I am a fan of the saying that those who don’t know history are doomed to repeat it. After all, humans have been building things for a number of centuries and we should learn from the engineers of the past. While you can learn a lot studying successes, sometimes — maybe even most of the time — we learn more from studying failure. The US Navy’s Mark 14 torpedo certainly has a lot to teach us.
The start of the story was the WWI-era Mark 10 torpedo which was fine for its day, but with faster destroyers and some additional data about how to best sink enemy ships it seemed necessary to build a new torpedo that would be faster, carry more explosive charge, and use a new method of detonation. Work started in 1931 with a $143,000 budget which may sound laughable today, but that was a lot of coin in the 1930s. Adjusted for inflation, that’s about $2.5 million.
[Dirk] shared a fascinating project of his that consists of several different parts coming together in a satisfying whole. It’s all about wanting to do target practice, indoors, using a simple red laser dot instead of any sort of projectile. While it’s possible to practice by flashing a red laser pointer and watching where it lands on a paper target, it’s much more rewarding (and objective) to record the hits in some way. This is what led [Dirk] to create human-powered, battery-free laser guns with software to track and display hits. In the image above, red laser hits on the target are detected and displayed on the screen by the shooter.
Right under the thumb is the pivot point for the lever, and that’s also where a geared stepper motor (used as a generator) is housed. Operating the action cranks the motor.
There are several parts to this project and, sadly, the details are a bit incomplete and somewhat scattered around, so we’ll go through the elements one at a time. The first is the guns themselves, and the star of the show is his 3D printed cowboy rifle design. The rifle paints the target with a momentary red laser dot when the trigger is pressed, but that’s not all. [Dirk] appears to have embedded a stepper motor into the lever action, so that working the lever cranks the motor as a generator and stores the small amount of power in a capacitor. Upon pulling the trigger, the capacitor is dumped into the laser (and into a piezo buzzer for a bit of an audio cue, apparently) with just enough juice to create a momentary flash. We wish [Dirk] had provided more details about this part of his build. There are a few more images here, but if you’d like to replicate [Dirk]’s work it looks like you’ll be on your own to some extent.
As for the target end of things, blipping a red dot onto a paper target and using one’s own eyeballs can do the job in a bare minimum sort of way, but [Dirk] went one further. He used Python and OpenCV with a camera to watch for the red dot, capture it, then push an image of the target (with a mark where the impact was detected) to a Chromecast-enabled screen near the shooter. This offers much better feedback and allows for easier scoring. The GitHub repository for the shot detector and target caster is here, and while it could be used on its own to detect any old laser pointer, it really sings when combined with the 3D printed cowboy rifle that doesn’t need batteries.
Not using projectiles in target practice does have some benefits: it’s silent, it’s easy to do safely, there is no need for a backstop, there are no consumables or cleaning, and there is no need to change or patch targets once they get too many holes. Watch it all in action in the video embedded below.
In these troubled times, when a trip to the grocery store could turn into a brawl over toilet paper, you might be inclined to build yourself a low-cost electroshock weapon. Or at least, that’s what [Alex Zidros] did. We don’t necessarily recommend you follow in his footsteps, and we’re certainly not advocating testing it on a loved one. We just bring you this information, you have to decide what you do with it.
This is what peer pressure looks like.
So what does it take to build an improvised stun gun? Not a whole lot, it turns out. As you might have guessed, the star of the show is a high voltage transformer which supposedly puts out 400 kV. Just looking at it (and the price) we’re going to go out on a limb and say the performance specs are way overrated, but in this case that might actually be a good thing.
Beyond the transformer, there’s a simple 9 V battery holder and electrodes made from the prongs of a hacked up travel adapter. To deliver the lightning, [Alex] is using a pink arcade button. Just because you might be fighting for your life doesn’t mean you can’t have a little fun, right? Everything is packed into a simple 3D printed enclosure, but you could easily replace that with any suitably sized box. Something made out of wood might be a good idea, considering.
If you’d like to see another person shocked by a cobbled together high-voltage weapon, and potentially even learn something in the process, check out the “tutorial” video [Mehdi Sadaghdar] did back in 2014. We did mention you definitely shouldn’t do this at home, right?
There was something exceptionally satisfying about those playground games of cops and robbers when we were young, but they were missing something in that a pretend gun made with your fingers lacks a certain Je ne sais quoi. Our youthful blood-lust demanded something a bit more real, and though the likes of NERF and other toys could supply it their lost projectiles came at a price not all parents could sustain. We’d have given anything for [Brick Experiment Channel]’s rapid-firing Lego playing card gun! (Video, embedded below.)
The principle is simple enough, one of the larger Lego road wheels is spun up to a respectable speed through a gear train from a pair of motors, it’s positioned over a channel through which playing cards are fed, and it picks each one up and accelerates it to a claimed 20 miles per hour. The card is fired off into the distance, ready to take down your Lego figure or plastic drinking cup enemies with maximum prejudice.
It’s clear some significant thought has gone into the firing platform design, with the cards sliding along smooth rails and the wheel sitting in a gap between the rails so that the natural springiness of the card can engage with it. The cards also emerge with a spin, due to the wheel being offset. The mechanism is completed with a third motor which acts as a feeder pushing individual cards from the deck into the main firing platform. This achieves an astonishing six cards per second, as can be seen in the video below the break.
We can see that this is a huge amount of fun, and we hope should any youngsters get their hands on it that there are not lurid tales of kids with playing card injuries. It’s not the first novelty projectile gun we’ve brought you, there have been numerous rubber band guns but our favourite is the automatic paper plane folder and launcher.
From the Age of Sail through to the Second World War, naval combat was done primarily in close quarters and with cannons. Naturally the technology improved quite a bit in those intervening centuries, but the idea was more or less the same: the ship with the most guns and most armor was usually the one that emerged victorious. Over the years warships became larger and heavier, a trend that culminated in the 1940s with the massive Bismarck, Iowa, and Yamato class battleships.
But by the close of WWII, the nature of naval combat had begun to change. Airplanes and submarines, vastly improved over their WWI counterparts, presented threats from above and below. A few years later, the advent of practical long-range guided missiles meant that adversaries no longer had to be within visual range to launch their attack. Going into the Cold War it became clear that to remain relevant, warships of the future would need to be smaller, faster, and smarter.
The aft flight deck of a modular LCS
It was this line of thinking that lead the US Navy to embark on the Littoral Combat Ship (LCS) program in the early 2000s. These ships would be more nimble than older warships, able to quickly dash through shallow coastal waters where adversaries couldn’t follow. Their primary armament would consist of guided missiles, with fast firing small-caliber guns being relegated to defensive duty. But most importantly, the core goal of the LCS program was to produce a modular warship.
Rather than being built for a single task, the LCS would be able to perform multiple roles thanks to so-called “mission modules” which could be quickly swapped out as needed. Instead of having to return to home port for a lengthy refit, an LCS could be reconfigured for various tasks at a commercial port closer to the combat area in a matter of hours.
A fleet of ships that could be switched between combat roles based on demand promised to make for a more dynamic Navy. If the changing geopolitical climate meant they needed more electronic reconnaissance vessels and fewer minesweepers, the Navy wouldn’t have to wait the better part of a decade to reshuffle their assets; the changeover could happen in a matter of weeks.
During the Second World War, the United States was pumping out weapons, aircraft, and tanks at an absolutely astonishing rate. The production of military vehicles and equipment was industrialized like never before, and with luck, never will be again. But even still, soldiers overseas would occasionally find themselves in unique situations that required hardware that the factories back at home couldn’t provide them with.
A Stinger machine gun in WWII
Which is precisely how a few United States Marines designed and built the “Stinger” light machine gun (LMG) during the lead-up to the invasion of Iwo Jima in 1945. The Stinger was a Browning .30 caliber AN/M2, salvaged from a crashed or otherwise inoperable aircraft, that was modified for use by infantry. It was somewhat ungainly, and as it was designed to be cooled by the air flowing past it while in flight, had a tendency to overheat quickly. But even with those shortcomings it was an absolutely devastating weapon; with a rate of fire at least twice that of the standard Browning machine guns the Marines had access to at the time.
Six Stingers were produced, and at least on a Battalion level, were officially approved for use in combat. After seeing how successful the weapon was during the invasion of Iwo Jima, there was even some talk of putting the Stinger into larger scale production and distributing them. But the war ended before such a plan could be put into place.
As such, the Stinger is an exceedingly rare example of a field modified weapon that was not only produced in significant numbers, but officially recognized and even considered for adoption by the military. But the story of this hacked machine gun actually started years earlier and thousands of kilometers away, as Allied forces battled for control of the Solomon Islands.
The would-be invader of a mediaeval kingdom could expect to face some stern opposition from a variety of formidable weaponry. Making modern versions of these deadly curiosities seems to be a popular pursuit, and the bug has bitten [Turbo Conquering Mega Eagle], who’s created what he calls a “Stonebow”, a crossbow on steroids that fires stones or large ball bearings with considerable force.
It uses a couple of leaves from automotive springs, mounted in a welded steel riser with two strings and a pouch for the projectile. The barrel is an oak fencing post, and at its other end is a cocking lever which also forms a stock, and a cleverly designed trigger mechanism. The projectile is loaded, the bow is cocked, and it is fired at a scrap Land Rover radiator in which it places a satisfying impact mark.
Despite two successful firings it’s evident that so much force isn’t easy to contain. The crimps that secure the strings aren’t up to the job, and neither is the oak fence post, which has cracked at the end. We trust that our Essex hacker friend will return having fixed these flaws, and more defenceless scrap car parts will be sacrificed for our entertainment.
We’ve featured [Turbo Conquering Mega Eagle] before, most recently building a mini-bike for his youngsters. Meanwhile, enjoy the Stonebow in the video below the break.
