Weapons Hacks

279 Articles

Building An Airsoft Claymore Mine

September 1, 2026 by 28 Comments

The Claymore mine is a rather fearsome weapon of war, using explosives to blast a cone of shrapnel towards advancing enemies. It’s not really something you should try and build at home. An airsoft version, though, is altogether more appropriate. [RegiBlackwood] has developed a simple way to build exactly that.

It’s a cheap and cheerful build, with the claymore housing itself built out of cardboard. Wooden dowels are used to stake it into the ground, just like the real thing. In the center of the housing sits a regular old mouse trap. Only, it’s been modified to hold a sling carrying a payload of BBs. The trap is also tweaked to make its spring more powerful, and to enable it to be triggered with the tug of a tripwire. When triggered, the mousetrap fires and hurls the sling forth, spewing a rain of BBs from the front of the device—ideally quelling the advance on your position.

Built properly, it’s a fun piece of airsoft hardware that could really change the dynamics of your regular game. If you’re looking to do point defence, you might also consider building yourself some automated turrets as well…

Creating A Supersonic Trebuchet

August 9, 2026 by 29 Comments

As awesome as trebuchets are, the fact that medieval engineers didn’t create versions capable of launching supersonic projectiles is a bit of a bummer. Fortunately it’s possible to correct this oversight with modern insights and technologies, as [Tom Stanton] demonstrates in a recent video.

While a traditional trebuchet is fairly straightforward, using a heavy weight moving an arm around a pivot that has the projectile attached to the other side, a few tweaks can make it much more lethal. One change is to have the projectile’s rope wound around the arm, forcing an additional pass around the arm to gain velocity. The other is to use a gearing system which uses the dropping weight’s energy more efficiently.

One complication here is that the arm now takes a few rotations to come up to speed, meaning that the release of the payload has to be controlled exactly, with only about an 0.0025 second release window. The solution was both low-tech and effective: since the arm is attached to a drum that the rope is wound onto, the moment enough rope is unwound from the dropping weight, a latch inside the drum is released to launch the projectile.

In a first test with a 10 kg weight, the projectile reached a velocity of around 528 km/h, which definitely was a good start, but also showed just how not aerodynamic the arm was. Some redesigns later of the entire trebuchet, the entire system was tested again with 10 kg and achieved a projectile velocity of 634 km/h. From there it was time to ramp up the weight to the full 40 kg, which theoretically should hit supersonic speeds.

Unfortunately the first attempt hit a mere 1,152 km/h (716 mph), which is just shy of the sound barrier at 1,235 km/h at 39% system efficiency and some components clearly breaking apart. Some more redesigns later and with a lighter projectile at 4 grams, a 40 kg weight achieved an arm speed of 2,342 rpm. The projectile now left the sling with 346.4 m/s, or 1,249 km/h, with an audible snap as the sound barrier got broken.

Even if the era of trebuchets in warfare is well and truly past, they remain fascinating physics demonstrations, with this case in point.

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Building A Fencing Scoring Box

July 25, 2026 by No comments

The sport of fencing requires keeping score, just like so many other similar pastimes. When their club’s existing scoring rig broke, [jc0025] stepped up to build a scoring box of their own, using the typical tools of the maker trade.

The brains of the operation is an Arduino Nano, running the venerable ATmega328P. It’s set up to drive a pair of 8×8 WS2812B addressable LED panels. It’s also hooked up to a pair of fencing socket blocks, which hook up to the lamé (jacket), weapon, and guard of each player for electronically scoring hits. The Arduino is thus programmed to respond to various conditions, lighting the LEDs in turn. For example, the tip of one player’s weapon hitting the other player’s lamé will fire a colored light, allowing the hit to be scored. Meanwhile, a tip hitting the floor will fire a white light, indicating off-target. There’s also a buzzer for sonic indication, as well. Everything is wrapped up in a tidy 3D-printed housing, while power is courtesy of a USB-C charger hooked up to the unit.

If you’re looking to replace some old broken fencing scoring gear on the cheap, this project is probably a good place to start. We’ve featured some other great scoreboard projects over the years, too. Meanwhile, if you’re whipping up your custom own gear for your local sporting club, we might like to hear about it on the tipsline.

The gun on its bipod.

Belt Fed Potato Cannon Spits Spuds

July 6, 2026 by 26 Comments

Spud guns are a staple of summertime fun for the maker set, especially on the Eagleland side of the pond, combining as they do two of our favorite things: firearms and calories. Nine out of ten Canadians agree that there’s nothing quite like a high-speed poutine — but judging by accent [Current Concept] is an American and so his potato cannon needed a little something extra that even the second amendment doesn’t protect: fully automatic firing, with a belt feed.

Like many spud guns, this one is powered by compressed air and uses PVC for both the barrel and air reservoir; unlike most spud guns, it has a steel frame holding it together, and a 3D-printed belt-feed mechanism to bring the spuds into position, with a beefy stepper motor pulling the potatoes. Of course just sticking an extra length of pipe between reservoir and barrel would just result in 80 PSI potato-scented flatulence as the air escaped betwixt the gap, so a pair of piston-actuated, 3D printed fittings slides over the plastic casings in the belt that hold the spuds. It’s not a perfect seal, but video evidence suggests it’s tight enough to get the tubers flying.

Now, there are some caveats — the air reservoir is only good for one shot, so it needs to stay hooked to an air compressor to take advantage of the repeated firings. Since it has to recharge, it’s also only firing a spud every six seconds, so while the mechanism could do “full auto”, it’s actually semiautomatic in practice as nobody’s going to sit and hold the trigger that long. Finally, we must warn you that the YouTuber behind this is trying to be funny for much of the video. Some may find his delivery leaves them in stitches; others will be left cold. There is, of course, no accounting for taste.

Oddly enough, this isn’t the first automatic air gun to grace these pages. It’s also one of the weaker potato propellers, especially compared to this MAPP-gas powered monster. Hopefully [Current Concept] doesn’t see that and get any ideas for the promised revision of his belt-fed tuber tosser, or he may get a visit from the ATF — that’s the US Bureau of Alcohol, Tobacco, and Firearms, who are way less fun to deal with than the name might imply.

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Railguns: Making Metal Go Fast Using The Lorentz Force

February 24, 2026 by 49 Comments

In science fiction, the use of gunpowder-based weapons is generally portrayed as something from a savage past, with technology having long since moved on to more civilized types of destructive weaponry, involving lasers, microwaves, and electromagnetism. Instead of messy detonating powder, energy-weapons are used to near-instantly deposit significant amounts of energy into the target, and railguns enable the delivery of projectiles at many times the speed of sound using nothing but the raw power of electricity and some creative physics.

Of course, the reason that we don’t see sci-fi weapons deployed everywhere has arguably less to do with today’s levels of savagery in geopolitics and more with the fact that physical reality is a very harsh mistress, who strongly frowns upon such flights of fancy.

Similarly, the Lorentz force that underlies railguns is extremely simple and effective, but scaled up to weapons-grade dimensions results in highly destructive forces that demolish the metal rails and other components of the railgun after only a few firings. Will we ever be able to fix these problems, or are railguns and similar sci-fi weapons forever beyond our grasp?

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PLA mail being tested against a sword

3D Printed Mail Is A Modern Solution To An Ancient Problem

November 13, 2025 by 25 Comments

The human body and sharp objects don’t get along very well, especially when they are being wielded with ill-intent. Since antiquity there have been various forms of armor designed to protect the wearer, but thankfully these days random sword fights don’t often break out on the street. Still, [SCREEN TESTED] wanted to test the viability of 3D printed chain mail — if not for actual combat, at least for re-enactment purposes.

He uses tough PLA to crank out a bed worth of what looks like [ZeroAlligator]’s PipeLink Chainmail Fabric, which just so happens to be the trending result on Bambu’s MakerWorld currently. The video shows several types of mail on the printer, but the test dummy only gets the one H-type pattern, which is a pity — there’s a whole realm of tests waiting to be done on different mail patterns and filament types.

In any case, the mail holds up fairly well to puncture from scissors and screwdrivers — with a heavy sweater or proper gambeson (a quilted cloth underlayer commonly worn with armor) on underneath, it looks like it could actually protect you. To slashing blows, PLA holds up astoundingly well, barely marked even by slashes from an actual sword. As for projectiles, well, everyone knows that to an arrow, chain mail is made of holes, and this PLA-based armor is no different (as you can see at 8:30 in the video below).

If you want to be really safe when the world goes Mad Max, you’d probably want actual chain mail, perhaps from stainless steel. On the other hand, if someone tries to mug you on the way home from a con, cosplay armor might actually keep you safer than one might first suspect. It’s not great armor, but it’s a great result for homemade plastic armor.

Of course you’d still be better off with Stepahnie Kwolek’s great invention, Kevlar.

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A green box with the answer to if a nuke has gone off with red neon lights

Has A Nuke Gone Off? Indicator

June 22, 2025 by 23 Comments

Look out of a window, ask yourself the question, “Has a nuke gone off?”. Maybe, maybe not, and all of us here at Hackaday need to know the answer to these important questions! Introducing the hasanukegoneoff.com Indicator from [bigcrimping] to answer our cries.

An ESP32 running a MicroPython script handles the critical checks from hasanukegoneoff.com for any notification of nuclear mayhem. This will either power the INS-1 neon bulb, indicating “no” or “yes” in the unfortunate case of a blast. Of course, there is also the button required for testing the notification lights; no chance of failure can be left. All of this is fitted onto a custom dual-sided PCB and placed inside a custom 3D-printed enclosure.

Hasanukegoneoff.com’s detection system, covered before here, relies on an HSN-1000L Nuclear Event Detector to check for neutrons coming from the blast zone. [bigcrimping] also provides the project plans for your own blast detector to answer the critical question of “has a nuke gone off” from anywhere other than the website’s Chippenham, England location.

This entire project is open sourced, so keep sure to check out [bigcrimping]’s GitHub for both portions of this project on the detector and receiver. While this project provides some needed dark humor, nukes are still scary and especially so when disarming them with nothing but a hacksaw and testing equipment.

Thanks to [Daniel Gooch] for the tip.