Handheld Coilgun

[Guest026]

I'm thinking about making a railgun but apparantly they can kill me so I'm probably going to make a pistol-like coilgun. I need to know what kind of wire I need for the coils. Oh and how do the coils in a multi-stage gun go turn on and off by themselves? and how do I release the stored energy in a cap? What kind of capacitor would you recommend and how many? What kind of battery?

 

I've never made anything like this before so tell me how bad the shocks can be too.

[insane_alien]

right, this is a pretty good tutorial http://www.jeffhove.com/robots/coilgunhowto.html

 

i used a similar one a while ago. since you are apparently new to high voltage i'll describe some of the risks.

 

explosions, burns, cardiac arrest and death. lots of nastiness. BUT these only have a chance if you are not careful. if you are careful high voltage is a laugh and you won't get anything more than a mild shock(like touching an electric fence, go touch one so you see what it's like. good for encouraging safety. i tried climbing over one when i didn't know it was electric and, well it wasn't fun).

 

basically, the rules are, treat everything as if it is charged and ready to shock you at any moment.

 

electrical insulation works, rubber soled shoes, rubber gloves, plastic handled screwdrivers, these are very useful.

 

don't lick anything.

 

if firing a projectile, don't aim at face, friends face, cat , whatever.

 

don't try and get THEM to lick anything.

 

don't do it next to a computer or TV. they don't like EM pulses.

[Rocket Man]

if you go small scale, you can get a reliable firing with under 30V

it's the feild strength that's important, get the coils as snug as possible to the projectile and get the current in there suddenly.

nicad rechargable batteries give quite a good pulse, way beyond their ratings.

if you want to do damage to the target, you need some expensive equipment.

[Guest026]

when im done with this single stage can i salvage parts to make a multi stage gun?

[Rocket Man]

you certianly can, although the budget gets pretty big if you go high power.

the simplest coil gun you can make involves buying a roll of wire and connecting it to a high current source with a nail sitting in the back end.

to go multi stage, get more wire and an optical switch.

 

high voltage high current takes transistors that weigh a few kilos and they cost about $100 each.

if you go low power, you can pick up a few cheap power transistors to do the switching, the coils are the same there's just more of them.

[fattyjwoods]

that sounds like fun but what are you going to make it for?

[eggman]

i've made a coilgun for probably no more than $30 and a good deal of time that shoots clean through a soda can at 20' away. i used this tutorial http://www.instructables.com/id/Coilgun-Handgun/ as a guide and it worked very well.

 

the reason i came here is to ask about multi stage guns. ill make another topic though, so as to not hijack this one.

[GruesomeCharnel]

I am trying to build my first coil gun and I have had an idea. Since making a coil switcher is a little beyond me I thought of a way to bi pas it. I would make a copper pipe slightly before the coil and cut the pipe in half and then put them together but slightly apart next i would connect the capacitor to the coil then to the connector (copper pipe) than connect the other wire to the other half of the connector. With this set-up when the projectile touched the pipe it would close the circuit, turn on the coil and then disconnect after leaving the pipe and continuing on. Would this be a possible solution to complicated coil switchers??

[big314mp]

If you could get the gap spacing right, you could use that. You will probably have to slot the copper pipe, otherwise it will do a good job of blocking the magnetic field.

[GruesomeCharnel]

What do you mean "slot" the copper pipe?

[big314mp]

Well, you shouldn't use a metal tube, as the rapidly changing magnetic field will induce eddy currents in the copper pipe. These currents go in a circle around the circumference of the pipe. To stop these currents, you cut a slot in the pipe, thereby breaking the circuit.

 

http://powerlabs.org/coilguns.htm

 

Skip down to the bit about the solenoids.

[YT2095]

switching is easy, use a photo emitter/collector pair between the coils to pick up the projectiles position.

use thyristors to switch the coils.

 

and don`t ask me for any emitter/collector pairs, I gave them all to Gilded a few years ago for his coil gun.

[big314mp]

An interesting one may be using an LM555 timer set in one shot mode to create a pulse of a given duration. Adjust the pulse length using a variable resistor, and you could get a coilgun with a dial in range.