Disposable camera coilgun

A tutorial explaining how to build your own coilgun from some disposable camera's flash circuits.

It doesn't require much money (if any), but you need some basic soldering skills and electronics knowledge to finish it successfully...

If you have any questions don't hesitate to ask me!

Step 1 Getting the parts

What do you need

- About 5 disposable cameras (used) with flash circuit (you can probably get them for free at your local photo-store if you ask nice)

- A soldering iron

- Some wire

- A plastic ballpoint-pen, ink tube removed so you only keep the hard outer plastic tube

- A light-switch

- Electrical insulation tape

- Plenty of enameled magnet wire (ca. 0,5mm diameter)

- Some soldering skills and some electronic knowledge

Comments

[alvin9861]

I'm using an old paintball gun for kicking the round stock to the coil. I took out the guns barrel and made a new barrel with my coil on it . I use an auto ignition coil for my power source w/out caps. It does very well w/out the caps and can fire rapidly w/out constant charging.

[positr_n]

what do you use to power the ignition coil?

[jbussé]

+32 number that ought to be BELGIUM !! hallo mede bewoner van het regeringsloze land :D

[AlfonsVH]

Aangename kennismaking lotgenoot!

[diy_bloke]

Hoe lang nog, gewaardeerde zuiderburen?

[AlfonsVH]

Ik heb er geen idee meer van...

[diy_bloke]

Di Rupo ook niet meer :-)

[Electronics Man]

Do the capacitors have to have the same rating if I wire them in parallel? I have 2 80uf, and 4 160uf but they have different voltage ratings. Can I use all of them together?

[LeelaKrishna]

yes

[Articas]

do i have to leave the flash bulb in the camera circut

[LeelaKrishna]

no you have to take it out

[R.A.T.M]

how do i know wich way it fires

[firefletcher]

Aim it at your face and fire it. You'll soon find out.

[cherwa]

do you have to put the capacitors in order from biggest to smallest? or can they be the same size?

[penguin27388]

no, it dosn't matter in parralell the capaciter volts/uf are added together

[vbexpressrocker]

No, in parallel the capacitance of the capacitors are added, not the voltage.
In series, the capacitors voltages are added together, and the capacitance is taken away from each other.

[leven]

If you need to ask that, you should not try this.. the 300 volts cap would have no trouble killing you.. so read up a bit on basic electronics and you will now the answer, and how not to kill yourself.

[LeelaKrishna]

I tazed my self atleast 300 times with just one capacitor of 330v and hey i'm still here It just hurts like hell for about 2 mins

[badideasrus]

i care to disagree. 300 volts means crap if the amperage is super low.... like a flash camera's cap is. besides, volts don't kill, amps do.

[usb key]

A diagram would have been nice

[R.A.T.M]

pleas help if i have the coil coring the hole pen but 1 1/2 inch n the front

[fsilva-1]

The battery is not charging the circuit. I have tried everything but it is useless.

[padmanabhapsimha]

why don't you build a boost converter? it is more efficient than a camera charging circuit. It just requires some basic knowledge of electronics. really effective too. it charged my12000 MFD capacitor to 63 volts in just 20 seconds. yeah it is 12000 micro farads. works better than a 120 to 480 micro farad cap (single 120 or 4*120 in parallel) charged to 400 volts. you can also build a simple power cutoff system so that you need not disconnect the battery from the circuit. you can control this entire system using just two 555 timers. One for the charger and one for the trigger. it will be better if you replace the relay with a solid state switch like an SCR, triac or a thyristor. mine is capable of switching 800 volts , 260 amps of current. There is also no danger of any welding of contacts. It also reduces the power loss by 30 to 40 percent

[xmitman]

Hi padmanabhapsimha,

What SCR part number did you use?

[padmanabhapsimha]

my prototype used a TYN616

[padmanabhapsimha]

i used a 'NTE5519' . You can use any SCR or triac with a surge current rating of 600 amps. you can usually overshoot this rating if your cap discharge time is lower than 16 milliseconds

[bendog38]

 would a .177 caliber pointed airgun pellet work as ammunition

 what about a small plastic airsoft bb           and what is the fps on this thing

[badideasrus]

it would work in a rail gun (the lead pellet), however. but as they said, it has to be magnetizable (for those who don't understand 'ferromagnetic')

[bendog38]

then how do I make a rail gun? seriously, i want to know, i have a science fair at my high school coming soon.

[padmanabhapsimha]

i would advise you not to build a railgun with just basic components for a science fair competition. a coil gun will produce more impressive results and it won't be damaged by wear and tear if you construct it properly

[badideasrus]

sorry for the late reply. a rail gun, in it's most basic form, is just two rails that you pass lots of current through. i made one once from tin foil and a nail. it was a really childish effort, but the nine volt battery was enough to burn holes in the foil, which was neat.

there are several sources for rail guns on the net, do some searching. and above all, be carefull. the bigger the gun you intend to make, the more likely you'll kill your self with electricity.

[bombmaker2]

Neither would work because plastic is nonferrous and airgun pellets are made out of lead, which is also nonferrous. As for fps, I don't have a clue. 

[badideasrus]

fps would really matter on how much juice your giving it, right? so theortically, no two shots would ever be the same without some kind of capacitor measuring thingy.......

[bombmaker2]

Pretty much. But I'm not sure how much of a difference there would be.

[M4A1DrumRoll]

it has to be metal

[Shambler]

If it's a plastic pellet, unlikely. Coilguns shoot projectiles with a sudden pulse of electromagnetism, ergo any projectile must be ferromagnetic i.e. made of iron or another material attracted to a magnet.

[Ma77h3w]

I created one using just the circuit from 1 disposable camera.. and used a push switch to activate it. This welded shut and was rated at 250V ac at 5A I've got a relay to do it now rated at 28V dc / 277V ac at 12A. Will this work? What sort of current goes through a coil like that? My coil has almost no resistance

[padmanabhapsimha]

you do not need 28 v dc to activate the relay. usually relays need 9 to 12 volts to activate them. your relay's ratings is the maximum voltage and current it can switch.

[zack247]

you will need close to 28v to activate it, try finding a car relay at your auto wreckers, they can be activated by 9v and are simple to use.
one is used in this instructable: http://www.instructables.com/id/Coilgun-Handgun/

loko at picture 2 of step 4 to see how it is wired up. on the bottom of some relays there are markings, the two pins marked with a swirly sort of line is where you put the 9v, and NO and COM are your "switch" leads

[zack247]

COM can also be labeled as just C, too.