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Building a model maglev train


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Hello everybody, I'm new to this forum site and I seriously need help. I'm a high school senior and for my senior project I have decided to build a model maglev train. I know a bit about circuits and electricity and magnetism from my physics course and from this, I have designed a model. My model consists of a wooden track that I built myself. I will use a small square piece of wood with magnets on the bottom as my train. In order to create the electromagnetic field that I need to make the train levitate, I have created a series of electromagnets by lining the walls and the bottom of the track with copper wires and connecting the ends of these copper wires to the negative and positive poles of a D cell battery. I figure that once everything is connected, the train will definitely levitate; however, I don't think that it will be propelled forward without me having to give the train a push. I'm thinking that I need Ac current flowing through the copper wires to push the train forward on its own. If anyone has any ideas about all this please let me know as soon as possible. Also, I have already bought all of my materials so if anyone thinks that it definitely won't work and I need to try something different, I would really appreciate that as well. Thank you.

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I'm thinking that I need Ac current flowing through the copper wires to push the train forward on its own. If anyone has any ideas about all this please let me know as soon as possible.

 

I found this in Wiki,

 

Maglev (transport) - Wikipedia, the free encyclopedia

 

Propulsion

An EMS system can provide both levitation and propulsion using an onboard linear motor. EDS systems can only levitate the train using the magnets onboard, not propel it forward. As such, vehicles need some other technology for propulsion. A linear motor (propulsion coils) mounted in the track is one solution. Over long distances where the cost of propulsion coils could be prohibitive, a propeller or jet engine could be used.

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Welcome to Hypography physics-fan! :hihi:

 

The wiki that Laurie linked to also has this to say:

 

Propulsion coils on the guideway are used to exert a force on the magnets in the train and make the train move forward. The propulsion coils that exert a force on the train are effectively a linear motor: An alternating current flowing through the coils generates a continuously varying magnetic field that moves forward along the track. The frequency of the alternating current is synchronized to match the speed of the train. The offset between the field exerted by magnets on the train and the applied field create a force moving the train forward.

 

This sounds a bit complex for your project, but it is doable I suppose.

 

Why not have a 90 degree piece of wood sticking up at one end of the track and coat it with magnets/copper. You could place your train against it, and when you powered the system, the magnets/copper on the back of the train would repel the magnets/copper on the "firing platform".

 

Hopefully that makes sense. ;)

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Why not have a 90 degree piece of wood sticking up at one end of the track and coat it with magnets/copper. You could place your train against it, and when you powered the system, the magnets/copper on the back of the train would repel the magnets/copper on the "firing platform".

 

Hopefully that makes sense. :D

 

I get what you're saying. Your talking about using an electromagnetic pulse to bump the model train forward, letting it glide on the track magnets.

 

"Firing Platform" ;) How 'bout - "Electrolauncher" or "Magnepropeller" (we'd better hurry up and copyright these terms :hihi:)

 

 

By the way - Welcome to Hypo p-f. :D

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I would attempt the ramp but I kind of have a track already built and I would prefer to keep what I have. I read what you submitted about the propulsion coils that line the track and I think that I would like to try that. I think that I'm going to wind some copper wires around nails to coil them, and then line the individual coils along the track. I will connect a 15 V power supply to the track, which will be "u"-shaped, to form a complete circuit. Does anyone think this will work? The track(--) will look like this:

 

| = |

| |

|__ __ __ __ __|

 

with the power supply(=) connecting and completing the circuit.

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You’re faced with 2 distinct challenges in making a maglev train: levitation and propulsion.

 

Levitation

The basic problem you’ll have to handle in getting a car containing one or more permanent magnets to levitate over a track containing an electromagnet (what I gather you track is) is the car’s tendency to slip sideways or flip over to align its magnetic field with the track’s.

 

This can be countered with a combination of car shape and side (“U shaped”) or even overhanging (“C shaped” ) guide rails, but simple, non-magnetic rails will result in the car being pressed against them by some of the levitating magnetic force, resulting in friction, defeating the purpose of magnetic levitation.

 

Therefore, I think you’ll want to consider wrapping coil wire to make 2 smaller version of the main track coil, and using them as side rails, and adding smaller side magnets to the car. Mounting the side rails above the track to form a “trough” in which the car rides, of below to form a “box” that the car overhangs on both sides are fairly equivalent.

 

If this seems too much work, you could try minimizing friction with the guide rails by simply using something slick, like plastic card stock. I just stuck together a gizmo of refrigerator magnets (the kind with metal magnets inside thick plastic bodies, not the flat, flexible cutout kind) and the scraps of punchout plastic ID cards, and while not frictionless, the magnet floated stably and with what felt like less friction than when just slid along on top of the plastic card stuff.

 

Note that, per Earshaw’s theorem, for any fixed configuration of magnets to support the car stably, the car must move. When still, some part of it will touch a guide rail, or, if there’s no rail, fall off the track.

 

Propulsion

The simplest way to propel the car is non-magnetically – a small electric or rubber-band powered propeller, for instance, or simply sloping your track to allow gravity to move the car. If your goal is to have both magnetic levitation and propulsion, however, you’ll need something more complicated.

 

If your track, either the bed or the side rails, consists of short sections of separately switchable electromagnets, you can propel the car by switching them (either off and on, or reversing polarity) in coordination with the movement of the car. With a well laid out switchboard control, I suspect this could be managed by hand. Alternately, if you have switches that can be computer controlled and programming skill, a software solution might work. Some scheme involving variable, very slowly alternating current to the (multiple) coils might work. I don’t think any propulsion scheme where the entire track coil is one circuit is possible.

 

Some final words: Halbach arrays. Though usually thought of in connection with the Inductrack maglev scheme, in which permanent magnets in the car generate current and magnetic fields in unpowered, conductive track coils, its advantages should also be applicable to a powered track such as the one you’re building. You can buy powerful little cubical magnets ideal for building a Halbach array (eg: from sites such as this one), though clamping and gluing them together is a dexterity challenge not to be taken lightly! ;)

 

Good luck, and post pictures :(

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  • 2 weeks later...

So I have tried to build the train. I have a piece of wood with magnets on the sides and underneath. I have a track that resembles a trough. Along the bottom track are electromagnets made from winding insulated copper wire around nails and attaching them to a 9V battery and a doorbell which is being used as a switch. i have two door bell switches, and every other electromagnet along the track is attached to the one of the bells. This means that when I press door bell #1, electromagnets 1,3,5,7 etc. are activated. The walls of my trough-track are lined with large non-insulated copper wire and act as side rails.Lastly, i have attached magnetic strips along the track to aid in levitation. After all of this...i still can't make it work?! I seriously need help seeing as the project is due really soon...

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Do you have a battery tester, or spare batteries that you could try instead? Clearly, a lack of power could pose a challenge. :esmoking:

 

 

Good luck. I'm curious to see what you've done.

 

Yes, I agree. I would not be surprised if it requires more power than you think. What type of batteries or you using, and how many?

 

I'm very curious as well. I think Mag-Lev trains are kick a$$. :shade: I wish we had state of the art Mag-Lev trains here in the states.

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So I have tried to build the train. I have a piece of wood with magnets on the sides and underneath.

 

Wood is quite heavy (unless you're using Balsa). What about a lighter material? It will require less power to levitate and move. :esmoking:

 

I have a track that resembles a trough. Along the bottom track are electromagnets made from winding insulated copper wire around nails and attaching them to a 9V battery and a doorbell which is being used as a switch.

 

I would recommend a 12V "lantern battery" (or two or three).

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Can you feel any magnetic force around your track/coil? :hihi:

 

As an alternative to batteries, you consider a small power adaptor. Most laptop power blocks are 15V, capable of a sustained 60+ W (4+ amps), and, of course, don’t run out of charge. They cost around $25 to $100, and at least a few are available at nearly any electronics store, or, if you’re lucky lying around in old laptop bags for $0.

 

:esmoking: As with any device that plugs into a 120V outlet, if you use one, be VERY CAREFUL you only attach your wires to the low-voltage DC output, not accidentally to the AC power supply input. :shade:

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I'd not try a transformer ("Wall wart") yet!

 

Measure the resistance of your electromagnet coils, and work out the current it will be required to supply first, or risk blowing it instantly.

 

Use the same current figures to (roughly) determine the life of your batteries. I bet it will be pretty short, since the magnetism is proportional to the current, so the resistance of the coil is low, to get lots of current through it off a single cell.

 

If you do the measurements, post them, I'd be interested.

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Hit your nearest hobbie store that deals in model trains! A model railroad transformer will generally give you low current AC and a pretty respectible amount of variable DC.

An added bonus is that the smaller units (like those used for "N", "HO" and "O" guage) are pretty cheap larger, high output units like those used for "G" and 1" scale are more expensive but really pack a wallup and can be used as a power supply for other projects. Of course if you have a junk pc the power supply from it could also be just the ticket. But personaly I'd recomend the former over the latter as you could use the AC for propulsion and the DC for levitation.

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