SpudFiles

I have been wanting to make a mini for a while now, at least a cannon that is easy to hold in one hand, but many seem to be hindered by:
a) Being difficult to get a fuel/air ratio correct.
b) Looking very ghetto, such as being taped together, and obviously a pen in a medication container, with a lighter on the side (or something similar).
c) Being awkward in general.
(No offence intended to anyone who is protective of their mini.)

This is why I have decided to go for something a bit different. I have decided to make a mini that uses magnetic fields to propel a bb rather than combustion or pneumatic, commomly known as a Coil Gun.

I have been unable to find any topics on this subject, and since I do not have enough smartness to understand some of the explainations on other sites, I was wondering if anyone has done this before or had any experience with this and can help me out. If i have missed a thread, please just point me in the right directon.

go to http://www.anothercoilgunsite.com/nf-po ... uction.htm

that guy made some hand guns that fire metal slugs

it would take lots of tuning to ge right, but would be very cool.

here is an idea for a VERY simple one. (no, i have never built one and i am in no way a profesional)



take a peice of pvc (maybe 1/2'') and make a giant electro magnet about 1/2 way up the outside of the pipe and use that to shoot the medal darts. it would be cheap and it might work.

i like the idea though.

Yeah, I might do that for another, larger, more rifle-like one, but the one I'm planning to make will be too small for darts, and probably have a straw-sized barrel. Good ideah though, thanks for your input.

The capacitors needed for a rail gun are huge. If you use more than one capacitor and acceleration point everything become much much harder. It's a challenge if you're up to it.

i was looking around and this is accually very interesting, yet so simple.

some people made them using a camera flash curcuit, i was thinking maybe a stun gun would make it work well. would that work?


im just throwing out ideas.....

if you build a multi coil gun then you will need a timing system( a PIC or something) to make sure that the magnets are not left on too long and pull the slug backwards!

It is a lot more trouble than it is worth, I built a small one and it was rather unimpressive for the work that went into it.

TechnoMancer wrote:if you build a multi coil gun then you will need a timing system( a PIC or something) to make sure that the magnets are not left on too long and pull the slug backwards!

that is why i suggested using only one coil, though that would be even more unimpressive.

I used to be into making them, I did a few experiments but never really put the money in to build a proper one.

There are a lot of things that can affect the performance of the gun, even a simple single coil gun needs to be timed correctly so that when the projectile is accelerated, the magnetic field is broken so it doesn't pull back the projectile. This can be done by either using some kind of sensor and timing circuit or decreasing the time taken for all the energy to be discharged.

That is why some people can make the most basic guns and some work really well and others don't, even though they all have the same basic components.

If you can make a good one it would be sweet as.

If you want to build a coilgun, don't build it as a mini. It's very complex, and the gain is proportionately small. After you add the capacitor bank, it won't be a mini anymore!

i dont think a stungun will work because you need amps and not volts.

I built a small one out of a some plastic tube, some copper coils and a camera flash. Was easy to make and shot a nail across the room, but it wasn't that great. if you are good you can make a good one.

Pilgrimman wrote:If you want to build a coilgun, don't build it as a mini. It's very complex, and the gain is proportionately small. After you add the capacitor bank, it won't be a mini anymore!

In their most basic form, these are relatively smal and only need one capacitor, or a bank of small ones.

But i'l probably get stuck into this next weekend, because I'll be using this whole week for a 4000 word report for school: on combustion vs pneumatic spudcannons

i built one for the science fare last year shot assorted 1/4 metal slugs roughly 15ft at a 10 degree angle. it used a series of complicated homemade (and very fast charging) charging circuits at first but they kept on blowing my psu's so i eventually decided to use a camera flash. the capacitor bank contained two 1000uf 350v capacitors which took about 1minute to charge with the camera flash. i sharpened one of the projectiles and got it to shoot clear through a soda can. anyway if you plan on using like one camera flash/capacitor you might be able to shoot a metal bb or part of a nail 30ft at low velocity and a 45 degree angle of fire. i have made a few before but none of them were impressive enough to me to actually put ton this site. i think this winter im going to buy some Pic micro controller and build a decent multi stage gun.

through my experiments.... to get the best performance out of a coil gun you want maximum current. meaning low resistance wire (one of the most important parts) and a high voltage source (remember current is proportional to voltage... as a basic rule the more voltage you put in the more current you get out). if possible charge the capacitors in parallel and discharge them in series to get best result.