Rail Gun

yes

A railgun is a series of electromagnets which get turned on and off in sequence to propel the projectile... So…

No. What you mean is a coilgun. A railgun uses a different mechanism, like Wikipedia says:
"A railgun is an entirely electrical gun that accelerates a conductive projectile along a pair of metal rails using the same principles as the homopolar motor. Railguns use two sliding or rolling contacts that permit a large electric current to pass through the projectile. This current interacts with the strong magnetic fields generated by the rails and this accelerates the projectile."

the car wont follow the foil, unless you mean to make slots in wood or something and line it with metal. otherwise you just need to add somekind of switch to increase/decrasese voltage

duhh thats the whole point of a *slot car* but ya I know someone who is writing an equation to determine the resistors needed, and if u already know, we would like around 32-36 volts now cause we used 2 9 volts and it was pretty wimpy.

Yeah but mains is ac but bateries are dc...

 You can reverse the wires to the battery or you can reverse the poles of the magnets...either way it will go in the oppose direction.  

reffer to this picture. looking from the power source, if the (-) is on the left and (+) on the right, it will go forward.

 I understand the force diagram that you have here however for this type of projectile i dont think it is the whole story.  With a classical rail gun this would be true, but  if you reverse the magnets the projectile will move in the other direction (current still flowing in the same direction therefore the force should be the same.  I cant wrap my head around how this is working using the magnets..anybody got any ideas?

 well, its not magnets per se. its an electromagnetic current that creates a magnetic field. the magnetic field creates pressure behind the projectile in the same way a regular gun does with gunpowder. however, this design is different. rather than creating pressure behind the projectile its just repelling the magnets down the strips.
sorry if this is just re-explaining something already known.

Thanks for the post!  I understand what you said however for this case its weird because for the design to work either you would need Both North poles facing out or both south poles facing out.  Having south out on one side and north out on the other will not allow the "projectile" to accelerate.  These field are emmited from the north and would partially travel through the nail and return to there south poles.  I assumed the B-field that is created by the rail is interacting with the field emitted by the magnet..therefore there is a component of B-field from the rail that is closer to parallel with the rail rather than the classical perpendicular to the rail they way a normal rail gun works...the problem I have is when i analyzed the direction of current, applied the right hand rule and  compared it to the inaction with the North or South pole that was facing out..the projectile accelerated in the opposite direction that it should of.   This confounded my  reasoning.  Im out of school for the summer till i start Diff E Q  so i will have a bunch of time to get to the bottom of it an hopefully will be able to put up a diagram that shows the underlying physics of this...Although making this is extremal easy... Its underlying physics seem subtle.  Or mabey i have overlooked something.  Thanks again for your post

what if there was a black out...?

Then you wouldn't be going anywhere fast.

wouldnt matter if there were a black out. They could have it reversed and have the road be a big magnet and the wheels be made of metal and have an electrical charge leading to them and you would increase volts/amps to go faster and decrease it to go slower.

yes that is very true this is an awesome instructable!

true true

monorails do this already, like millenniumman said, and if we did this on roads, it would require more aluminum than you could probably find in the entire solar system... and would need to be continuously replaced as it wore down. Although my question is, why on EARTH ARE YOU TOUCHING THAT THING DIRECTLY?! Iron conducts electricity quite well... wouldn't you be shocked by manually placing that thing on there?

A)he used ALUMINIUM foil not iron B) Its a nine volt PP3 battery. you are not going to get a shock from that.

just a funny taste when you stick it to your tongue :)

Done that before and got a shock...

If there sere only such a thing as a Monorail... lol

Wow that is actually not a bad idea. Three problems though, one all the roads in the world would have to be changed over, there would need to be a way of monitoring electricity consumption to charge people (Electricity isn't free) and what if wildlife or a stupid person walked onto the road, would they get toasted? Creative Idea though.

how about a train then

not a bad idea. there is still problems though

ooooOOOOOooOOOooooOOOOOHHHHH!!!!!!! Thats a good idea! Just need a way to guide the sucker. And away to make it more efficient than a monorail/light rail/other rails.

the rails will guide it

yea, can't recall what I was thinking about there...lol

hence the phrase "theoretically"

Exactly, but you have to admit its a cool idea.

yea, it would cost too much and probably take a lot of maintnance, yada yada yada......

It would add alot of entries to the Darwin awards. I can see it now...... People being dared to lick the road or pee on it or other things I know I can`t post on here.

lolz

ceramic magnets are way weaker than a neodymium-iron-boron, or samarium-cobalt magnet of equal volume, if you are having difficulty finding Neodymium or samarium Magnets there are small ones in the toy Magnetix, or Good quality earphones

also, I may be wrong, but ceramic magnets might not conduct electricity and will not work as the "projectile" has to be conductive to complete the circuit.

I'm pretty certain that a magnet doesn't have to conduct electricity on its own in order to react to an electromagnetic wave... magnetism is magnetism, if something is magnetic, no matter how well the material conducts electricity, it will always be magnetic

Yes, but then you dont have a circuit and electricity wont flow and it wont work. It is not the magnetic properties of the magnet that are needed but that the projectile completes the circuit.

I'm SO sorry it took this long for somebody to answer you; at these voltages and amperages it is definitely required to use neodymium. I'm sorry. If you don't want to buy any from the online stores, chances are you can find them at your nearest craft supermarket. If you wanted to use ceramic, I'd advise using capacitors.

umm... that's never going to work. A lot of people with a lot more electronics knowlege than you have been able to make pretty weak devices, your oversimplified design seems both extremely dangerous and doomed to failure, I'm sorry but you'll never be able to put nails through you floor.

Plus something does have to be complicated to work. If it is, it just creates opportunities for something to go wrong. And it does not have to work the first time. There is a learning process to things as well the trail and error process. The only way that what I have just said could be wrong is if you were GOD. People make mistakes. Life goes on.

That was my first design I have built and tested a refined version and it is doing not to bad so far. It needs to be tweaked more but I have included a diagram in the shortcut below. (not drawn very well)

sorta got to agree with popcorn man on this one though.. railguns arent simple they have lots of current and are lethel but, thats obvious and hopefully you alredy know that. also to have enough current to send nails into cement, no way in hell-sorry, but if you hook it up to your main house power line about 100-200 amps; (like what your dryer runs off of) you might be able to do some serious damage. 

Lol 1 year later reply and he responds within half an hour

You need to run it at closer to 1000 amps.  The higher the more power.  But also the larger the projectile has to be as to not completely melt.  Mine runs at 600 I think.  I don't really care.  If it works, DON'T TRY TO FIX IT!

you have no idea what your doing... but good luck anyway

Says you.  I have seen ones that are smaller then a chainsaw that will put a nail as big as your pinky finger into and through cement.  They run off 120vac power.  They work, mine is toned down, and it works.  Notice how that was posted almost 1 year ago.  I tried this, works fine shoots a 4 inch nail easily into cement.  SO SUCK IT!

If you hook the microwave transformer up to wall current you will get around 1200 volts. I use a microwave transformer and put 12 vac into it and get close to 120v out of it. I didn't notice what brand microwave I got the transformer from so I can only tell you the ratio of the one I'm using. Thing is to BE CAREFUL I hope you have a multimeter that will scale up to 1200 volts. I had to buy a special HV leads for my meter.

Yes I get that but a microwave transformer is used the other way. You are supposed to put 120 AC v through the primary to produce something like 12 v and 60 amps out the secondary. You sent the 120 AC v through the secondary winding and got 1200volts out the primary which should be expected in this situation. You should try it the other way and you get 60 amps with low volts but be careful 60 amps is more than enough to kill you.

Microwaves use high amps going through a copper coil around a carbon ( I think its carbon but correct me if I'm wrong) to produce microwaves for cooking. Look at the stickers on the microwave and it should say that.

Microwaves supply the magnetron with a (generally) 2KV 250mA (0.25A) to 1A transformer. When wired with the primary to mains, the output is 2KV. Before the magnetron, there is also a capacitor/diode voltage multiplier, also known as a Cockroft-Walton generator. This steps the voltage up to 4KV at 0.25A (pulsed DC).

That seems unusual as the tens of possibly hundreds of microwaves I've torn apart I have tested as low voltage and high amps. That is also why they have fairly thick cables running to the magetron. Normally Hv devices use small thin wires with lots of insulation.

I probably accidentally had them backwards. *OOPS*

Yep, you did. But it's fine. They're cool backwards, too! What's really fun is to make them into high amperage by modifying the secondary winding. Congratulation on your find of that transformer.

If you have any info for helping me with a fly back transformer I would love to hear it cause my does work worth squat but it is out of a very new working CRT monitor. Help appreciated Thanks

I've been working, lately, on building some Tesla Coils. I've already finished one, and its estimated voltage output was about 250,000 volts (250KV). It was run off of a 3000 volt transformer. The wire I used for my secondary coil was 24 gauge, whereas what they use in microwaves seems to be somewhere around 20 gauge, with much thicker insulation, in order to keep voltage from passing from one wire to another. When you have high amperages, it has a tendency to heat up the wire it's traveling through, whereas high voltage doesn't have that problem. If you have a transformer that burns up, it's most likely from over-amperage, rather than over-voltage (that is, unless you made said transformer yourself, like I did with mine...).

Also you wouldn't happen to know if there is a difference in age of the microwave and the output of the transformer because I take apart alot of the old dinosaur big micro waves, the ones the size of a chair practically. I like them cause the transformers are 30lbs or so.

You know, I'm not sure. If the windings are substantially bigger, and the wires are substantially larger, there's a great chance that the power throughput is much larger, as well. A method of telling that works well is to put a multimeter measuring AC amps on the line-side (NOT THE OUTPUT(!) OR YOU'LL RUIN YOUR METER!) and test the amperage. You then multiply the amperage by the voltage (120, in America) and if the sum is over 1000, then it's a pretty powerful transformer. If it's not over 1000, then chances are the transformer is just much more sturdy and will put up with more abuse; after all, if a microwave can survive this long, it must have a strong transformer and magnetron to put up with the torrential usage.

The windings are extremely large compared to new microwaves, as well the wire that the windings are made up off are at least 10 gauge wire for both primary and secondary windings (Input and Output).

Ya, but I could be wrong about the whole high amps low volts thing but I've checked many websites about this and there is like 50 50 split of Hv or High Amps. But they do work both ways.

It depends on how you wire it. But the way that they're made to work, the transformer puts out a higher voltage than what's put in. The amperage is still high on the output, due to a high number of VA, as I've stated in one of my previous posts. The amperage is about half an amp on mid-large-sized transformers.

Oh yea I was going to add that you get two great magnets from the magnatron found in every microwave. With twenty of them all stuck together they form a big tube that will knock out the color of a tv from many feet away.

Neodyiumum magnets the size of Just one of those ceramic magnets Can stuff it up from an equal far distance

Ya I've seen the two magnets off the magnetron. I don't like taken them apart too much cause that's what creates the radiation waves.

The magnetron only outputs the microwave radiation when the transformer is attached and running.

Safety first. I would like to reproduce later on in my life and live past 16 as well. But i know what your saying and i did realize this but I wasn't sure cause i never researched it much.

Yeah; the magnetron radiation is only electricity. It's only as bad for you as radio waves are once they've turned off. You don't see anybody getting poisoned from a microwave because the microwaves don't actually put out particles, but, instead, a frequency that resonates with water and is useful for cooking different foods.

You are partially correct, however, all electromagnetic radiation has a resonating frequency. The magnetron creates this from exciting particles in the resonating chamber. If the magnetron had a current applied to it you could possibly get burned or damage your eyes. be very very careful please.

Ya but one, radiation is bad cause you can get cancer or something(I am not a radiation scientist so my knowledge here is very limited and non scientific). Also the human body is 80% water so....well I think you should get what happens next. Actually in Calgary AB where I live there were some kids who broke into a house and microwaved the occupants cat, it was in the news awhile back. Very gruesome.

Or a 120 AC v house plug, microwave transformer and many big capacitors. This works as I have made one using this method. I'm looking for a gun shaped case to put it in to finish it but at least it operates. The case is going to have to be HUGE.

Is is a rail gun in the sense that it use huge amounts of amps or that the projectiles used for a real rail don't need to be magnetic but it is a good representation of the theory behind what is happening.

Ive heard that if you take 1000 of those glue them to a trash can and mount that to concrete you can pull a car off the road. That is if they stay on the trash can and the trash can is cemented to the ground and doesn't move.

inches?

no centimeters

Actually, you do need the neodymium magnets. The torque generated is dependent on the strength of the magnetic field. The problem is that the nail end is too narrow to be safe. It is too critical on the flatness of your cut. A short length of narrow copper or aluminum tubing cut with a pipe cutter would give a flat surface on each end that would minimize the chance of the magnets jumping off the end to get to each other, with your fingers in the way.

I second the familiarity of this. You could have at least credited scitoys.com for the original directions.