Concrete Boat Cements Its Way To High Speeds

November 11, 2022 by Ryan Flowers 12 Comments

Steel is scarce. Wood is not an option. And you need a boat now. These wartime circumstances drove innovation in all kinds of crazy directions, and one somewhat less crazy direction — concrete boats. As [Peter Sripol] demonstrates in the video below the break, making an RC concrete boat isn’t hard. Making a fast one on the other hand is. But that didn’t stop him from trying, and we think the effort deserves a look.

Starting with a basic displacement style hull, [Peter] and his cohorts experimented with a simple RC boat that worked, but could only move at slow speeds. They turned things up a notch or two and instead modeled their concrete boat after an RC speedboat hull that they had on hand.

The construction methods left a lot to be desired though, and they even tried various wire meshes as rebar, but they proved too heavy. Eventually though, they got a working hull, and had some fun with it. Rather than try to make the hull watertight with a rudder and propeller, they opted for a ducted fan and an airboat style rudder to make what they call the “world’s fastest concrete boat”.

Whether it’s the fastest or not is unconfirmed, but it is fast and actually gets on step fairly nicely. We applaud the exploration of alternative materials and the experimentation with different build methods. If building things with concrete floats your boat, then be sure to check out this concrete pinhole camera.

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This Wii Has An Apple M1 Inside

November 9, 2022 by Navarre Bartz 8 Comments

The conveniently tiny logic board of the M1 Mac mini has lead to it giving the Mini ITX format a run for its money in case mods. The latest example of this is [Luke Miani]’s M1 Wii. (Youtube via 9to5Mac)

[Miani] chose the Wii as a new enclosure for this Mac mini given its similar form factor and the convenient set of doors in the top to maintain access to the computer’s I/O, something he wasn’t able to do with one of his previous M1 casemods. The completed build is a great stealth way to have a Mac mini in your entertainment center. [Miani] even spends the last several minutes of the video showing the M1 Wii running Wii, GameCube, and PS2 games to really bring it full circle.

A Microsoft Surface power brick was spliced into the original Wii power cable since the Wii PSU didn’t have enough wattage to supply the Mac mini without significant throttling. On the inside, the power runs through a buck converter before making its way to the logic board. While the Mini’s original fan was too big to fit inside the Wii enclosure, a small 12V fan was able to keep performance similar to OEM and much higher than running the M1 fanless without a heat spreader.

If you’d like to see some more M1 casemods, check out this Lampshade iMac or the Mac Mini Mini.

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End Of An Era, As LEGO To Discontinue Mindstorms

November 3, 2022 by Jenny List 46 Comments

When there are so many single board computers and other products aimed at providing children with the means to learn about programming and other skills, it is easy to forget at time before the Arduino or the Raspberry Pi and their imitators, when a computer was very much an expensive closed box.

Into this late-’90s vacuum left in the wake of the 8-bit home computer revolution came LEGO’s Mindstorms kits, a box of interlocking goodies with a special programmable brick, which gave kids the chance to make free-form computerized robotic projects all of their own. The recent news that after 24 years the company will discontinue the Mindstorms range at the end of the year thus feels like the end of an era to anyone who has ridden the accessible microcontroller train since then.

What became Mindstorms has its roots in the MIT Media Lab’s Programmable Brick project, a series of chunky LEGO bricks with microcontrollers and the Mindstorms LEGO brick contacts for motors and sensors. Their Logo programming language implementation was eschewed by LEGO in favor of a graphical system on a host computer, and the Mindstorms kit was born. The brand has since been used on a series of iterations of the controller, and a range of different robotics kits.

In 1998, a home computer had morphed from something programmable in BASIC to a machine that ran Windows and Microsoft Office. Boards such as Parallax’s BASIC Stamp were available but expensive, and didn’t come with anything to control. The Mindstorms kit was revolutionary then in offering an accessible fully programmable microcontroller in a toy, along with a full set of LEGO including motors and sensors to use with it.

We’re guessing Mindstorms has been seen off by better and cheaper single board computers here in 2022, but that doesn’t take away its special place in providing ’90s kids with their first chance to make a proper robot their way. The kits have found their place here at Hackaday, but perhaps most of the projects we’ve featured using them being a few years old now underlines why they are to meet their end. So long Mindstorms, you won’t be forgotten!

Header image: Mairi, (CC BY-SA 3.0).

Exploring Piston Engine Design With LEGO

November 1, 2022 by Danie Conradie 16 Comments

When learning about the design of a machine or mechanism, reading and watching videos is certainly effective, but it’s hard to beat hands-on experimentation. In the video after the break, [Brick Technology] uses LEGO to gain some practical insight into the world of piston engine design, from single-cylinder all the way up to radial twelve-cylinder engines.

Using pneumatic cylinders from the LEGO Technic series, [Brick Technology] starts by getting the basics working with a single-cylinder design. Besides the fact that there are no fuel-air explosions involved, these pistons are also double-acting thanks to a valve mechanism that switches the pressurized side of the piston as it reaches the end of its stroke. After a couple of experiments, he settles on using a bank of six two liter soda bottles as a source of pressurized air.

He also increased the performance of the LEGO cylinders by drilling out the ports and adding silicon oil for lubrication. In the initial prototypes, the cylinders also acted as connecting rods, tilting back and forth as the crankshaft rotates. After some testing, he discovered he could increase efficiency by constraining the cylinder with a slider mechanism and adding a separate connecting rod.

With the basics done, [Brick Technology] could start experimenting with engine arrangements and geometry. Inline two, three, and four cylinders and V2, V6, V8, and even R12 were all on the menu. He could also change crankshaft geometry to trade torque for RPM and vice versa, and build a starter motor, and torque generator.

Just like [Brick Technology]’s LEGO electronic drums and vortex machine, this video gives us a itch that can only be scratched by a few hundred LEGO pieces. For rapid prototyping of course.

This Computer Is Definitely Not A Toy

September 30, 2022 by Jenny List 6 Comments

If you’ve ever eyed up a kids laptop and wondered whether it could take an upgrade with a single board computer, you’re not alone. [Labz] have taken a couple of Brazilian Max Steel toy computers from a decade or more ago, and made them into usable if unconventional portable computers (Brazilian Portuguese, but YouTube’s subtitle translation is your friend).

The computers are similar to the ones you may be familiar with from the likes of VTech, a QWERTY keyboard and fairly conventional form factor but with a tiny monochrome LCD and a few built-in games. In the video below the break we see both the laptop and desktop variants butchered with a rotary tool to receive new larger screens, with the laptop getting a Raspberry Pi and the desktop getting a small form factor PC. The laptop needed a 3D printed extension to make extra space, while the desktop received a PCI Express extension cable for a video card. Finally, an Arduino took care of the keyboard.

The cherry on the cake for this video comes at the end, when they find the now-grown-up kid from the original advert. Meanwhile, kids computers have featured here before a few times.

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Ride-on Star Wars Land Speeder Gets A Real Jet Engine

September 20, 2022 by Lewin Day 11 Comments

When it comes to children’s ride-on toys, the Star Wars Land Speeder is one of the cooler examples out there. However, with weedy 12-volt motors, they certainly don’t move quickly. [Joel Creates] decided to fix all that, hopping up his land speeder with a real jet engine.

First, the original drivetrain was removed, with new wheels installed underneath. Initially, it was set up with the front wheels steering, while the rear wheels were left to caster freely. A RC jet engine was installed in the center engine slot on the back of the land speeder, and was controlled via a standard 2-channel RC transmitter.

The jet engine worked, but the wheel configuration led to the speeder simply doing donuts. With the speeder reconfigured with rear wheels locked in place, the speeder handled much more predictably. Testing space was limited to a carpark, so high-speed running was out of the question. However, based on the limited testing achieved, it looks as though the speeder would be capable of a decent clip with the throttle maxed out.

It’s not a practical build, but it sure looks like a fun one. [Joel Creates] has big dreams of adding two more jet engines and taking it out to a runway for high-speed testing, and that’s something we’d love to see.

RC jet engines are a bit of a YouTube fad right now, showing up on everything from RC cars to Teslas. Video after the break.

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Scratch-Built RC Excavator Is A Model Making Tour De Force

September 16, 2022 by Dan Maloney 20 Comments

Some projects just take your breath away with their level of attention to detail. This scratch-built RC-controlled model excavator is not only breathtaking in its detail, but also amazing for the materials and tools used to create it.

We’ve got to be honest, we’ve been keeping an eye on the progress [Vang Hà] has been making on this build for a few weeks now. The first video below is a full tour of the finished project, which is painstakingly faithful to the original, a Caterpiller 390F tracked excavator. As impressive as that is, though, you’ve got to check out the build process that starts with fabricating the tracks in the second video below. The raw material for most of the model is plain gray PVC pipe, which is sliced and diced into flat sheets, cut into tiny pieces using a jury-rigged table saw, and heat formed to create curved pieces. Check out the full playlist for a bounty of fabrication delights, like tiny hinges and working latches.

We can’t possibly heap enough praise onto [Vang Hà] for his craftsmanship, but that’s not all we love about this one. There are tons of helpful tips here, and plenty of food for thought for more practical builds. We’re thinking about that full set of working hydraulic cylinders that operates the boom, the dipper, and the bucket, as well as the servo-operated hydraulic control valves. All of it is made from scratch, of course, and mostly from PVC. Keep that in mind for a project where electric motors or linear actuators just won’t fill the bill.

If this construction technique seems familiar to you, it could because we featured a toolbox made out of similarly processed PVC pipes back in June.

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