Hefty 3D Printed Quadcopter Meets Nasty End

You can readily buy all kinds of quadcopters off the shelf these days, but sometimes it’s more fun to build your own. [Michael Rechtin] did just that, with a hefty design of his own creation.

The build is an exploration of all kinds of interesting techniques. The frame itself uses generative design techniques to reduce weight while maintaining strength, while the motors themselves make heavy use of 3D-printed components. The design is modular and much of it slots together, too, and it uses a homebrewed flight controller running dRehmflight. It draws 2.5 kW from its lithium polymer batteries and weighs over 5 kg.

The DIY ethos led to some hurdles, but taught [Michael] plenty along the way. Tuning the PID control loop posed some challenges, as did one of the hand-wound motors being 5% down on thrust.  Eventually, though, the quad flew well enough to crash into a rectangular gate, before hitting the ground. Any quad pilot will tell you that these things happen. Drilling into the quad with a battery still inside then led to a fire, which did plenty of further damage.

[Michael’s] quad doesn’t appear to be specifically optimized to any one task, and it’s easy to see many ways in which it could be lightened or otherwise upgraded. However, as a freeform engineering thinking exercise, it’s interesting to watch as he tackles various problems and iteratively improves the design. Video after the break.

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Big 3D Printed Hand Uses Big Servos, Naturally

[Ivan Miranda] isn’t afraid to dream big, and hopes to soon build a 3D printed giant robot he can ride around on. As the first step towards that goal, he’s built a giant printed hand big enough to hold a basketball.

The hand has fingers with several jointed segments, inspired by those wooden hand models sold as home decor at IKEA. The fingers are controlled via a toothed belt system, with two beefy 11 kg servos responsible for flexing each individual finger joint. A third 25 kg servo flexes the finger as a whole. [Ivan] does a good job of hiding the mechanics and wiring inside the structure of the hand itself, making an attractive robot appendage.

As with many such projects, control is where things get actually difficult. It’s one thing to make a robot hand flex its fingers in and out, and another thing to make it move in a useful, coordinated fashion. Regardless, [Ivan] is able to have the hand grip various objects, in part due to the usefulness of the hand’s opposable thumb. Future plans involve adding positional feedback to improve the finesse of the control system.

Building a good robot hand is no mean feat, and it remains one of the challenges behind building capable humanoid robots. Video after the break.

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Emulating X86 On Apple’s AARCH64 X64 Emulator

You might know [Evan Martin] as the developer of retrowin32. It’s a Windows and x86 emulator designed to run on a Mac or on the web. He’s recently been exploring how to run 32-bit x86 binaries on the AArch64 (aka ARM64) architecture.

[Evan] realized that Apple’s ARM-based Macs feature a high-quality x86 emulator, used via the Rosetta binary translation system. It only supports 64-bit x86-64 binaries, also known as x64, and thus he had initially discounted it for running older 32-bit x86 software. However, as it turns out, x64 features a special compatibility mode for running 32-bit code. [Evan] was able to leverage this to run 32-bit Windows executables rather neatly via the high-performance Rosetta emulator.

To run a 32-bit executable on a 64-bit processor in this way, one creates a 64-bit program that is tasked with loading the 32-bit executable. It’s a little fussy, involving some tricks to handle memory management between the 32-bit code and the 64-bit wrapper, and how to interface with the OS, but [Evan] explains deftly how it’s all done.

[Evan] notes that this hack may not work forever, especially if Apple changes or deprecates Rosetta’s remaining x86-64 emulation in the future. Regardless, Apple’s “Game Porting Toolkit” relies on similar techniques used by Wine. If you find yourself dancing across platforms, you might learn some nifty tricks from [Evan]’s example!

Hoverboard Turned Into Bonkers Omniwheeled Bike

Segways stunned the world when they first hit the market in 2001. Hoverboards then terrified the world with nasty accidents and surprise fires. [James Bruton] loves hoverboards regardless, and set out on a mighty upgrade regime turning the ride-on toy into a giant omniwheeled bicycle.

The build relies on two giant omniwheels of [James’s] own creation, using lasercut and 3D-printed parts. The wheels are mounted perpendicularly on either end of a boxy plywood “bike frame” built in two sections, with a split in the middle. The two halves can rotate relative to each other, much like the two halves of a stock hoverboard.

Amazingly, the build relies on the stock hoverboard motors and electronics. The hoverboard wheel motors are responsible for driving the omniwheels at either end via a toothed belt drive. The gear ratio of the belt reduction is set up to cancel out the greater diameter of the omniwheels, such that the hoverboard’s tuning isn’t disrupted. Wisely, [James] also fitted a safety power cutout, too.

The result is a self-balancing “bike” the likes of which you’ve never seen before. At present, it can balance upright and rotate relatively well. However, control is difficult, requiring the use of the rider’s body weight and the twisting of the bike’s sections. [James] has instead contemplated using servos to tilt the hoverboard sensors instead for an easier control method than the current setup.

It’s a truly bonkers build which is a testament to [James’s] creativity and prowess. We’ve seen some other great hoverboard hacks before, but nothing quite like this. Video after the break.

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The Neo6502 Is A Credit-Card Sized Retro Computer

The venerable MOS Technology 6502 turned up in all kinds of computers and other digital equipment over the years. Typically, it was clocked fairly slow and had limited resources, but that was just how things used to be. Today, the 6502 can run at an altogether quicker pace, and the Neo6502 was the board built to take it there.

The Neo6502 from [Olimex] is a credit-card sized retro computer built around the W65C02. If you’re unfamiliar with that chip, it’s essentially a 6502 that can go fast. How fast? It can be readily overclocked to a blazing 16 MHz, if you’re so inclined!

Unlike some 6502 retro builds, the Neo6502 doesn’t live so firmly in the past. It’s outfitted with an HDMI video interface to make it easy to hook up to modern monitors, so you needn’t fuss around with old displays. Similarly, it has a USB host port to accept input from a keyboard, and audio out via a 3.5 mm jack. There’s also a tiny PCB-mount speaker, as well as I2C, SPI, and UART interfaces. Finally, there’s 2 MB of flash onboard, and a 40-pin connector hosting all the 6502 signals that you know and love. Which is all of them. Much of this lavish equipment comes courtesy of an RP2040 microcontroller onboard that handles all the bits and bobs that aren’t fit for the CPU itself.

It’s still a new project, with things like a BASIC interpreter currently in development and boards not yet openly available.  But, if you’ve always wanted to play with a hotshot 6502, this could be the board for you. Try out the emulator and see how you go.

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Why Are We Only Just Now Hearing About LED Beaded Curtains

Beaded curtains are a pretty banal piece of home decor, unlikely to excite most interior design enthusiasts. Throw on some addressable LEDs, though, and you’ve got something eye-catching at the very least, as [Becky] demonstrates.

Joining the LED strands at the bottom made running the wiring easy but made walking through the blinds hard.

The project started with an existing beaded curtain as a base. A series of addressable LED strands were then carefully sewn to the beads using knots tied in plain sewing thread. The strands were configured as a single strand as far as the data lines were concerned, to make animation easy. Power was supplied to both ends of the strand to ensure nice and even brightness across the strands.

The brains of the system is a PixelBlaze controller, which makes it easy to wirelessly control the behavior of the strings. It’s the perfect tool for quickly whipping up fancy animations and pretty effects without hand-assembling a bunch of code yourself.

There was only a few problems with the project. [Becky] found a pretty passable LED beaded curtain from China midway through the project, which reduced her enthusiasm to finish the build. There were also issues walking through the curtain due to the wiring scheme she chose, where the bottom of one strand was connected to its neighbor.

Regardless, it’s a fun blinky build that brings some color to an otherwise drab doorway. It’s hard to complain about that! Video after the break.

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3D Printing RC Car Tires To Go Fast

There’s a bit of a high-speed arms race in the RC world on YouTube these days. [Michael Rectin] is in on the action, and he’s been exploring how to 3D print a decent set of tires to help his RC car reach higher speeds mph.

His first efforts involved experiments with TPU. The tires looked okay, but had very little traction. He later moved on to VarioShore TPU, a filament capable of delivering various properties depending on the printing method. Printing for the softest, and thus grippiest, possible tires, [Michael] whipped up some sporty looking boots for his wheels.

His tires improved over  off-road RC tires in one major way. His design didn’t suffer significant ballooning as the rotational velocity increased. However, the VarioShore material lacked grip compared to off-the-shelf rubber RC tires designed for high-speed use. The commercially-available tires also offered a smoother ride.

[Michael] also demonstrated some neat tricks for high-speed RC driving. He used a modified flight controller to correct the car’s steering in response to perturbations, and put in a scaling method that reduces steering inputs at higher speed. That didn’t entirely stop the carnage though, with some incidents seeing wheels thrown off in big tumbling crashes.

Electric-powered RC cars can go darn quick these days, but you might want to consider jet power if you want to break records. Video after the break.

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