batteries because it is really fun to play with and those batteries don’t last forever…

–>Did you know we wrote a science book? Check out all the fun…101 Cool Science Experiments to be exact {Giggle}.

Note of Caution: This simple science experiment uses neodymium magnets which are small and very strong which can be a safety hazard. The magnets absolutely have to stay out of kids’ mouths and never swallowed. Younger children need constant supervision while playing with the train because the magnets are so strong and there are batteries and copper wire with sharp ends.

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Supplies Needed

• AA Battery or AAABattery – it can not be dead!
• Fat Marker or something cylindrical that has a larger diameter than the battery you are using – we used a Crayola Washable Marker
• Copper Wire – the longer the wire, the longer your train tunnel
• Round Neodymium Magnets – these are very strong Magnets that have a diameter smaller than the marker

Related: Need more fun magnet experiments?

Directions to Make An Electromagnetic Copper Coil Train

Step 1

Using the marker as a guide, wrap the copper wire tightly around to create a circular tunnel. The coil doesn’t have to be perfect, but you want to avoid areas that have a large enough space that could disrupt the batteries path through the coil tube.

Keep winding and winding the copper wire around the marker and pulling it forward when you need more marker space to wind. You will be creating a long copper coiled tube.

Step 2

To make the battery and neodymium magnet train, we placed three magnets on each side of the battery at the ends.

Does it Matter Which Way You Put the Magnets on the Battery?

This question could be your first experiment! Will the magnet position change the way the train moves?

–>Spoiler Alert: Yes! In fact, the magnets on each end need to be positioned so they are pushing away from each other.

If you line the magnets up so the two of the same poles face each other, the magnets will push away. This is called repulsion. Opposite poles attract each other, but similar poles repel.

DK Find Out, Science of Magnets

Step 3

Position your long coil of copper “train track” so that there aren’t any sharp corders or twists creating a clear path for the battery train.

Place the battery train inside on one end and let go…

Will the Battery Train Go In Both Directions?

This is another fun experiment you can try. Insert the battery train in one way and then try the other. Do they both work? Or is your electromagnetic train a one way train?

–>Spoiler Alert: Your electromagnetic train will only go in one direction because of the magic of magnetic poles.

Watch Our Electromagnetic Train in Action [Video]

Why Does the Battery Move Through the cOpper Coil?

The answer to why does the battery with magnets move through the copper coil is something that could be explored much deeper because the relationship between magnetism, movement and electricity is a complicated one!

Between electricity, magnetism and movement form a “super cosmic team”. With Movement and Magnetism you get Electricity. With Electricity and Movement you get Magnetism. With Magnetism and Electricity Movement is obtained.

–Quora, Quote attributed to Michael Faraday in 1831

Faraday’s Law

Michael Faraday was a physicist that made a big discovery in 1831 that is now named after him as Faraday’s Law. He found that changing a magnetic field can cause create voltage. And the bigger the change you make in the magnetic field, the more voltage.

Lorentz Force

Hendrick Lorentz was a physicist that figured out something about magnetic fields a few years later in 1895 that can help us look at this deeper.

Lorentz Force is the force that is exerted by a magnetic field on a moving electric charge. So it is the combination of electric and magnetic force on a point charge due to electromagnetic fields.

–Medium Youngwonks, What is the Lorentz Force

Homopolar Motor

And all these discoveries lead to the understanding of something Faraday had discovered years earlier called a homopolar motor which is a very simple motor built to use direct current powering the motor in one direction. Another homopolar motor can be built with copper wire, a battery and strong magnets…sound familiar?

The magnet’s magnetic field pushes up towards the battery and the current that flows from the battery travels perpendicularly from the magnetic field. This causes the creation of a force perpendicular to both the magnetic field and current.

–California State University of Bakersfield Department of Chemistry, How to Build a Homopolar Motor

Putting it All Together

When the battery with magnets on each end is placed inside the copper coil it completes a circuit creating current to flow through the coil which then creates a magnetic field.

What happens: the “virtual bar magnet” created by the current flowing through the coil pushes the magnet in front and pulls the magnet behind. Of course the battery between them gets taken along for the ride!

–Skulls in the Stars, The Mystery of the Magnetic Train

Learning More About Electromagnetism

We were inspired by the viral video that was circulating that showed what they called the World’s Simplest Electric Train:

I think the most comprehensive and understandable description of why the battery moves through the copper coil is from Skulls in the Stars if you want to dive into all these concepts deeper.

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What did your kids think about this STEM activity? Did they love building their own electromagnetic train out of copper wire, magnets and a battery?