Hackaday Links: August 27, 2017

Hulk Hands! Who remembers Hulk Hands? These were a toy originally released for the 2003 Hulk movie and were basically large foam clenched fists you could wear. Hulk Hands have been consistently been re-released for various Marvel films, but now there’s something better: it’s the stupidest tool ever. Two guys thought it would be fun and not dangerous at all to create cast iron Hulk Hands and use them as demolition and renovation equipment. This is being sold as a tool comparable to a sledgehammer or a wrecking bar.

New Pogs! We’re up to 0x0C. Is your collection complete?

[Peter] is building an airplane out of foam in his basement. He’s also doing it as a five or six-part series on his YouTube channel. Part two is now up. This update covers the tail surfaces, weighing and balancing the fuselage, and a general Q&A with YouTube comments.  Yes, [Peter] still has a GoFundMe up for a parachute, and it’s already about half funded. With any luck, he’ll have the $2600 for a parachute before he builds the rest of the plane. Another option is a ballistic parachute system — a parachute for the whole plane, like a Cirrus. That would be a bit more than $4000, so we’ll see how far the GoFundMe goes.

Hey, remember the Nvidia Jetson TX1? It’s a miniATX motherboard running a fast ARM core with a GPU housing 256 CUDA cores. It’s cool, and the new version — the TX2 — is designed for ‘machine learning at the edge’. They’re on sale now, for only $199.

Primitive Technology has another video out. This time, he’s improving his bow string blower into something that kinda, sorta resembles a modern forge. This time, the experiment was a success when it comes to pottery — he’s now able to fire clay at a much higher temperature, bringing him reasonably close to modern ceramics. At least, as close as you can get starting with the technology of a pointed stick. The experiment was marginally successful when it came to creating iron. He’s using iron-bearing bacteria (!) for his source of ore and was able to smelt millimeter-sized pellets of iron. This guy needs a source of copper or tin. Zinc is also surprisingly possible given his new found capabilities for ceramics.

Building An Ultralight Out Of Foam In A Basement

[Peter Sripol] is something of a legend in the DIY RC aircraft crowd. He’s friends with Flite Test, and there he built an enormous RC cargo plane that could easily carry a small child aloft. Now, [Peter] is aiming a bit higher. He’s building an ultralight — a manned ultralight — in his basement. It’s made out of insulation foam.

Yes, this ultralight is constructed out of insulation foam, but you can think of that as just a skin. The real structure here comes from a wooden frame that will be fiberglassed. The design of this aircraft is an electric, twin-engine biplane. The relevant calculations have already been done, and [Peter] is already flying an RC scale model of this craft. So far, everything is not as sketchy as it could be.

As with any, ‘guy builds an airplane in his basement’ story, there must be a significant amount of time dedicated to the legality, practicality, and engineering of said plane. First off, the legality. [Peter] is actually building an ultralight under Part 103. The certifications for a Part 103 ultralight are much more lenient than the next step up in FAA-certified aircraft, a light sport or experimental aircraft. An ultralight is not required to have an airworthiness certification, and pilots of ultralights are not required to pass any tests of aeronautical knowledge or hold a medical certificate. Yes, legally, any moron can jump in an ultralight and fly. Think about that the next time someone brings up the Part 107 ‘drone’ certification.

Next, the practicality and engineering. [Peter]’s plane can weigh a maximum of 254 pounds, and should not be capable of more than 55 knots in full power level flight, while having a stall speed that does not exceed 24 knots. This is slow for a Cessna, but just about right for the gigantic remote-controlled planes [Peter] has already built.  A few years ago, [Peter] built a gigantic remote-controlled cargo plane out of what is basically foam board and a few aluminum tubes. The construction of [Peter]’s ultralight will be a highly refined version of this. He’s using foam insulation sheets for the body of the fuselage, reinforced with plywood and poplar struts. This foam and wood build will be wrapped with carbon fiber and fiberglass sheet, epoxied, and hopefully painted with flames on the side.

The use of poplar is a bit curious for an ultralight aircraft. For the last hundred years, the default wood for aircraft has been either spruce or douglas fir. The reason for this choice is the strength to weight ratio; spruce and douglas fir have the highest strength to weight ratio of any other wood. Poplar, however, is ultimately stronger and available at his local home improvement store, even though it does weigh a bit more. If [Peter] can keep the weight down in other areas, poplar is an excellent choice due to cost and availability. The video (below) is unclear, but we can only hope [Peter] has read up on the strength of aircraft frames and the orientation of the grain of each structural member.

This is the first video in what will be an amazing build series, and [Peter] hopes to get this thing up in the air by September. If you’re concerned about [Peter]’s safety, he’s also put up a GoFundMe page for a parachute. [Peter]’s going to fly this thing if you complain or concern troll or not, so donate a dollar for the parachute if you’re that concerned.

Continue reading “Building An Ultralight Out Of Foam In A Basement”

Hackaday Prize Entry: Modular Instrumentation For Aircraft

Parts, tools, and components for aviation and aerospace are sold in ‘Aviation Monetary Units’ (AMU). Right now, the conversion factor from USD to AMU is about 1000 to 1. This stuff is expensive, but there is a small portion of the flying community that prides itself on not breaking the bank every time something needs to be replaced. Theses are often the microlight, ultralight, and experimental aircraft enthusiasts. Steam gauges are becoming obsolete and expensive to repair, and you’re not going to throw a 15 AMU Garmin G500 in an ultralight that only costs 10 AMU.

To solve this problem, [Rene] is turning to sensors, displays, and microcontrollers that are cheap and readily available to build modular aviation instruments.

As with all aviation gear, the first question that springs to mind is, ‘what will the FAA think about this?’. [Rene] is in South Africa, so the answer is, ‘nothing’. If a few American pilots decide to build one of these, that’ll fly too; these are instruments designed for non-type-certified aircraft. That’s not to say there are no rules for what goes into these aircraft, but the paperwork is much easier.

Right now, the design goals for [Rene]’s instruments is under 0.1 AMU per module, robust, RF shielded, with engine monitoring, fuel management, heading, air and ground speed, altitude, attitude, and all the other gauges that make flying easy. He’s using a CAN bus for all of these modules, and in the process slowly dragging the state of the art of ultralight aviation into the 1990s. It’s fantastic work, and we can’t wait to see some of these modules in the air.