The Egyptian Coin Box ‘Trick’

August 7, 2023 by Dave Rowntree 9 Comments

[James Stanley] likes to spend time making puzzles and gadgets for escape rooms, and decided for a change to try their hand at a bit of magic. The idea was to construct a ‘magic box’, in which a coin can be placed in one of a number of slots, and then be able to remotely be able to determine the slot by means unseen. Obviously, this is an electronics hack, with a neat package of sensor and radio comms hidden inside a stack of CNC-milled wood. Coin locations are transmitted via Bluetooth to a Bangle.js smartwatch, which vibrates according to the slot occupied, allowing [James] to predict where the coin was placed. Continue reading “The Egyptian Coin Box ‘Trick’” →

Making A Kid-Scale Apollo 11 Lunar Lander

August 5, 2023 by Donald Papp 21 Comments

If you’d like to see what goes into making a 1/3-scale Apollo 11 Lunar Module, [Plasanator]’s photos and build details will show off how he constructed one for a kid’s event that was a hit!

The photo gallery gives plenty of ideas about how one would approach a project like this, and readers will surely appreciate the use of an old frying pan as a concrete mold to create the lander’s “feet”. Later, a little paint makes the frying pan become a pseudo-antenna mounted on the lander’s exterior.

Inside, the lander has a control panel with a lot of arcade-style buttons and LED lighting. It’s pretty simple stuff, but livens things up a lot. Bright red lighting for the engine combined with a couple of slow strobe lights really makes it come alive in the dark. The gold foil? Emergency thermal blankets wrapped around the frame.

We happen to have the perfect chaser for this kid-scale lunar module: the Apollo 11 moon landing, recreated with animatronics and LEGO.

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What Does It Take For A LEGO Car To Roll Downhill Forever?

July 31, 2023 by Donald Papp 11 Comments

Cars (including LEGO ones) will roll downhill. In theory if the hill were a treadmill, the car could roll forever. In practice, there are a lot of things waiting to go wrong to keep this from happening. If you’ve ever wondered what those problems would be and what a solution would look like, [Brick Technology] has a nine-minute video showing the whole journey.

The video showcases an iterative process of testing, surfacing a problem, redesigning to address that problem, and then back to testing. It starts off pretty innocently with increasing wheel friction and adding weight, but we’ll tell you right now it goes in some unexpected directions that show off [Brick Technology]’s skill and confidence when it comes to LEGO assemblies.

You can watch the whole thing unfold in the video, embedded below. It’s fun to see how the different builds perform, and we can’t help but think that the icing on the cake would be LEGO bricks with OLED screens and working instrumentation built into them.

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A Nifty 3D Printed RC Car

July 27, 2023 by Lewin Day 9 Comments

Once upon a time, a remote controlled (RC) car was something you’d buy at Radio Shack or your local hobby store. These days, you can print your own, complete with suspension, right at home, as this project from [Logan57] demonstrates.

The design uses standard off-the-shelf hobby-grade components, with a brushed motor and controller for propulsion, and small metal gear servo for steering. The latter is a smart choice given there’s no servo saver in the design. Save for the fasteners and bearings, all the other parts are 3D printed. The hard components are produced in PETG or PLA, while flexible TPU is used for both the tires and the spring elements in the suspension system. It’s a double-wishbone design, and should serve as a good education should you later find yourself working on a Mazda Miata.

Building your own RC car isn’t just fun, it opens up a whole realm of possibilities. Sick of boring monster trucks and race cars? Why not build a 10×10 wheeler or some kind of wacky amphibious design? When you do, we’ll be waiting by the tipsline to hear all about it. Video after the break.

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3D-Printed RC Skid Steer Is Cute Construction Machinery Done Right

July 26, 2023 by Lewin Day 11 Comments

Skid steers are great fun if you get to drive one on a construction site. [ProfessorBoots] has long been a fan of the diminutive diggers, and decided to make a 3D-printed version for his own pleasure.

The build uses a chassis printed in several colors which adequately recreates the charms of a full-sized skid steer. The brains of the operation is an ESP32, which receives commands over WiFi for remote control. A pair of geared N20 brushed motors are driven from a small H-bridge controller, each one driving one side of the skid steer. A toothed belt was 3D printed to allow each motor to drive two wheels on one side. Meanwhile, a pair of servos are charged with both lifting and tilting the bucket. Yes, you heard correctly – you can actually pick up and carry objects around your desk with this thing.

It’s a neat build and could be your introduction into the world of RC construction machines. Video after the break.

Continue reading “3D-Printed RC Skid Steer Is Cute Construction Machinery Done Right” →

Hydroplaning Boat Skims Over Water

June 29, 2023 by Lewin Day 3 Comments

Regular hulled boats are all well and good for rowing and all, but if you wanna go fast, you’ve gotta cut your draft. [RCLifeOn] built a hydroplane design that skims on the very surface of the water, and thus travels very quickly as a result.

The build came about as [RCLifeOn] has an upcoming race which he wishes to win with speed and finesse. To that end, he 3D printed an RC hydroplane, using spray paint and spackle to waterproof the parts. It’s a trimaran design, with the large central hull connected to two pontoons via carbon fiber rods. Propulsion is via a triple-motor fan setup on the rear of the boat.

The outer motors were initially used to steer the boat via variable thrust, which comes with zero drag penalty compared to a conventional rudder. However, they proved ineffective, and a servo driven rudder was used instead. Eventually, all three motors were reconfigured for forward thrust.

The boat worked well when it was able to get up to speed and hydroplane over the surface of the water. However, it was difficult to film, as even the weight of a GoPro was enough to keep it stuck on the water’s surface. Instead [RCLifeOn] used his electric surfboard as a chase rig to film the boat — a neat trick itself. Continue reading “Hydroplaning Boat Skims Over Water” →

Escalate The NERF Arms Race With Self-Firing Missiles

June 27, 2023 by Jenny List 2 Comments

NERF guns are a toy that appeals to adults and youngsters alike — if you’ve never had the chance to pelt your friends with safe and kid friendly foam darts in a surprise ambush, you haven’t lived. But just as with real-world weapons of the type superpowers put in shows of military strength, there’s an arms race in the world of NERF. Mere darts aren’t enough, and there’s a range of missiles for the bellicose youngster intent on skirting the brink of global foam dart annihilation. These come with a catch though in the shape of a lackluster launcher, and this has prompted [Joel Creates] to create a self-firing NERF missile with a secondary rocket motor.

A supercapacitor stores enough energy to light a small scrap of guncotton explosive when sent through a heater coil, and this should be enough to launch the missile. Perhaps this whole video should sit in “Don’t try this at home kids” territory, but try he does, with multiple dead ends along the way. The final try is a secondary rocket motor inside the missile that’s triggered by a micro switch upon leaving the standard NERF launcher. It’s not a resounding success, but we’re sure you’ll agree it’s an entertaining video to get there.

We’ve featured quite a few NERF hacks over the years, including this large auto-aimer.

Continue reading “Escalate The NERF Arms Race With Self-Firing Missiles” →