Manned Multirotor Flies Again, Electric Style

July 1, 2017 by 85 Comments

You can’t keep a good hacker down. [Amazingdiyprojects] wants to build a reliable manned multirotor, and by golly, he’s doing it.  After a crash of his petrol powered design, [Amazingdiyprojects] went back to the drawing board. The new version is called chAIR, and is electric-powered.

The flying machine is lifted by 76 Multistar Elite quadcopter motors. Control is passed through 5 KK 2.1 quadcopter controllers. The KK board is a very simple controller, and we’re a bit surprised [Amazingdiyprojects] didn’t go with a newer setup. Batteries are 80x Multistar 4S 5.2Ah packs, stored below the seat. If these names sound familiar, it’s because just about every electrical part was purchased from Hobby King – an online hobby retailer.

The machine has an all up weight of 162 kg. A bit more than a single person can carry, but chAIR breaks down for easy transport.

We’re blown away by all the little details on chAIR – including the new control system. The left stick controls throttle, while right appears to control aileron/elevator and twist for the rudder control. Somewhat different from the collective/cycle controls found on conventional helicopters!

Even the battery connectors needed custom work. How do you connect 20 batteries at once? [AmazingDiyProjects] mounted XT60 connectors in a metal ring. The ring is compressed with a central screw. A quick spin with a battery-powered drill allows this new aviator to connect all his batteries at once. Is this the future of aviation, or is this guy just a bit crazy? Tell us in the comments!

Continue reading “Manned Multirotor Flies Again, Electric Style” →

The Breadboard RF103

July 1, 2017 by 13 Comments

When [ik1xpv] sets out to build a software-defined radio (SDR), he doesn’t fool around. His Breadboard RF103 sports USB 3.0, and 16-bit A/D converter that can sample up to 105 Msps, and can receive from 0 to 1800 MHz. Not bad. Thanks to the USB 3.0 port, all the signal processing occurs in the PC without the limitations of feeding data through a common sound port. You can see the device in action in the video below.

The Cypress FX3 USB device is an ARM processor, but it is only streaming data, not processing it. You can find the slightly modified firmware, a driver for using PC software, and schematics and board layouts on GitHub.

Continue reading “The Breadboard RF103” →

Custom Aluminum Wheels Teach A Thing Or Two About Casting

July 1, 2017 by 35 Comments

For some mobile projects like small carts or rolling cabinets, your standard casters from Harbor Freight will do just fine. But some projects need big, beefy wheels, and these custom cast aluminum wheels certainly make a statement. Mostly, “Watch your toes!”

To be honest, [Brian Oltrogge]’s wheels are an accessory in search of a project, and won’t be crushing feet anytime soon. He made them just to make them, but we have no beef with that. They’ve got a great look that hearkens back to a time when heavy metal meant something else entirely, and things were made to last. Of course, being cast from aluminum sort of works against that, but there are practical limits to what can be done in the home foundry. [Brian] started with a session of CAD witchcraft followed by machining the cores for his molds. Rather than doing this as lost foam or PLA, he milled the cores from poplar wood. His sand mix is a cut above what we usually see in home-brew sand casting — sodium silicate sand that can be cured with carbon dioxide. All his careful preparation meant the pour went off without a hitch, and the wheels look great.

We’ve featured quite a few metal casting projects recently, some that went well and some that didn’t. [Brian] looks like he knows what he’s doing, and we appreciate the workmanship that he puts on display here.

Continue reading “Custom Aluminum Wheels Teach A Thing Or Two About Casting” →

Launch Pad For Air-Water Rockets Is Good Clean Fun For STEM Students

July 1, 2017 by 24 Comments

We have fond memories of air-water rockets, which were always a dime store purchase for summertime fun in the pool. Despite strict guidance from mom to shoot them only straight up, the first target was invariably a brother or friend on the other side of the pool. No eyes were lost, and it was good clean fun that was mercifully free of educational value during summer break.

But now a teacher has gone and ruined all that by making an air-water rocket launching pad for his STEM students. Just kidding — [Robert Hart] must be the coolest teacher in Australia when Friday launch days roll around. [Mr. Hart] wanted a quick and easy way to safely launch air-water rockets and came up with a pretty clever system. The core task is to pump air into the partially filled water bottle and then release it cleanly. [Robert] uses quick-disconnect fittings, with the female coupling rigged to a motor through a bicycle brake cable. The control box has a compressor, the release motor, and a wireless alarm remote, all powered by a 12-volt battery. With the male coupling glued to the cap of a bottle acting as a nozzle and a quick, clean release, flights are pretty spectacular.

There are many ways to launch an air-water rocket, from the simple to the complex. [Robert]’s build leans toward the complex, but looks robust enough for repeated use and makes the launch process routine so the kids can concentrate on the aerodynamics. Or to just enjoy being outdoors and watching things fly.

Continue reading “Launch Pad For Air-Water Rockets Is Good Clean Fun For STEM Students” →

TMS9900 Retro Build

June 30, 2017 by 24 Comments

[Robert Baruch] found a TMS9900 CPU from 1983 in a surplus store. If that name doesn’t ring a bell, the TMS9900 was an early 16-bit CPU from Texas Instruments. He found that, unlike modern CPUs, the chip took several voltages and a four-phase twelve-volt clock. He decided to fire it up and — of course — one thing led to another and he wound up with a system on a breadboard. You can see one of the videos he made about the machine below.

This CPU had some odd features, most notably that it stored its registers in off-chip memory and can switch contexts by changing where the registers reside. That was a novel idea when the memory and the CPU were similar in speed. In a modern computer, the memory is much slower than the CPU and this would be a major bottleneck for program execution. The only onboard registers were the program counter, the status register, and a pointer to the general-purpose registers in memory.

Continue reading “TMS9900 Retro Build” →

3D-Printed Halbach Motor Part Two: Tuning, Testing

June 30, 2017 by 8 Comments

Building your own Halbach-effect brushless DC motor is one thing. Making sure it won’t blow up in your face another matter, and watching how [Christoph Laimer] puts his motor to the test is instructive.

You’ll remember [Christoph]’s giant 3D-printed BLDC motor from a recent post where he gave the motor a quick test spin. That the motor held together under load despite not being balanced is a testament to the quality of his design and the quality of the prints. But not wishing to tempt fate, and having made a few design changes, [Christoph] wisely chose to perform a static balancing of the rotor. He also made some basic but careful measurements of the motor’s parameters, including the velocity constant (Kv) using an electric drill, voltmeter, and tachometer, and the torque using a 3D-printed lever arm and a kitchen scale. All his numbers led him to an overall efficiency of 80%, which is impressive.

[Christoph] is shipping his tested BLDC off to the folks at FliteTest, where he hopes they put it to good use. They probably will — although they might ask for three more for a helicarrier.

Continue reading “3D-Printed Halbach Motor Part Two: Tuning, Testing” →

Gateway To Metal Casting

June 30, 2017 by 15 Comments

Casting is an exciting and very useful pastime, but it’s not exactly common these days. That’s a problem whether you’re just getting started or have been doing it for years: everyone can use the advice of another. Fear not! The US Department of Energy is here to help with the Industrial Metal’s Program’s Metal Casting cornucopia.

Although not strictly a hack, this is certainly a facilitator of hacks and any experienced user would do themselves some good by perusing the site. Click on the maps to find complex issues presented remarkably well for papers at this level of rigor. Seriously, check them out.

However, since these papers go into such depth, we can’t really say the material is beginner friendly. That’s not to say it would be bad for a newbie to read through, just that it might be a bit discouraging. But, if you need to figure out where to start in the maze of molds and sand and molten metal, we might have some articles that might help you out.

Do y’all know of any good casting resources on the interwebs? If so, leave ’em in the comments!

Thanks [RunnerPack] for sending this in.