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MR-1.2 Coilgun (UPDATE: NEW INTERIOR PICTURE)

last photo ←

A coilgun that I built. It started as a prototype and I decided to put it in a gun body. I then continued to make improvements from the MR-1 to the current version the MR-1.2. I have not done the math but I intend to do some tests and figure it out soon. Please pardon the rough appearance since this was only a temporary design to house the components.

The MR-1.2 features a two sectioned capacitor bank, new safety insulation, a relay, a safety charging switch, a four layer coil, 3x AA power source (parallel), extra ammo tubes, and a laser sight (actually sighted in).
Gun fires with surprising power. ( If you really want to know ill give you the specs to beat me to the calculations)

I will continue to work and build new guns (much better looking too)
any questions feel free to contact me .

Instructable / video to follow if requested

Charge time: approx 30 sec with 3xAA (longer with less)
Cap bank specs : 14 X 100 uf 330v caps (average of 80-120uf caps)
Coil approx 40mm x 4 layers (inner diameter is bic pen tube)
Relay runs off nine volt with push-button switch
Charging circuit modified to auto-charge
Rounds= 2-3 cm nails/screws (experiments used 6mm airsoft bbs to adjust round placement)

Disclaimer: I accept no responsibility at all for what you may do with this information or any damages/injury/death that may occur.This project uses DEADLY electricity as well as high speed projectiles. Do not under any circumstances try this unless you are trained with high voltage electronics. BE SAFE!

Please note before even considering a similar project: These are very dangerous, not even considering the projectile danger, the electricity is enough to kill you many times over. I use many precautions while working and I have the experience necessary to keep me safe. I do not allow anyone else to use the gun dangerously or open it up. Just in case, I encourage the use of a rubber glove when others are using this just in case (I don't want others to be harmed by my work ever and I alone have the responsibility to decide my own safety and use at my own risk). As for the projectiles, I treat this as a real gun and use full gun range safety procedures. Projectiles will hurt and could be very dangerous. Finally, please don't let this disclaimer get you down, just be safe and have fun!

cheers and please rate and comment!
Mspark400

36 comments

May 18, 2009. 5:48 PMLandon Sullivan says:

I don't know what a coil gun is, but if it is anything like a rail gun, I then I know what it is. A video would be good, but only if it is in Google Video. My computer doesn't agree with the Youtube video player.

May 18, 2009. 6:12 PMmspark400 (author) says:

To be technical, a rail gun and a coil gun are different. They both use bursts of of high voltage electricity, but the means of propusion is different. A railgun uses an expanding arc of plasma to propel a metal slug using the gases produced when the arc travels through the rails/slug. Using a similar electronic capacitor setup, a coil gun lets that burst of electricity run though a thick coil creating a very strong electromagnetic field to put it simply. this field attracts the metal slug (sucks it in so to speak) and then, if timed properly, shuts off when the slug reaches the maximum magnetic field in the coil. the slug then continues with the kinetic force that has been induced into it. I know its complicated but I hope this clears it up. If I do post a video I will post in both formats. cheers, Mspark400

Oct 1, 2009. 5:18 PMCeiling cat says:

Actually I think a railgun produces an electro-magnetic field. I forget what it's called. The (someones name) effect.

Jan 23, 2011. 3:29 PMleodahsan says:

lorentz forces effect.

May 23, 2009. 6:53 AMLandon Sullivan says:

Thanks.

Jan 17, 2011. 5:00 PMcardboarddude says:

which is more important in determining the energy produced by the coil gun, the number of microfarads a capacitor has or the number of volts a capacitor can hold?

Jan 21, 2011. 11:25 AMleodahsan says:

volts, as the joule formula is V² . C / 2.000.000, where V is capacitor voltage and C is capacitance in uF.

Nov 2, 2009. 7:06 AMbryanb333 says:

lolz i managed to get mine to fire once with an input of ~9vdc off a reg power supply then it died but dang it shot good one question tho did you put ur caps in series of parralel... ive done both and dont seem to get much of a difference. and a side note you can safely run the circuit at 3vdc w/o much harm to the transistor if you feal compelled you can aways attach a heat sink to the transistor which will help its lifespan. but any ways i like the idea of parralle battteries.

May 20, 2010. 11:34 AMybahman says:

If you put caps in series, the capacitance is lowered. If you put them in parallel the capacitances are linearly added.

Jul 16, 2009. 4:25 PMeneergcam says:

yours looks like it would fall apart any second. you should have had a bigger container.

Jul 19, 2009. 6:18 PMmspark400 (author) says:

to be honest the thing is dead solid. cheers, mspark400

Jan 10, 2010. 8:17 PMcdousley says:

i say put some hot glue/5minute epoxy on that tape and give it a gool paint job nice coilgun

Jan 10, 2010. 1:05 PMmax0506 says:

Hello guys
I am making a coilgun made of a disposable camera and some capacitors.
I have made a drawing with google sketch-up. Could you please check if I have made all the connections right? ( I am not an expert ……… yet)

www.elektronica_stuff.webklik.nl/page/voorpagina

Jan 10, 2010. 2:57 PMmspark400 (author) says:

Hello and thanks for your interest,
Unfortunately I am unable to really see your connections with the link provided. Also, the charging circuit puts more than 400-1200 volts (depending on input voltage.) Your caps have a low voltage rating. Charging such caps comes with extra concern. I would suggest photo flash capacitors from the cameras or an online source. However, several other instructables go into greater detail about these circuits so all problems should be relatively easy to clear up. If you have more questions feel free to ask.,
cheers,
Mspark400

Jan 6, 2010. 9:13 AMmax0506 says:

(removed by author or community request)

Dec 21, 2009. 12:31 PM~ZOMG says:

I came.

Seriously dude, this is amazingly awesome.

Now you need to get one of those laser tag rifles and make another, more powerful coil-gun.

May 21, 2009. 3:49 PMjohn333messick says:

i like this device, do u have a PFD for it.

May 23, 2009. 10:53 PMmspark400 (author) says:

pfd? surely you dont mean a personal flotation device? cheers, mspark400

Oct 1, 2009. 5:15 PMCeiling cat says:

I believe he means PDF. The printable, book-like format of 'ible.

Jun 11, 2009. 9:02 AMalvin9861 says:

I have used an auto car coil for for power for my coil gun. It gives me all the power I need.

Jun 1, 2009. 8:38 PMBaddul3 says:

Do u think the circuit board will be able to handle 25 330v capactiors (8250v) and if so how much punch do you reckon the projectile will have?

Jun 2, 2009. 1:27 PMmspark400 (author) says:

theoretically yes it could. the only disadvantage would be charge time and i believe there is more stress on the board.putting several boards in parallel can increase longevity as mentioned in other coilgun 'ibles. as for punch i cant say without the uf rating on your caps (thats whats important) even so i could ball park the effects but there are also calculations you can use to find joules etc and guess at efficiency (4% is impressive lol) cheers, mspark400

Jun 1, 2009. 7:54 PMBaddul3 says:

Ok so ur batteries are in parallel right? Because i've built two coil guns of my own and cannot charge the capacitors with more than 1.5 volts as it burns out the board and/or the transformer. Also what advantage does the relay give? None of mine have one.

Jun 1, 2009. 8:06 PMmspark400 (author) says:

yes the batteries are in parallel. it is still1.5 v but there is more available amperage. the relay is a able to switch higher amounts of current. most switches are not meant for this type of power burst and many (and i have tried) have either welded together or just generally failed. theoretically it also could switch faster than a normal switch. cheers, mspark400

Jun 1, 2009. 8:17 PMBaddul3 says:

Ok thanx

May 27, 2009. 9:46 AMinductor says:

Cool this thing is really able to charge a 1440µf capacitorbank in 30 seconds with only 3 additional batteries? Usually disposable camera chargers don't like additional batteries. A video would be awesome, too.

May 27, 2009. 1:03 PMmspark400 (author) says:

yep, technically it charges most of the way in thirty seconds but can take up to two minutes to illuminate the indicator led and reach a completely full charge. this depends largely on the batteries. Ill try to get a video soon.
cheers,
mspark400

May 28, 2009. 9:53 AMinductor says:

So it's all about the batteries.
http://www.coilgun.info/mark2/rlcsim.htm
This toll helps creating a coil that matches the cpacitorbank and the projectile.

May 18, 2009. 7:58 PMmarcos101 says:

o.o;; uhhh... holy crap that was very scientific. you must have done allot of research about this stuff

May 19, 2009. 12:45 PMmspark400 (author) says:

lol thanks, not specifically but I have done more than a few high voltage projects as a hobby and it definitely makes it safer to know what you are up against hope you enjoy! cheers, Mspark400

May 26, 2009. 4:29 PMmarcos101 says:

I'm new to the whole Instructables and making stuff. but I'm starting to want to make things so I want to learn about stuff people have already done so I think this is an extreamly cool thing you made and when I get better at making things I want try to make my own. ^_

May 26, 2009. 6:50 PMmspark400 (author) says:

Well in that case ...Welcome!(and thank you) If you would like any information on my projects (or just general questions) feel free to pm me or whatever mode of communication is best for you. cheers, mspark400

May 26, 2009. 8:15 PMmarcos101 says:

thank you. :) do you know where to find info on how to do basic electronic stuff?

May 27, 2009. 1:05 PMmspark400 (author) says:

Its not much of an answer but google is your best friend. If you search the right things, it will lead you far past this project. Of course Instructables is my main source of inspiration and had quite a few great tutorials on basic electronics. cheers, mspark400

May 27, 2009. 6:01 PMmarcos101 says:

thank you. :D