Picture of How to make a Homemade Railgun
These are brief instructions on how to make a homemade railgun.
In order to make this project, it is necessary to work with high voltages, so don't even think about making a project like this unless you are familiar with electricity, especially capacitors.(ie. Don't blame me if you hurt yourself)

If you ask a question I'll try and answer it.

I made this for my science fair project in order to see how efficient I could make a railgun (not very). See this here:

If you want to see video of this its on youtube:
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Step 1: Making the actual railgun

Picture of Making the actual railgun
Ok, so this involves actually making the railgun. So, my one essentially consists of rails sandwiched between two sheets of perpex. The first photo shows this. You can see on the sides two extra sheets of perpex next to the aluminium rails. This was initially meant to make the railgun stronger, but in hindsight was unnecessary. 

I used 6x20mm aluminium, and 6mm perspex.

This top down photo shows the "fake" perspex rails on the right, and the aluminium rails on the left. If you don't get how this works, i'll explain it at the end.
The transition from the perspex rails to the aluminium rails needs to be smooth so sand it lightly.

There really needs to be a close tolerance of the projectile fitting inside the barrel. I had a bore of 6mm, which made it easy to use the 6mm aluminium as a spacer to make sure the gap was 6mm all the way down.

Step 2: Attaching the Cables

Picture of Attaching the Cables
This is not the ideal way to attach the wires, as not the greatest surface area, but it is the easiest.

I used 25mm copper wire and some lugs.

Step 3: Injection System-1

Picture of Injection System-1
I used some hose to connect my air injection system to the railgun, just to give myself some distance from it. I simply glued the hose to a piece of wood which is screwed on.

The mesh is there to stop the projectile falling into the hose.

Would extending the length of the rails be any benefit? or do the capacitors have enough time to fully discharge at this length?

gathem1 year ago
This is a great instructable. There are lots of railgun tutorials, but you answered some of the questions I had. Everything was very clearly explained.
gathem gathem1 year ago
How does it work? Does it accelerate faster than on air pressure alone?
marcrigter (author)  gathem1 year ago
Thanks! It works because of the Lorentz force- current in a magnetic field experiences a force. My experiment was to find if there was any acceleration. Although it managed to accelerate some sparks quite quickly, it did not accelerate my aluminium projectile at all. I think this is simply because I didn't generate a large enough current. I made a video about my experiment which is on youtube by the way :)

Awesome !!!

The one I built years ago was strickly electronic !!!

But this idea of using air is definatly a good idea also !!!

Especialy if you set it up to use Paintball Gun Tanks !!!!

Thanks 4 Sharing Again !!!

25 years ago, I made a Rail Gun out of PVC PIPE that was barrel I held all my sections of bolts (Electro Magnets with relays)!!!

I got so hyped knowing that they were making Guns Now,

but upset also because I should have patented my idea but I imagine someone else was or had already made one too, 25 years ago..

I could send steal projectiles through concrete blocks no problem !!!

I never got to do more than a couple weeks of testing after my Mother found out..

She got rid of it on me while I was at school because she felt it was too dangerous..:(

But now I am collecting all my materials again at age 37, to make a really good one !!!

I got plan's from a guy that built a "Sentry Gun" Which I am in the middle of building also !!!

Hey maybe I will be able to combine my Railgun on to a Sentry Gun Platform !!!

The hardest thing would be to design a perfect ammunition & way to load automatically & eventually rapidly if I can get the gun to be efficient enough to take quicker shots !!!

Well Thanks for sharing !!!

You can e-mail me at :,

If you would like to talk more !!!

Thanks Again !!


djsponge9 months ago

Where did you buy your capacitors?

marcrigter (author)  djsponge8 months ago

Alibaba :)