While VR is becoming really immersive, it still can’t compete with a game of good old laser tag to get the blood pumping and spending quality time with friends. [Xasin] has been working on a DIY laser tag system for a while now, and it has grown to include an impressive array of features and customizability.
Named LZRTag, the project started back in 2018 with simple ATmega328 based prototypes on breadboards. It has since evolved to a fully-featured system with ESP32s in the 3D printed pistol communicating with a Raspberry Pi/Linux game server over MQTT. Each pistol also features an accelerometer, I2S audio amp and speaker for game sounds, and WS2812 RGP LEDs for light effects. IR Lasers are used as emitters to target wearable IR receivers with more RGB LEDs wired to the pistol.
A Ruby server on a Linux machine takes care of all the communications, game management, shot validation, and scoring. It can handle up to 255 players and is designed to be extremely customizable for game modes, weapons classes, or any other feature you would like to have. [Xasin] has also created IR beacons to add even more possibilities, such as capture the flag, safe zones, and revive zones.
Humanity is another step closer to a fantasy-accurate lightsaber thanks to Hackaday alumnus [James Hobson] at Hacksmith. Their proto-saber cuts through (cosplay) stormtrooper armor, (foam) walls, and a (legit!) 1/4″ (6.35mm) steel plate. For so many reasons, we want to focus on the blade and handle. (Video, embedded below.)
The blade is a plasma stream designed for glassworking and burns a propane/oxygen mix with almost no residue, but the “blade” stays in a tight cylinder shape. With a custom PCB hosting a mixing controller, the blade extends and retracts like in the movies. The handle is not a technical marvel; it is an artistic wonder and if you want to see some machining eye-candy, check out the first video after the break. The second video demonstrates just how much damage you can do with a 4000° Fahrenheit tube of portable plasma.
You won’t be dueling anyone just yet, since there is no magnetic field shaping the blade like the ones [Lucas] envisioned. Unfortunately, you can’t block anything more substantial than a balloon sword since solid material will pass right through it, but it will suffer a mighty burn in the process. Lightsabers are a fantasy weapon, but the collective passion of nerds have made it as real as ever, and the Guinness folks give credibility to this build.
Compound bows (unlike recurve bows, their more mechanically-simple relatives) use a levering system with pulleys and spring tension to grant the user a mechanical advantage. We’re not exactly sure what to call [Zünder’s] bow design. He shared his unconventional take on a DIY bow that uses coiled springs as well as some other unique features.
What we really dig about [Zünder]’s design is how easy it is to grasp how it all works. As he demonstrates using the bow, the way the levers, pulleys, and spring tension all work together is very clear. The 3D-printed quiver and arrow rest are nice added touches, and we especially love the use of three toothbrush heads to provide contained support for a nocked arrow. The ring of bristles are sturdy enough to easily support the shaft, and don’t interfere with the arrow’s fletching.
Over the last century, very little of the basic design of firearm cartridges has changed, but the mechanics of firearms themselves have undergone many upgrades. The evolution of triggers, safeties, magazines, and operating mechanisms is a fascinating field of study. Hands-on experience with these devices is rare for most people, but thanks to people like [zvc], you can 3D print accurate replicas of historical firearms and see how all the parts fit together for yourself.
[zvc] is slowly building up a library of 3D models, with nine available so far, from the Mauser C96 “Broomhandle” pistol to the modern M4 rifle. Except for springs and some fasteners, almost every single part of [zvc]’s models are 3D printed, down to the takedown pins and extractors. With the obvious exception of being able to fire a live round, it looks like all the components fit and work together like on the real firearms. None were ever designed with 3D printing in mind, so a well-tuned printer, lots of support structure, and post-processing are required to make everything work. The surface finish will be a bit rough, and some smaller and thin-walled components might be susceptible to breaking after the repeated operation or excessive force. The models are not free, but all prices are below €10.
These models do demonstrate one of the real superpowers of 3D printing: functional mock-ups and prototypes. The ability to do rapid iterative design updates and to have the latest design in hand within a few hours is invaluable in product development. [Giaco] used this extensively during the development of his kinetic driver. When you buy 3D printable models online, always make sure what possible pitfalls exist.
When professional engineers are giggling like kids, you know something interesting is about to happen. [Destin Sandlin] of [Smarter Every Day], [Jeremy Fielding], and a few other like-minded individuals have built a very impressive air cannon, capable of launching baseballs at supersonic velocities.
The muzzleloading canon consists of a large pressure chamber and vacuum chamber stuck together, with a plug and baseball separating the two. The barrel forms part of the vacuum chamber, and is sealed off at the muzzle end with plastic tape that ruptures when fired. The firing mechanism runs the entire length of the pressure chamber, exiting out the back where it is held in place by a large pneumatic sear mechanism. When the sear is released, it “pops the cork” between the two chambers, sending high-pressure nitrogen into the vacuum chamber, forcing the ball forward. This causes the plug rod to shoot out the back of the pressure chamber, where it is stopped by a pneumatic piston. The entire thing is permanently mounted on a trailer. A professional-looking control box is used to operate the beast from behind the safety of a steel blast shield.
Be sure to watch the videos after the break with subtitles turned on. The first is the highlights reel, and the second is a very entertaining hour-long behind the scenes look. To the surprise of the builders, they were able to shoot a baseball at Mach 1.38 (1050 mph or 1690 km/h) on the very first try, with only a partially pressurized system and a leaking vacuum chamber. When impacting the thick steel target, the ball disintegrates completely, imprinting its stitches on the target. [Destin] and co recorded the results with his usual high-speed cameras, but also included a Schlieren rig that allowed them to photograph the shock waves and Mach cones generated by the speeding ball. After a few shots, the bolts were stripped out of the pneumatic piston that stops the plug rod, which is no surprise judging by how much the steel frame flexes in that area. Continue reading “Making Baseballs Go Supersonic”→
To make up for some lacking athletic ability, [Shane Wighton] of [Stuff Made Here] created a custom baseball bat with an explosive sweet spot, that almost guarantees a home run. Inside a custom machined bat, he added a piston mechanism, powered by blank cartridges intended for powder actuated nailers, that can hit a ball with impressive force.
Up to three rimfire blank cartridges are placed in the stationary side of the piston mechanism, and are fired by three firing pins on the back of the piston when a ball hits the front of the piston. The expanding gasses then drive the piston out at high velocity, hitting the ball, before it is stopped from flying out completely by a crossbar. The gasses are exhausted through the side of the sleeve, into a “muffler” machined into the front of the bat. The first time [Shane] fired the mechanism with two cartridges, it almost sheared off the stopping bar, and damaged all the other components and blew the bat apart. This led to a complete redesign, including a crossbar with urethane dampers and an aluminum muffler.
The results with the “upgrades” are pretty impressive, and a little scary. Batting distance was around 350 feet with two cartridges, hitting the ball off a tee to avoid putting a pitcher in the firing line. [Shane] did a lab test with three cartridges, which put a hole in the ball and looked like it would break the bat. He expects that three cartridges would allow him to break the home run record, but would require another redesign and will be left for a future video
What has dual compressed-air cannons, 500 roll-on deodorant balls, and a machine-learning brain with a bad attitude? We didn’t know either, until [Leo Fernekes] dropped this video on his autonomous robot sentry gun and saw it in action for ourselves.
Now, we’ve seen tons of sentry guns on these pages before, shooting everything from water to various forms of Nerf. And plenty of those builds have used some form of machine vision to aim the gun onto the target. So while it might appear that [Leo]’s plowing old ground here, this build is chock full of interesting tips and tricks.
It started when [Leo] saw a video on TensorFlow basics from our friend [Edje Electronics], which gave him the boost needed to jump into an AI project. The controller he ended up with looks for humans in the scene and slews the turret onto target, where the air cannons can do their thing. The hefty ammo is propelled by compressed air, which is dumped into the chamber using a solenoid valve with an interesting driver that maximizes the speed at which it opens. Style points go to the bacteriophage T4-inspired design, and to the sequence starting at 1:34 which reminded us of the factory scene from RoboCop.
[Leo] really put a ton of work into this project, and the results show. He is hoping to get an art gallery or museum to show it as an interactive piece to comment on one possible robot-human future, presumably after getting guests to sign a release. Whatever happens to it, the robot looks great and [Leo] learned a lot from it, as did we.