Hackaday Belgrade: Sophi Kravitz’s Blimp Army

August 2, 2018 by 12 Comments

Building things that fly is hard. The constraints on small, battery powered, radio-operated gear already presents a challenge, but adding weight, balance, and aerodynamic constraints takes it to a whole new level. Sophi Kravitz rises to the occasion and discusses each challenge of building a blimp from start to finish in her presentation at the 2018 Hackaday Belgrade conference.

One of the pleasures of writing for Hackaday comes through the incredible array of talent and experience to be found among our colleagues. We all do our own work, but one is humbled by that which flows from the benches of those one works alongside. Just such a project is the Remote Control Mini Blimp from our colleague Sophi Kravitz. It’s a game involving an obstacle course and a set of remote-controlled blimps. The challenges in such an endeavour have been pushing the limits of what is possible with off-the-shelf components. Continue reading “Hackaday Belgrade: Sophi Kravitz’s Blimp Army” →

Quadcopter Hardware Gets Classic Lake Bed Test

August 1, 2018 by 6 Comments

You’d be hard pressed to find an aircraft that wasn’t designed and tested without extensive use of simulation. Whether it’s the classic approach of using a scale model in a wind tunnel or more modern techniques such as computational fluid dynamics, a lot of testing happens before any actual hardware gets bolted together. But at some point the real deal needs to get a shakedown flight, and historically a favorite testing ground has been the massive dry lake beds in the Western United States. The weather is always clear, the ground is smooth, and there’s nobody for miles around.

Thanks to [James] and [Tyler] at Propwashed, that same classic lake bed approach to real-world testing has now been brought to the world of high performance quadcopter gear. By mounting a computer controlled thrust stand to the back of their pickup truck and driving through the El Mirage dry lake bed in the Mojave Desert, they were able to conduct realistic tests on how different propellers operate during flight. The data collected provides an interesting illustration of the inverse relationship airspeed has with generated thrust, but also shows that not all props are created equal.

The first post in the series goes over their testing set-up and overall procedure. On a tower in the truck’s bed a EFAW 2407 2500kV motor was mounted on a Series 1520 thrust stand by RCBenchmark. This stand connects to the computer and offers a scripted environment which can be used to not only control the motor but monitor variables like power consumption, RPM, and of course thrust. While there was some thought given to powering the rig from the truck’s electrical system, in the end they used Turnigy 6000mAh 4S battery packs to keep things simple.

A script was written for the thrust stand which would ramp the throttle from 0% up to 70% over 30 seconds, and then hold it at that level for 5 seconds. This script was run when the truck was at a standstill, and then repeated with the truck travelling at increasingly faster speeds up to 90 MPH. This procedure was repeated for each of the 15 props tested, and the resulting data graphed to compare how they performed.

The end result was that lower pitch props with fewer blades seemed to be the best overall performers. This isn’t a huge surprise given what the community has found through trial and error, but it’s always good to have hard data to back up anecdotal findings. There were however a few standout props which performed better at high speeds than others, which might be worth looking into if you’re really trying to push the envelope in terms of airspeed.

As quadcopters (or “drones”, if you must) have exploded in popularity, we’re starting to see more and more research and experimentation done with RC hardware. From a detailed electrical analysis of hobby motors to quantifying the latency of different transmitters.

Casting Tour-De-Force Results In Swashplate For Scale Helicopter

July 5, 2018 by 21 Comments

While quadcopters seem to attract all the attention of the moment, spare some love for the rotary-wing aircraft that started it all: the helicopter. Quads may abstract away most of the aerodynamic problems faced by other rotorcraft systems through using software, but the helicopter has to solve those problems mechanically. And they are non-trivial problems, since the pitch of the rotors blades has to be controlled while the whole rotor disk is tilted relative to its axis.

The device that makes this possible is the swashplate, and its engineering is not for the faint of heart. And yet [MonkeyMonkeey] chose not only to build a swashplate from scratch for a high school project, but since the parts were to be cast from aluminum, he had to teach himself the art of metal casting from the ground up. That includes building at least three separate furnaces, one of which was an electric arc furnace based on an arc welder with carbon fiber rods for electrodes (spoiler alert: bad choice). The learning curves were plentiful and steep, including getting the right sand mix for mold making and metallurgy by trial and error.

With some machining help from his school, [MonkeyMonkeey] finally came up with a good design, and we can’t wait to see what the rest of the ‘copter looks like. As he gets there, we’d say he might want to take a look at this series of videos explaining the physics of helicopter flight, but we suspect he’s well-informed on that topic already.

[via r/DIY]

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Hackaday Links: Benchoff Rants On Flying Cars

June 10, 2018 by 52 Comments

It’s time for Computex, and that means [Linus] has dropped something. I don’t know what, but he’s dropped something. It’s a meme or something at this point. What were the highlights? Asus announced Project Precog, a laptop with two screens. Yes, a touchscreen keyboard. It’s the 2018 version of the IBM Transnote or whatever that Microsoft thing was called. Why is it called Project Precog? Because AI or whatever. Unimaginative marketing is terrible. Intel is going to launch a 28-core CPU, and AMD is introducing a 32-core CPU. Awesome, core wars. And here’s RGB RAM because stuffing a case full of cold cathode lighting is sooo early-2000s.

Need a reverse engineering challenge? Here’s something from American Science and Surplus. It’s a 48 x 12 LED matrix, loaded up with driver ICs and power regulators. $20 a piece, so stock up and save.

Finally, the main event. The biggest story in aviation this week is that a media embargo has lifted on the Kitty Hawk Flyer. Kitty Hawk is a startup funded by Larry Page, CEO’d by Sebastian Thrun, and has received $6.5 M in funding. The Flyer, a one-man decacopter, was announced to the world through CNN Money and Casey Neistat. It should be noted that in the entire media landscape, these are the two outlets most ignorant of aviation: CNN needs no explanation, and Neistat flies quadcopters through the Hudson River Corridor at 1000 feet AGL. Additionally, Kitty Hawk is not exhibiting at AirVenture next month, which leads me to believe Kitty Hawk is trying to stay out of the aviation industry or simply doesn’t want knowledgeable people asking them questions. But I digress.

The Kitty Hawk Flyer is being promoted by the company as “a personal flying vehicle… to make flying part of everyday life” and a machine that will give you, “a world free from traffic”. It is being billed by CNN and Neistat as ‘a flying car’. Kitty Hawk is just fine with allowing the media to call it as such. Additionally, Sebastian Thrun is making claims about the Flyer that are disingenuous at best, outright illegal at worst, and should draw the ire of any investors.

In the CNN Money piece, Thrun claims the Flyer is capable of traveling at 100 miles per hour, which would be illegal. The Flier is certified as a Part 103 Ultralight, and under that regulation the Flyer “is not capable of more than 55 knots calibrated airspeed at full power in level flight.” The Flyer may also be overweight. The first version of the Flyer was basically a decacopter with a seat, and weighed in at 220 pounds. Part 103 regulations have a limit of 254 pounds, and it’s entirely possible there are more than 34 pounds of chassis and fiberglass on the latest version. I should also mention the safety training, while not required for a Part 103 ultralight, is insufficient: Casey Neistat’s underwater egress training was done in a Chuck E. Cheese-style ball pit. You can breathe in a ball pit, you can’t breathe underwater.

But legality aside, a Part 103 ‘flying car’ is just about the dumbest idea ever. You can’t use it to commute, and you’re welcome to call your local FSDO to confirm that. You’re not going to fly it in New York City or San Francisco because there are airports in the way. At best, this is a ‘flying ATV’ that you would take out on your farm; a toy for rich people. At worst, it’s the latest example of the Silicon Valley philosophy of ‘ignore laws and break things’.

“Watch Dogs” Inspired Hacking Drone Takes Flight

May 27, 2018 by 19 Comments

They say that life imitates art, which in modern parlance basically means if you see something cool in a video game, movie or TV show, you might be inclined to try and build your own version. Naturally, such things generally come in the form of simple props, perhaps with the occasional embedded LED or noise making circuit. It’s not as if you can really build a phaser from Star Trek or a phone booth that’s bigger on the inside.

But after seeing the hacking quadcopter featured in the video game Watch Dogs 2, [Glytch] was inspired to start work on a real-world version. It doesn’t look much like the drone from the game, but that was never the point. The idea was to see how practical a small flying penetration testing platform is with current technology, and judging by the final build, we’d say he got his answer.

All the flight electronics are off the shelf quadcopter gear. It’s running on a Betaflight OMNIBUS F4 Pro V2 Flight controller with an M8N GPS mounted in the front and controlling the 2006 2400KV motors with a DYS F20A ESC. Interestingly [Glytch] is experimenting with using LG HG2 lithium-ion cells to power the quad rather than the more traditional lithium-polymer pack, though he does mention there are some issues with the voltage curve between the two battery technologies.

But the real star of the show is the payload: a Hak5 Pineapple Nano. As the Pineapple provides a turn-key penetration testing platform on its own, [Glytch] just needed a way to safely carry it and keep it powered. The custom frame keeps it snug, and the 5 Volt Battery Eliminator Circuit (BEC) on the DYS F20A ESC combined with a female USB port allows powering the Pineapple without having to make any hardware modifications.

We’ve seen quadcopters with digital weaponry before, though not nearly as many as you might think. But as even the toy grade quadcopters become increasingly capable, we imagine the airborne hacking revolution isn’t far away.

Continue reading ““Watch Dogs” Inspired Hacking Drone Takes Flight” →

3D Drone Video

April 21, 2018 by 10 Comments

If you enjoy flying quadcopters, it is a good bet that you’ll have a drone with a camera. It used to be enough to record a video for later viewing, but these days you really want to see a live stream. The really cool setups have goggles so you can feel like you are actually in the cockpit. [Andi2345] decided to go one step further and build a drone that streams 3D video. You can see a video of the system, below.

Outdoors, there’s probably not a lot of advantage to having a 3D view, but it ought to be great for a small indoor drone. The problem is, of course, a small drone doesn’t have a lot of capacity for two cameras. The final product uses two cameras kept in sync with a sync separator IC and a microcontroller, while an analog switch intersperses the frames.

On the viewing side, a USB frame grabber and a Raspberry Pi splits the images again. At first, the system used an LCD screen married with a Google Cardboard-style goggle, but eventually, this became a custom Android application.

Continue reading “3D Drone Video” →

Got A Burning Idea For An EMF Camp Presentation? Now’s Your Chance!

April 21, 2018 by 8 Comments

Sometimes the world of tech conference presentations can seem impossibly opaque, a place in which there appears to be an untouchable upper echelon of the same speakers who pop up at conference after conference. Mere mortals can never aspire to join them and are destined to forever lurk in the shadows, their killer talk undelivered.

Thankfully, our community is not like that. There is a rich tradition of events having open calls for participation, and the latest we’d like to bring to your attention comes from the British EMF Camp, to be held at the end of August. EMF, (standing for ElectroMagnetic Field) is a 3-day festival that bills itself as “for those with an inquisitive mind or an interest in making things“. In their call for participation, they are seeking installations and performances as well as talks and workshops, and it’s worth saying given the very quick uptake of their early ticket sales, that a couple of tickets will be reserved for purchase by each person with proposals that are accepted.

EMF Camp like other hacker camps is an extraordinary coming together of people from all conceivable backgrounds and interest groups to share a field for three days. It doesn’t matter how experienced you are, what the subject is that you would like to present, or what installation or workshop you would like to bring, there will be a section of the EMF audience who would be very interested to see it. They list a few previous topics, from genetic modification to electronics, blacksmithing to high-energy physics, reverse engineering to lock picking, computer security to crocheting, and quadcopters to brewing. Assuming that certain submissions are accepted, you may also see a Hackaday scribe delivering a talk.

While you’re thinking of what to submit for 2018, whet your appetite with a look at the goings-on from EMF 2016.

Image: Nottingham Hackspace [CC BY-SA 2.0].