# Simple MagLev Train

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## Introduction: Simple MagLev Train

One popular science experiment we are often asked about is the magnetic levitating train. We built a basic version of this experiment to highlight some of the challenges and solutions of a project like this. Of course, once you figure out the basic setup we've built here, you could let your imagination run wild and build some really cool tracks!

This simple craft can help you understand the basic magnetic principles that go into MagLev trains. It's amazing that with the use of magnets, a train can be travel at over 300mph!

In this article, we'll go through some basic track construction, as well as provide some challenges and of course some technical magnetic info!

Materials needed: Neodymium magnets, Lego's (or other building blocks), and superglue...that's it!

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## Step 1: Track Construction - Decide on Design

The first step when constructing this basic MagLev train is deciding on your design. Since we created this just to show you the basics behind it (not to show off our artistic ability), we chose a simple, 5 inch long, straight track. We used 5 BX041 magnets for the track.

## Step 2: Track Construction - Gluing

Once we decided to go with our simple track, we simply glued those BX041 magnets to the top of the Lego's.

The important thing to keep in mind with this step is all of the magnets need to be facing the same way. For example, all of the magnets need to have either the north pole facing up, or the south pole. This is important because MagLev trains work on the basic principle of repelling magnets. It is important that all the magnets be orientated the same way, so that you know which way to orient the magnets on the train as well.

We used our Electronic Pole Identifier to make this process pretty simple.

For tips on how to effectively glue magnets, check out this article.

## Step 3: Train Construction

Another pretty simple step, but remember to keep in mind we need the magnets to repel. We chose a longer Lego piece to add a bit of stability. You can also chose to used different sized magnets, depending on what distance you want the train to repel from the track.

As you can see from the chart we included, two BX041 magnets will repel a pretty visible distance, even with some weight on them.

Once the magnets are glued to the train, you need to add some stability to the repelling magnets. Repelling magnets are highly unstable, magnets do not want to repel. Adding the right amount of weight and stability can help you achieve stable levitation.

Our stability came in the way of adding Lego's underneath the train. These legs hug the track closely, but do not touch the track. This adds side to side stability. Using two magnets on either side of the long train piece adds stability front to back. We now have a stable levitating train!

## Step 5: Add Weight If Necessary

We found that using the BX041 magnets, the train repelled pretty far away from the track. This could potentially make the train unstable. We added some bolts to the side to weigh the train down a little bit, which also decreased the repel distance. This added some better stability to the magnets.

## Step 6: Challenges and Solutions

The first challenge is to make sure you are orientating the magnets on the track and train so that they will repel. As shown in our picture, and as we discussed earlier, the magnets need to be oriented the same way in order for the train to work. You will find out pretty quickly if the magnets are attracting! Like poles will repel each other, either north to north or south to south.

The second challenge is stability. As I've said, repelling magnets are very unstable. Magnets don't want to repel, so they will do whatever they can to attract. In order to stabilize the train, we added weight, a longer Lego at the top, and some legs on the side. You may find a different way to stabilize the train...let us know what you come up with!

In the video, we show this instability and how we remedied it.

There you have it, this is about as simple as you can get, but a fun craft and science experiment! Let us know how this works for you and share some cool pics of your train!

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## 23 Discussions

What are the simplest materials do we need to make a model of a train???

Where would I get the small BX041 magnets for the train project?

do you have a kink for the magnets

using this for a science fair project, do you think you could show me how to make a 90 degree turn?

Left out some stuff. The system was dead quiet except for a little hum. It was about \$150,000. I'm thinking their stuff is cheaper two decades later. The restaurant was called DIVE! in Culver City.

Ok getting on my flight. I'll post details later.

There is a company in England that makes maglev curtain systems. I used them 18 years ago for a restaurant here in L.A. that was themed in a submarine concept. One of the elements I built was an overhead track that carried 5 weird steampunk models of submarines. They weighed about 10kg and about a meter long.

The client knew that any standard track system would be far too noisy. Nobody wants to eat with metal carriers clanging around overhead.

The mag curtain carriers are very cool. They use lots of little electromagnets in the carriers that wrap around a standard heavy duty steel track used in theaters to carry scenery and soft goods. The tech is proprietary and is patented but you can get the concept from their specs.

The company in the UK has a name that I can't wrench out of my brain. They do rigging for giant curtains in theaters and solid panels for large spaces that reconfigure into multiple rooms. Google using curtain and maglev. I can't do this myself at the moment but I'll look it up later.

Since it's almost 2 decades the tech is likely far better now.

Another way for low friction is super cooled sapphire plates and neodymium magnets. Look it up really cool!

An idea for you: use 2 repel track with a wider train, add a center track to be attracter. The center will hold the train on the track.

It will not. No matter how you set up permanent magnets, the result will not be stable. At lease one axis will be unstable, and the train will "crash" unless it is mechanically constrained by wheels, or actively constrained by position sensing, control circuit, and a coil set, or constrained by diamagnetic materials (which require cryogenics to get practical levitation forces).

https://en.wikipedia.org/wiki/Magnetic_levitation

https://en.wikipedia.org/wiki/Earnshaw's_theorem

id love to this version! sounds good for stability/centering.

You cannot possible achieve static stability with any arrangement of magnets. The train has 6 degrees of freedom, of which 5 must be constrained by the track The system you show is unstable sideways (both in 2 degrees of rotation and laterally) which is borne by rubbing between the legs and the sides of the track. You have several choices to achieve stability. One is to add electric power, position detection, a control circuit and coils to stabilize the unstable axes (I think that's how the real maglev trains work). The disadvantage is if the control system or power is lost, the train "crashes". Most "real trains" have "emergency touch-down wheels" for this reason. For example, the Levitron levitating lampshade uses this technique as shown here:

The Levitron lamp stabilizes 2 horizontal rotational axes and (1) vertical translation passively, and actively stabilizes the (ordinarily unstable) 2 sideways axes with hall effect sensors, a pair of coils, and a microcontroller. Rotation about the vertical axis is unconstrained, allowing the lampshade to turn. If you unplug the lamp, the shade falls.

A second way to achieve stability is to have a track made of aluminum (or other good conductor) in a U-shape and launch a magnet into the groove of the U. If the speed is high enough, the magnet will levitate. The forces governing it are similar to those on an airplane; a minimum "airspeed" being required to support a given load. (The train can "take off" from wheels just like an airplane as it reaches "flying speed"). Drag force is higher than wheels, but comparable to an airplane (lift to drag ratio somewhat greater than 10). This scheme would be the most practical way (of the 3 I present) to build a model train that illustrates the principle. An array of "kicking coils" along the track could keep the train going, or you could start from a ramp on wheels.

A third way to achieve levitation is to have a magnet for one member and the permeability of the other member be less then 1. Pyrolytic graphite can levitate over a magnet using this principle. At the following link you can purchase a kit for \$14 that shows this.

http://www.envisionlabs.com/shop/viewitem.php?prod...

But this is too feeble to carry practical loads, even for a model. If you substitute superconducting material for the graphite, then you can levitate practical loads, but that requires cryogenic cooling of the entire track, or magnets on the entire track with cryogenic cooling of the train car bottom.

Won't the "train" slow down a bit when it's hovering over the tiny gaps that are between the magnets?

It might a tiny bit, but the strongest magnetic field of a magnet is actually at it's edges, so from edge to edge, the field would carry the train over.

Very cool!

Maybe adding a grade so the train would 'gravitate' to the end of the line. Placing an opposing pole there to send the train back up the grade could create a sliding perpetual motion kind of effect, back and forth.

Neat-O!

Unfortunately, magnets won't work like that, although that would be cool! Once the magnets reached the end of the track, the repel force wouldn't send the train back up the grade, the train would stay stationary at a certain distance from the repelling magnet.

Um, no.

It's low friction, but air resistance would eventually slow it to a stop.

I'm curios, is there any force advantage to ever sligthly "stair stepping" over a flat track with an incline?