Hackaday Links: February 4th, 2018

February 4, 2018 by Brian Benchoff 14 Comments

Here’s something remarkably displeasant. Can you cook a steak with glue? [Dom] and [Chris] from ExplosiveDischarge have cooked a steak using a huge, huge amount of two-part epoxy. The chemistry behind this is just the exothermic reaction when two-part epoxy kicks off, and yes, the steak (a very thin cut) was sufficiently wrapped and protected from the hot sticky goo. What were the results? An overcooked steak, actually. This isn’t a sous vide setup where the temperature ramps up to 50°C and stays there — the temperature actually hit 80°C at its peak. There are a few ways to fix this, either by getting a thicker cut of steak, adding some bizarre water cooling setup to keep the temperature plateaued at a reasonable temperature.

This is your weekly reminder for the Repairs You Can Print contest.

We’ve got a twofer for awesome remote-controlled hovering stuff. The first is a 1:8 scale Harrier. This plane designed and built by [Joel Vlashof] will be a reasonably accurate model of a Harrier, capable of VTOL. It’s built around a huge 130mm EDF, powered by 2x6s lipos, and stabilized with a kk2.1 flight controller with VTOL software. This is as accurate a Harrier that you’re going to get in such a small format, and has the cool little spinny vanes that allow the beast to transition from vertical to horizontal flight.

Want some more cool hovering things? [Tom Stanton] is building a remote controlled Chinook. Yes, that helicopter with two main rotors. The usual way of doing this is with proper helicopter control systems like collectives and Jesus nuts. [Tom]’s building this version with standard quadcopter technology, mounting a motor to a servo, and doubling it up, and mounting it on a frame. In effect, this RC Chinook is the tail boom of a tricopter doubled up on a single frame. It does fly, and he’s even built a neat foamboard body for it.

SpaceX’s Falcon Heavy is going to do something next Tuesday, sometime in the afternoon, east coast time. Whatever happens, it’s going to be spectacular.

Hey, it’s time for a poll. I need to decide between ‘tide pod’ and ‘solo jazz’. For what I’m doing, the cost and effort are the same, I just need to know which is more ａｅｓｔｈｅｔｉｃ, cool, or whatever. Right now it’s 50:50. One must be crowned victorious!

Here’s the stupidest thing you’re going to see all year. That’s someone looping a quadcopter in front of a Frontier A320 (Probably. Seems too big for a 319 and too small for a 321) on approach. This guy is 3.6 miles East of runway 25L at McCarran Internation in Las Vegas, at an altitude far above the 400-foot limit. Judging from the video and the wingspan, this quad came within 200 feet of a plane carrying at least 150 people. It’s the stupidest thing you’ve ever seen, so don’t do it. It’ll be great to see the guy responsible for this in jail.

Hackaday Links: January 21, 2018

January 21, 2018 by Brian Benchoff 17 Comments

You know what next week is? Sparklecon! What is it? Everybody hangs out at the 23b Hackerspace in Fullerton, California. Last year, people were transmuting the elements, playing Hammer Jenga, roasting marshmallows over hot resistors, and generally having a really great time. It’s the party for our sort of people, and there are talks on 3D projection mapping and a hebocon. I can’t recommend this one enough.

The STM32F7 is a very, very powerful ARM Cortex-M7 microcontroller with piles of RAM, oodles of Flash, DSP, and tons of I/O. It’s a relatively new part, so are there any breakout or dev boards for it? Sure thing. [satsha] used a desktop CNC mill to create what is probably the simplest possible breakout board for the STM32F7. There’s not much here — just some parts for power and a few LEDs — but this is all you need to get one of these powerful chips up and running.

It’s cold and dark and you can’t fly RC airplanes in January. It’s not because planes and quadcopters don’t work in the cold (they should work better, but I’d love to see a graph of battery temperature and density altitude), it’s that your hands don’t work in the cold. What’s the solution? Just strap some motorcycle handwarmer thingies onto your transmitter. With a 2200 battery strapped to the back, you’ll get about an hour of runtime for these handwarmers.

The BBC is reporting the latest advancement in Hyperloop technology. Is it a fundamentally different way of digging tunnels that isn’t simply scaling down the size of tunnel boring machines? No. Is it improvements in material science that would allow the seals on a 500-mile-long steel pressure chamber to exist? No. Does this latest advancement mitigate the ‘hillbillies with guns’ problem that would turn every Hyperloop car into a literal bullet screaming towards one of the most spectacular deaths possible? No. The chief executive of the Virgin Hyperloop project has something better in mind. A smartphone app, “that would connect future Hyperloop passengers with other modes of transport on arrival.”

See This Slick RC Strandbeest Zip Around

January 3, 2018 by Donald Papp 8 Comments

Bevel gears used to mount motors vertically.

Theo Jansen’s Strandbeest design is a favorite and for good reason; the gliding gait is mesmerizing and this RC version by [tosjduenfs] is wonderful to behold. Back in 2015 the project first appeared on Thingiverse, and was quietly updated last year with a zip file containing the full assembly details.

All Strandbeest projects — especially steerable ones — are notable because building one is never a matter of simply scaling parts up or down. For one thing, the classic Strandbeest design doesn’t provide any means of steering. Also, while motorizing the system is simple in concept it’s less so in practice; there’s no obvious or convenient spot to actually mount a motor in a Strandbeest. In this project bevel gears are used to mount the motors vertically in a central area, and the left and right sides are driven independently like a tank. A motor driver that accepts RC signals allows the use of an off the shelf RC transmitter and receiver to control the unit. There is a wonderful video of the machine zipping around smoothly, embedded below.

Continue reading “See This Slick RC Strandbeest Zip Around” →

3D Printed Airplane Engine Runs On Air

December 27, 2017 by Bryan Cockfield 13 Comments

One of the most important considerations when flying remote-controlled airplanes is weight. Especially if the airplane has a motor, this has a huge potential impact on weight. For this reason, [gzumwalt] embarked on his own self-imposed challenge to build an engine with the smallest weight and the lowest parts count possible, and came away with a 25-gram, 8-part engine.

The engine is based around a single piston and runs on compressed air. The reduced parts count is a result of using the propeller axle as a key component in the engine itself. There are flat surfaces on the engine end of the axle which allow it to act as a valve and control its own timing. [gzumwalt] notes that this particular engine was more of a thought experiment and might not actually produce enough thrust to run an airplane, but that it certainly will spark up some conversations among RC enthusiasts.

The build is also one of the first designs in what [gzumwalt] hopes will be a series of ever-improving engine designs. Perhaps he should join forces with this other air-powered design that we’ve just recently featured. Who else is working on air-powered planes? Who knew that this was a thing?

Continue reading “3D Printed Airplane Engine Runs On Air” →

Acetone Smoothing Results In Working Motor

November 20, 2017 by Brian Benchoff 20 Comments

Here’s something only ’90s kids will remember. In 1998, the Air Hogs Sky Shark, a free-flying model airplane powered by compressed air was released. This plane featured foam stabilizers, wings, a molded fuselage that served as a reservoir, and a novel engine powered by compressed air. The complete Sky Shark setup included an air pump. All you had to do was plug the plane into the pump, try to break the pressure gauge, and let the plane fly off into a tree or a neighbor’s rooftop. It’s still a relatively interesting mechanism, and although we’re not going to see compressed air drones anytime soon it’s still a cool toy.

Since [Tom Stanton] is working at the intersection of small-scale aeronautics and 3D printing, he thought he would take a swing at building his own 3D printed air motor. This is an interesting challenge — the engine needs to be air-tight, and it needs to produce some sort of usable power. Is a standard printer up to the task? Somewhat surprisingly, yes.

The design of [Tom]’s motor is more or less the same as what is found in the Air Hogs motor from twenty years ago. A piston is attached to a crank, which is attached to a flywheel, in this case a propeller. Above the cylinder, a ball valve keeps the air from rushing in. A spring is mounted to the top of the piston which pushes the ball out of the way, allowing air into the cylinder. At the bottom of the stroke, the ball closes the valve and air escapes out of the bottom of the cylinder. Simple stuff, really, but can it be printed?

Instead of the usual printer [Tom] uses for his builds, he pulled out an old delta slightly modified for higher quality prints. Really, this is just a 0.2 mm nozzle and a few tweaks to the print settings, but the air motor [Tom] designed came out pretty well and was smoothed to a fine finish with acetone.

After assembling the motor, [Tom] hooked it up to a soda bottle serving as a compressed air reservoir. The motor worked, although it’s doubtful a plane powered with this motor would fly for very long. You can check out [Tom]’s video below.

Continue reading “Acetone Smoothing Results In Working Motor” →

3D Printed Hovercraft Takes To The Air

November 6, 2017 by John Baichtal 15 Comments

Instructables user [John_Hagy] and some classmates built an RC hovercraft as their final project in the Robotics Education Lab at NC State University. It’s a foam slab with a Hovership H2204X 2300Kv brushless motor inflating a skirt made out of ripstop nylon. Nylon is great here because it has a low friction coefficient and is nonporous to keep the air in. A second motor propels the craft, with a servo turning the whole motor assembly to steer. The team designed and 3D-printed fan holders which also help channel the air to where it’s supposed to go. Control is via a typical radio-control transmitter and receiver combo.

The project writeup includes a lot of fun detail like previous versions of the hovercraft as well as the research they undertook to learn how to configure the craft — clearly it’s their final paper put on the internet, and well done guys.

Needless to say, we at Hackaday can’t get enough of this sort of thing, as evidenced by this cool-looking hovercraft, this hovercraft made on a budget and this solar-powered ‘craft.

How To Build An Airplane In A Month And A Half

November 1, 2017 by Brian Benchoff 49 Comments

For the last few weeks, RC pilot extraordinaire [Peter Sripol] has been working on his biggest project to date. It’s effectively a manned RC plane, now legally a Part 103 ultralight. Now all that work is finally bearing fruit. [Peter] is flying this plane on some short hops down a grass runway. He’s flying it, and proving that you can build a plane in a basement, in under two months, constructed almost entirely out of insulation foam.

[Peter] has been documenting this build on his YouTube channel, and although the materials for this plane are mostly sourced from either Home Depot or Lowes, the construction is remarkably similar to what you would expect to find in other homebuilt aircraft. This thing has plywood gussets, the foam is wearing a thin layer of fiberglass, and the fasteners are from Aircraft Spruce.

The power system is another matter entirely. The engines (all two of them!) are electric and are designed for very large RC aircraft. These engines suck down power from a massive battery pack in the nose, and the twin throttles are really just linear potentiometers hacked onto servo testers. There’s a surprising amount of very important equipment on this plane that is just what [Peter] had sitting around the workshop.

As far as the legality of this ultralight experiment is concerned, [Peter] is pretty much above-board. This is a Part 103 ultralight, and legally any moron can jump in an ultralight and fly. There are some highly entertaining YouTube videos attesting this fact. However, in one of [Peter]’s livestreams, he flew well after sunset without any strobes on the plane. We’re going to call this a variant of go-fever, technically illegal, and something that could merit a call from the FAA. We’re going to give him a pass on this, though.

This build still isn’t done, though. The pitot tube is held onto the windshield with duct tape. The plane was slightly nose heavy, but shifting the batteries around helped with that. [Peter] is running the motors on 12S batteries, and the prop/motor combo should be run on 14S batteries — $1200 of batteries are on order. The entire plane needs a paint job, but there’s no indication that will ever be done. With all that said, this is a functional manned aircraft built in a basement in less than two months.

With the plane complete and ground tests quickly moving on to flight tests, it’s only fitting to mention [Peter]’s GoFundMe page for a parachute. [Peter] is going to fly this thing anyway, and this is a great way to deflect Internet concern trolls. [Peter]’s just short of the $2600 needed for a parachute, but if the funds received go over that amount by a few hundred, a ballistic parachute will save [Peter] and the plane.