Posts: 1
Joined: Tue Sep 07, 2021 12:17 am
Occupation: Teacher

Maglev Trains HELP

Postby mike84 » Tue Sep 07, 2021 12:31 am


I'm wanting to make the maglev train as shown on the website.

I have purchased the magnetic tape ready.

I know about magnets and how they repel and attract depending on the poles. I'm however stuck as to how to achieve this with the magnetic tape that I have purchased to make the train. On the equipment list for 'Build a maglev train' it just mentions buying magnetic tape which I have done. But the tape is attracted to each other when cut in strips and not achieving the desired affect of levitating the train (buy repelling each other). What have I done wrong or what tape do I need?

Any help or advice will be greatly appreciated.

Posts: 357
Joined: Mon Oct 03, 2011 12:26 pm
Occupation: US Air Force Space & Missile Operations

Re: Maglev Trains HELP

Postby theborg » Wed Sep 08, 2021 8:08 am


Thanks for your question. The project has a FAQ section that runs you through troubleshooting this issue that you should review for greater detail. However, here are the possible issues.

1) The magnetic strips on your track might be too close together causing them to not be aligned with the magnetic strips on the train car. If this happens, move the magnetic strips on your track farther apart.

2) Your plastic angle pieces might be too far apart. This gives the train car too much room to shift side to side, and it can be pulled down to the tracks instead of repelled. If this happens, move the plastic angle pieces on your track closer together.

3) The least likely possibility is that the polarization (which way the north and south poles face) of one set of your magnetic strips has been reversed, meaning the non-adhesive sides of the strips are attracted to each other instead of repelled. If the magnetic strips are touching each other and their edges are aligned, you will need to repolarize two of your strips. Only do this after you have tried steps 1 and 2 to make sure your spacing is correct. You can use a compass to check the polarity of the magnetic strips by holding a compass up to one of the magnetic strips on your train car and determine if the red tip of the compass needle points towards or away from the magnetic strip. Do the same thing for one of the magnetic strips on your train track. If your results are the same for both strips, then your strips are polarized correctly and should repel each other. If your results are different for both strips, then you need to re-polarize one set of your strips.

I hope this helps,

David B

Site Admin
Posts: 423
Joined: Mon Aug 22, 2016 4:39 pm
Occupation: Administrator

Re: Maglev Trains HELP

Postby AmyCowen » Thu Sep 09, 2021 1:30 pm

I wanted to follow up to confirm that you will likely need to repolarize the strips using a magnet, as David mentioned. The directions for checking this and then doing this are in the FAQ ("Help" tab) for the project.

Many magnetic tapes are not monopolar. (And most of them don't say one way or the other.) For this project, the magnetic tape does need to be monopolar. If your strips are attracting to each other, and all other things David mentioned have been checked, it is likely the tape is multipolar or bipolar. (This is common for many magnetic tapes.)

Repolarizing them, as directed, should solve the problem so that the strips can be used for the floating train project.

Science Buddies

(Note - directions for the project are also being updated to more clearly explain this about the tape used in the project.)

Posts: 1
Joined: Thu Oct 07, 2021 9:35 pm
Occupation: Parent

Re: Maglev Trains HELP

Postby Pendel » Thu Oct 07, 2021 9:48 pm

I have a similar question as to Mike. I have tried using the neodymium magnet to switch the multipolar magnetic strip to have the same polarity through the face of the strip and I am having issues. Can I use an electromagnetic coil over the magnetic strip and have all the polarities shift accordingly or would the internal multipolaritary of the strip just flip orientation and I would be stuck in the same situation?

I.E. what I have is a NSNS and I want to see if a DC powered Electrical coil will be able to change the polarity to either N or S on the entire face.


Posts: 482
Joined: Mon Aug 12, 2013 2:41 pm
Occupation: Science Buddies Staff

Re: Maglev Trains HELP

Postby bfinio » Fri Oct 08, 2021 3:50 am

If you currently have NSNS, then a strong enough magnetic field (whether it's from a neodymium magnet or a DC electromagnet) should repolarize the strip to either NNNN or SSSS, it won't "flip" the fields to SNSN. If you are having issues with the neodymium magnet though, I would try again and make sure you slowly go back and forth completely over the entire strip. A larger magnet will make this easier, but I did it with a fairly small one (that was narrower than the strip) and it worked fine - see Figure 16 at the bottom here: https://www.sciencebuddies.org/science- ... eight#help

Return to “Grades K-5: Physical Science”