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DIY Coilgun very pretty, not so deadly Answered

Want to scare someone with a pretty frightening looking gun? This DIY coilgun will get that job done. With the projectiles going out at only 100 fps this is far from a deadly weapon, but just look at it! The $130 pricetag is almost enough for the looks alone.

Full specs below.

Fully semi-automatic, up to 14 shots.
Capable of delivering over 18J kinetic energy, and speeds up to 110km/h! (42 gram projectiles).
It's a single stage gun, using a 8800uF capacitor bank with max 400v (704J).
Max shot efficiency is 2.8% but reaches almost 4% at lower voltages.

Charge time for 300v (12J kinetic energy 396J capacitor bank) is 8 seconds for the mains connection, and when using the internal batteries about 90 seconds. It also has a Digital voltage display.

Coil overheat after 14 shots at 300v.
Total weight: 5 kilogram.
Total spend: ~ 100 Euro
Construction time: ~40 Hrs

DIY Coilgun via engadget



5 years ago

I personally think the light bulb is ugly, I would just use an led, but then again that would require complex wiring and stuff.

whats the light bulb for

according to the site, it is the charge capacitor

*Charge Resistor* PS just seen the comment's date. oh well, better late then never.

the light bulb is to indicate that the caps are fully charged
it goes off when they are charged

Probably when it shoots, it light up... I'm guessing it's mostly for the looks

the light bulb i would guess is for safely discharging the capacitors when your donr destroying household objects, and or dumping the back emf from the coil after firing.

Have you atleast tried to shoot at a human being before telling people it's totally safe? A gun with the power of 18 Joules would atleast penetrate the skin, so don't mislead all those people that have been watching this.

if the bullet was smaller, it could probably penetrate easily.
I gave a coilgun with only 8 photoflash caps, and the bullet can go at 140 fps

100 fps is still not very fast. Yes, it can put an eye out, but you can do that with a metal bb as well.

But, a metal bb weighs very little, while these metal slugs weigh 42 grams, thats over an ounce.

True, it will probably do more damage than a bb, but it's sill far from a bullet. Either way, I never said it would feel like a unicorn tickling you with a feather, just not deadly.

True, but I never said that these will do the damage of a bullet, just more than a bb.


Are there laws in place for these type of weapons. Are they prohibited?

I've been wondering the same thing for quite a while. If not, I hope it doesn't happen for quite some time, I want to make a coilgun too :D

Heck, now I want to make a coilgun. My goal: make it out of scraps from the house, spending as little as possible.

Alex the great made one (so did I). We got the cameras from CVS and paid a dime for each.

I've changed to something equally as dangerous that doesn't use ammo... A laser gun made with a DVD burner laser diode, a standard red laser pointer (who is going to use gun-sights to aim their high-tech laser gun!?), 2 AAA rechargable NiMH batteries, and 4 LED's. Not to mention 4 pushbuttons and a switch.

dvd burner lasers arent equally dangerous, theyre only about 200mW. it would damage your eyes and maybe sting your skin, but thats just about it. the coilgun is more dangerous because it uses high voltage, and the projectile has enough force to hurt pretty bad and do some damage

They are equally dangerous when you put 7 of them in one space. Anyway, this was ages ago, and I did scrap the project after completion on the grounds that I could make something better.

o sry. I thought you were just using ONE laser. seven is pretty powerful

When I design something to be dangerous, I go for overkill. I could start 2x4's on fire, cut plastic, or leave a really nasty burn. Granted, some of that took time to do, as, let's face it, I'm doing destruction with light. If I ever went to rebuild it, I'd be in the market for 16 laser diodes...

You may violate one or two parts of a firearms code depending on where you live but you probably won't get in trouble. By the time you can get lethal energy or velocity from a coilgun you could have killed somebody long ago with a discharge from the capacitor bank. Very nice looking though!

the firearms codes do not apply to a coil gun, for there is no explosive force to propel the projectile, meaning that this is simply not a firearms, but there may be exceptions made if you use it against others.

in the uk any pistol generating more than 8.1j of kinetic energy or any rifle generating more than 16.2j of kinetic energy is considered a firearm and requires a license

Shat nice design andloads of power it looks

OK. The flashy designed is useless in any situation. The one me and my friends made a while ago was a PCV pipe with a 30m x 2mm cable attached to a trigger/switch and a power supply. It couldn't take to much power either. the longer and thicker the cable is the more power it can take and the higher the magnetic force it out puts as well.


9 years ago

Beautiful, but useless.

If the projectile doesn't do enough damage to someone, I wanna unscrew the light bulb and jam it in their face a few times. Actually it makes a great current limiting device, but it looks pretty fragile and exposed where it is now.

We need some instructables for coilgun's without using camera flash units. my mistake if there already is one, actually, if anyone knows of one can they post up plz. :)

Why without camera flash circuits? They are easy to get and can provide enough voltage to charge quite high powered capacitors. They can be extremely elaborate consisting over many stages. I hope to make an instructable for a signle stage camera circuit gun I am building now

yesssssss. but it just doesn't feel like you've made it yourself if it's part of something else. But if you like to do it that way, then thats fine as well. I was just wondering. But dwdw, i'v got it sorted now :)

What is the point of the light bulb ????

It is used as a charging resistor. It will let you know when the caps are charged

. It does look awesome, but what is that lamp above the muzzle and laser pointer for?


From the comments on the link:

The bulb is used as charging resistor for the capacitor bank when using the mains connection. the higher wattage, the faster it charges. the problem with charging resistors is that they will dissipate a lot of energy, at this way it is safely dissipated which means less heat inside the gun.

100fps might not be spectacular, but 42 grams at 100fps is gonna leave a mark...

. Thanks. I scanned the article, but, obviously, missed that part. . Once someone has been hit a time or two, the sight of the light coming on should strike fear in their heart. :)

Agreed. That just looks like something I'd build for defense against annoying salesmen.

There's actually a bit more to it than the (maker's) note mentions--the resistance of a tungsten filament increases when it's hot (something like 15 times at full temp.) So a "lightbulb resistor" is an automatic current limiter. Too much current, the filament heats up and the increased resistance drops the current draw...

that is so totally awe some

Deadly? Probably not. Uncomfortable, yes. Lay on your back, lift a 5lb lead diving weight straight over your face and let go, that will be about 18 joules smacking you in the schnoz.

Turn it over and it looks like it can make french fries or popcorn and keep them warm with the heat lamp.

love it, thats amazing for only fourty hours.. I usually take much longer for anything..


9 years ago

I think they spent too much time on the case and not enough time on the innards. Very cool though!

Eeeeeh! "Set coil-guns to awesome" is a world away from "set phasers to stun"... L

The lightbulb ruins it :( Pretty cool either way. If I had time to blow, and electronic know how, I'd be making these.