33 replies to this topic

[coastercrazy10]

It wouldn't. You can't create energy out of nothing. It would either have no effect or a braking effect. I know you're not being totally serious, but just to eliminate any confusion, a launch is impossible without inducing a current outside of the car (i.e. electromagnets)

-Ben

[LaMbChOpZ]

Aaron: that could also work. Might be a bit of an issue with clearance with a copper fin but it's worth a shot!

For now if this works out I would stick with the cubes but in time I would love to create cars that have fins on them to make them even more realistic.

So far the speed from the lift hill and predrop is creating a substancial amount of speed, so there will most likely be Neo magnets on the pre-drop and possibly throughout the ride depending on how hard it is to keep control on the velocity. More to come about the magnets once they come (I still need to order them).

[Jogumpie]

A copper fin inside a magnetic field is exactly what is done in the real world. These are eddy current brakes, or what we know as magnetic brakes.

http://student.fizik...ed Currents.pdf

Read through this lecture of Feynman, he's got some marvelous information in there. Search for the text part that is about figure 16-10 and 16-11. By using two magnets you can create a unified magnetic field between them (again, look at those pictures). When you insert a piece of copper in there, eddy currents will be created, which circle through the copper. The faster you insert the copper into the field, the bigger the currents will be. These currents provide a braking effect; they try to hold back the insertion of the copper into the magnetic field. Apply this as magnetic brakes and you get a viscuous braking force; the faster the copper fin moves, the more braking you will get.

The whole 'place some magnets on the train and on the track' seems like an idea that's destined to fail.

[RNB]

Launching is possible, with electricity.

1. Add 2 metal stripes on the track (not too long, there have to be very much of them!)
2. Add wires between 1 stripe, going to a battery, wrap it multiple times around the magnet and attach it to the other stripe. (don't make a closed circuit!)
3. Add 2 metal joints at the bottom of the car. Make sure that when the train is running over the stripes, that the joints complete the electricity circuit.
4. Redo 1/3 quite some more times!

I haven't tested this, but according to my science teacher it should work.

[coastercrazy10]

The whole 'place some magnets on the train and on the track' seems like an idea that's destined to fail.

It will not be as effective as a properly engineered fin braking system, but it will work, seeing as another member has already done something similar with bar magnets.

Launching is possible, with electricity.

1. Add 2 metal stripes on the track (not too long, there have to be very much of them!)
2. Add wires between 1 stripe, going to a battery, wrap it multiple times around the magnet and attach it to the other stripe. (don't make a closed circuit!)
3. Add 2 metal joints at the bottom of the car. Make sure that when the train is running over the stripes, that the joints complete the electricity circuit.
4. Redo 1/3 quite some more times!

I haven't tested this, but according to my science teacher it should work.

This will cause energy loss from the friction of the contacts. This is close to a LSM launch, which Tyrant worked on some years ago:
http://www.sscoaster...sm-launch-3750/

-Ben

[RollerManiac]

He is saying that using electromagnets to generate an Eddy current will be more effective. However, I am certain that permanent magnets can create a breaking effect. If you align the negative pole of a Neodymium forward in the car and the negative poles of the Neodymiums on the track facing the car as it approaches (or the same with positives), then you can cause the car to slow and/or stop depending on the amount used, since all forces on the car are facing its approach. I've attached an illustration so you can see what I mean:


You will probably need some pretty powerful magnets though, and be sure they're not going to snap together when the cars run over them. That could damage the magnets and the track too.

-Ben

I've been thinking about a V2 recreation with LIM, and this is exactly what I was thinking about. How about an eddy current magnet?

[LaMbChOpZ]

^I think Tyrant tried that before and I think it either didn't work out or he just stopped. There's a few threads on SSC about it, but I don't remember where they are. I last read through one a few days ago.


Oh yes, btw, no matter if these Neodymium Magnets will work or not, I am more than willing to spend $20 on magnets to see if they work. I will hopefully order them tomorrow morning or even tonight depending on my parents. If I get them tonight, they won't arrive anywhere from August 19 to August 25th which is pushing the SH deadline...

Oh yes, bad things about Neodymium Magnets:

**CAUTION**

SHOULD NOT BE USED AROUND PEOPLE WITH PACEMAKERS AND ELECTRONIC EQUIPMENT.

Uhm, NXT, great....

[coastercrazy10]

The danger of Neos is wiping memory of certain devices. However, a lot of magnetic force is required to wipe, so as long as you keep your NXTs and other electronics a foot away or more from your Neos then you're fine.

The LSM launch thread is linked in my previous post in the thread for reference, if you're interested RollerKid.

-Ben

[LaMbChOpZ]

^The magnets I will be ordering within the next day or so are 1/4 inch small cubes that will be in the track and in the custom car. I'm going to have the magnets on one side of the coaster (due to where the brake runs are) and the NXT is in the base on the other side of the coaster well over 1.5 feet away. Just wondering, but will the magnet's size affect the distance or is it like a universal guideline?

[RollerManiac]

Is there anyway to make a shuttle mode launch with these magnets?

[LaMbChOpZ]

^This has little to do with the topic of the forum. If you're willing to risk the money, I guess go ahead and try it.

[pkiknex25]

^^ You would need a circuit connected to the magnets to reverse the polarity for acceleration through reversing currents.

Honestly, I don't see 12 and 13 year olds pulling this off. It's great you are taking interest, but it takes a lot of knowledge and skill to put it all together.

[coastercrazy10]

Again, a launch cannot be built from permanent magnets, ceramic, neodymium, or otherwise. Energy can only be dissipated by a static magnet. You would need electromagnets to produce a launch, and a shuttle launch would be even more complicated and will require the use of (ideally) a microcontroller but can also be done with servos, etc. There is no easy solution for a magnetic launch; if there was, it would have been created already.

Chopz: I'm just giving a general guideline. Keeping the magnets as far away from other electronics as possible is ideal, but with moderate-strength Neos a foot should be plenty of space. Most electronics would be damaged around 1-2 inches (or less, depending on strength) unless the magnets are extremely strong, but better safe than sorry...

Also, I agree with Kevin to an extent - a braking system isn't out of the realm of possibility for someone inexperienced with electronics and magnets, but a launch (LIM or LSM) is a rather complex problem that requires a reasonable amount of electronics knowledge and engineering skill.

-Ben

[LaMbChOpZ]

^Well I was rethinking the N-factor of the magnets now that I've seen a video showing 2 big N-42 Magnets (I think they were 2in by 3in by 1in wide) and they easily crushed a few chicken bones. The ones I was going to order were [EDIT:] 1/4 by 1/4 by 1/4 (inch) at N40. [/EDIT :p] I don't think it would do the same since I know the size does affect the "attraction" of the magnet but I'm still a little hesitant but I know they could easily do the job.