The making of a powerful low cost coilgun which is portable

Picture of The making of a powerful low cost coilgun which is portable
In this intructable i will show you how i made my coilgun, I will first thank, steaveastrouk, re-design, lemonie, orksecurity and others who helped me with my questions.  I became quite interested with this coilguns from the videos that was featured on hacked gadgets and intructable. So i decided to make my own research to understand how it works. After months of research i decided to go to the practice session.

 Comment PLEASE
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Step 1: Parts list

Picture of Parts list
Well for the design use you imagination because the parts that i used for the casing will be very difficult to find because they are all from a dismantled photocopier. Therefore for the electronics you will need some parts that is easily available on market or by salvaging them


  400V Electrolytic Capacitors. The more capacitance the better it will be. say like over 2000uf or more (Free)
 1k 10W resistors X 2(Rs20)
 BD243C or 2N6121 transistor or equivalent X2(Rs64)
 A centre tapped transformer on primary. we will come to that later on(free)
 A power supply that is rectified mains, car battery, or other batteries, in my case i used 10 AA 1.2V NI-CD batteries (12v in series)  (free)
 Some very very high current switches or relays(free)
 Full Bridge Rectifier 400V 3A or more to be on the safe side X 2 (free, salvaged from TVs)
 A 100W bulb(Rs21)
 Lots of wires(Free)
 Aluminium Tubing(R75)
 Enamel coated wire, i used the 1.2mm wire that i got from a tv.(free),, u can also use bigger wire for more current
2 Medium Heat sinks

Step 2: Tools And other materials you will need

Picture of Tools And other materials you will need
Hot melt glue gun
Soldering iron
Wire cutter and wire stripper
Pencil for marking...............
Drilling machine

 Useful goodies
Metal sheefs and a food container(plastic) of appropriate size for the casing and  insulation
Duct tape or electrical tape
Solder the 2mm one
Flux (optional if your solder is not of too good quality)
Card Board
Battery holder

  Probably most important is a place to work. i conquered my mother's kitchen a few years ago and made it my workshop
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babutxt3 months ago

Can this coilgun will be able to fire a 50gram projectile

" A centre tapped transformer on primary. we will come to that later on(free)"
what does it mean?
explain about it to me please
ARJOON (author)  Nuclear Radiator6 months ago

found in old phone chargers. where the secondary is centre tapped. Here we use the secondary as the primary since we need to get from low voltage to high voltage.

sorry for late reply


Will you please tell me that if there is any part which can replace CD battery or where to get CD battery.
ARJOON (author)  Nuclear Radiator2 years ago
it's a Ni-Cd battery (Nickel–cadmium battery). i used 10 in series 1.2V each resulting in 12V.

any other 12v power source is OK,

you can even use a computer powersupply if you want to sacrifice mobility
or use 2 6V SLA batteries/
you have the choice
then what should be amp of it?
ARJOON (author)  Nuclear Radiator1 year ago
and yes are u teeling that all that circuit near the coil can be replaced with a high voltage momentary switch??
ARJOON (author)  Nuclear Radiator1 year ago
high voltage and high current
and yes can you show to how to make the coil and attaching it to the barrel?
i know how to make fully automatic design. but still this is a HYPOTHETICAL design.i dunno if this works. if u want to know arjoon then mail me at:
ARJOON (author)  Nuclear Radiator1 year ago
yes it works, i've made it and tested it
can you show me the design?
makdef1 year ago
I got impressed. not so elegant. but very clever this project. I am with a project like this. but Smaller. and I don't know, but the following tip maybe would help you: you can use more of one charger circuit. In my case, I'm using joulethief with secondary coil. so for me its's easier to have more of one circuit charger. and you must to use diode on the outs of each circuit to do not cause problems. and after the diode you can join them according with the polarity.
ARJOON (author)  makdef1 year ago
joule thief would take an eternity to charge the bank.
Can you please tell me that how to make the coil and attach it to the circuit?
It would be a big help.
shock5171 year ago
how are the batterys 220V in. or where is the power coming form you didnt explain how to connect the batteries to get that 220v?
ARJOON (author)  shock5171 year ago
don't get confused, this is a hybrid charger, using both batteries and mains current, the 12V in comes from the battery, and the 220V from the mains which is rectified to charge the capacitor bank.The inverter will achieve your desired voltage depending on the input voltage and the trasformer ration
scci2 years ago
How fast cand far can it shoot?
ARJOON (author)  scci2 years ago
hnnnm the measured speed depends on the mass and length of the projectile,

using sensors it is estimated to shoot about 150-250m/s on a full charge

and the effective range i don't know
nice work !
leekg2 years ago
instead of using aluminium tubing, can I use like a plastic tubing?
ARJOON (author)  leekg2 years ago
yeah it's a must, i didn't make the coil around the aluminum tubing, all my coils are coiled around plastic tubing
(removed by author or community request)
ARJOON (author)  thetkdchamp013 years ago
use the schematic. and the AC in is optional.and complete schematic is available on step 7
jpillai3 years ago
so basically it is an inverter with a stepup transformer and rectifier bridge try using voltage multiplier i endded up getting two blown caps hee and last step you told about using thick wire for low volt and thin for high isnt it wrong? it should be just the opposite in my opinion
ARJOON (author)  jpillai3 years ago
i don't thinks so. cross sectional area of a wire is inversely propotional to resistance. Therefore if you use thin wires the resistance will limit the power, so you will need a high voltage to carrry mo current. V=IR, P=IV

Xsectional area= (resistivity)(length)/resistance
lstaničić3 years ago
bad luck... i scavenged a perfect transformer and it has only four pins :/
does the transformer you have used have two coils on the one side and one on the other?
something like this?
ARJOON (author)  lstaničić3 years ago
use wind a very small toroid with 50turns on the secondary and 25+25 turns on the primary. connect the secondary of the toroid to the scavenged transformer. and use the centre tap as the primary of the whole thing
lstaničić3 years ago
why have you added a light bulb? isn't it much easier to add a resistor?
and if i use a 4:2 transformer instead of 4:3 will i need to change some of the other components as well?
sorry for all the questions. i know some basic electronics but i still don't quite understand this... finding a electronics shop that have 4:3 transformers in my country is like winning a lottery.
ARJOON (author)  lstaničić3 years ago
i used a bulb because it can withstand a lot of amps. i need a non-ohmic filament. it also indicates that the cap bank is fully charged when it dims out. Scavenge the transformer from old battery chargers, phone chargers, etc. or wind one yourself. no need to change other components.
lstaničić3 years ago
i have a few questions!
can i charge the bank with 3 or 4 AA's, or does it have to be 12v?
is this a 4:3 transformer?
ARJOON (author)  lstaničić3 years ago
yes, but transformer should be of higher voltage
you have made a mistake in page 2
If you have 200v ones. connect them in parallel to give 400v and then in parallel to increase capacitance.
you actually need to connect 2 of 200v caps in order to double the voltage it can tolerate.
if you use different caps with different uF ratings they will act as a single capacitor with the total capacitance equal to the sum of the individual capacitances they will discharge as a single unit provided you charge them all to the same voltage. what you told about the backfiring and the really slow shot is totally wrong.
ARJOON (author)  padmanabhapsimha3 years ago
i can't formulate english phrases so well. go to wikipedia it will clear your mind
what do you mean? well if you are referring to the non uniform discharge it is wrong. the discharge is uniform. i am telling this because i have built a multistage coil gun with capacitors which have totally different capacitance values. (difference is about 2000 uF) the discharge curve over time is fine as long as the coil resistance and inductance are in the appropriate amount.
ARJOON (author)  padmanabhapsimha3 years ago
you are right
sorry in line two of my comment it is not in parallel to get 400 v but in series.
jensenr303 years ago
Copiers and printers are the best for thin wires!!!
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