Wing Opens The Skies For Drones With UTM

May 20, 2019 by Maya Posch 7 Comments

Yesterday Alphabet (formerly known as Google) announced that their Wing project is launching delivery services per drone in Finland, specifically in a part of Helsinki. This comes more than a month after starting a similar pilot program in North Canberra, Australia. The drone design Wing has opted for consists not of the traditional quadcopter design, but a hybrid plane/helicopter design, with two big propellers for forward motion, along with a dozen small propellers on the top of the dual body design, presumably to give it maximum range while still allowing the craft to hover.

With a weight of 5 kg and a wingspan of about a meter, Wing’s drones are capable of lifting and carrying a payload of about 1.5 kg. This puts it into a category of drones far beyond of what hobbyists tend to fly on a regular basis, and worse, it involves Beyond Visual Line Of Sight (BVLOS for short) flying, which is frowned upon by the FAA and similar regulatory bodies. What Google/Alphabet figures that can enable them to make this kind of service a commercial reality is called Unmanned aircraft system Traffic Management (UTM).

UTM is essentially complementary to the existing air traffic control systems, allowing drones to integrate into these flows of manned airplanes without endangering either. Over the past years, it’s been part of NASA’s duty to develop the systems and infrastructure that would be required to make UTM a reality. Working together with the FAA and companies such as Amazon and Alphabet, the hope is that before long it’ll be as normal to send a drone into the skies for deliveries and more as it is today to have passenger and cargo planes with human pilots take to the skies.

Battle Tested Current Limiter For Cheap DC Motor Controllers

May 11, 2019 by Jenny List 1 Comment

Running a brushed motor in muddy or dusty environments takes a toll on controllers, with both heavy back EMF and high stall currents. This explains one of the challenge in Europe’s Hacky Racer series, which is decidedly more off-road than America’s Power Racing Series.

In pushing these little electric vehicles to the limits, many builders use brushless Chinese scooter motors since they’re both available and inexpensive. Others take the brushed DC route if they’re lucky enough to score a motor — and then the challenge becomes getting the most performance without burning up your controller. To fix this, [MechanicalCat] has come up with a current limiter for cheap DC motor controllers.

The full write-up is in the included PDF file, and describes the set-up of an Arduino Nano sitting between throttle and controller, and taking feedback from a current sensor. The controller in question is a 4QD Porter 10 so an extra component is a DC-to-DC converter to provide a floating ground for the Arduino. However, there is also the intriguing possibility of the same set-up being used with absurdly cheap Chinese motor controllers. There is also advice on fitting flyback diodes, something which might have saved one controller in the Hackaday pits last year.

It’s yet to be seen what effect this will have on Hacky Racer competitiveness, however its applications go far beyond that field into anywhere a reliable small DC motor drive on the cheap is required. Meanwhile, if you’re unsure where this Hacky Racer stuff came from, you could start here.

Python And Pi Provide Heads Up Display For Your Experimental Airplane

May 10, 2019 by Brian Benchoff 9 Comments

You shouldn’t be looking at screens when you’re driving, but what about a heads-up display? A screen that could put relevant information in your field of vision would be great, even more so if it used a Raspberry Pi. That’s exactly what [John] did, only he did it with an airplane.

First up, the legality of this build. [John]’s plane is registered as experimental, which, provided you know what you’re doing, is pretty close to ‘anything goes’ as you would want in a manned aircraft. [John] has a sufficient number of hours in his log book, and he’s built a Zenith 701.

For hardware, the hard part of this build is constructing a heads-up display. Fortunately, aftermarket HUDs exist, and [John] is using a Kivic projector, a $200 piece of equipment that’s readily available on Amazon. If you need a HUD for your car, there you go. The software is another thing entirely, with the goal of having the software decoupled from the display and data sources. This is somewhat easy to accomplish with a Raspberry Pi; the display is actually just some minimal text-based blocky graphics built in PyGame. This build is also decoupled from the data sources by building this as a user interface for Stratux, an independent Raspberry Pi-based ADS-B receiver for pilots.

There are several views available with this HUD, with the AHRS + ADS-B providing information on the aircraft’s attitude and altitude, along with a few indicators of the nearest planes. The traffic view expands on the ADS-B data, showing the nearest eight or so aircraft in the air, with a range, bearing, and difference in altitude. There’s a diagnostic window, and since [John]’s plane is a backcountry STOL thingamado that can hover in a strong wind, there’s also a digital version of a norden bombsight. It’s for dropping bags of flour onto a grass strip. You can check out [John]’s entire AirVenture presentation of the build below, with all the code available here.

Continue reading “Python And Pi Provide Heads Up Display For Your Experimental Airplane” →

Remanufacturing A Rotary Airplane Engine

April 13, 2019 by Jenny List 66 Comments

If someone tells you they have seen a rotary engine, the chances are that you will immediately think of a Wankel engine, as you might find in some of the more exotic Mazda sports cars. But there is another rotary engine that has a prior claim to the name, and it can be found as the power unit for many early-twentieth-century aircraft. In these rotary engines the cylinders are arranged radially around a stationary crankshaft, and it is the engine itself that rotates. They have the advantage of extreme simplicity, smooth power, and a low parts count, at the expense of total loss lubrication, a relatively large rotating mass, and some difficulty in controlling their power. These rotary engines were largely obsolete by the 1920s, but recent upsurge of interest in WW1-era aircraft has led to the creation of a small demand for them. New Zealand based Classic Aero Machining Service have stepped in to fill that gap and are remanufacturing the Gnome radial engine, the most numerous design of that era.

For anyone with an interest in internal combustion engines, the Gnome is a fascinating study. It’s a nine-cylinder design that runs a four-stroke Otto cycle, but instead of the two or more valves you might be familiar with from your motor vehicle it has only a single valve. The so-called Monosoupape design uses its valve for both fuel and exhaust, opening it on the inlet stroke as well as the exhaust stroke. The simplicity of a single valve and no carburetor is thus offset by a difficulty in varying its power , so rotary engines would frequently reduce the number of firing cylinders in lieu of throttling back.

The CAMS Gnome is a faithful copy of the original, but with modern metallurgy and the addition of an electronic ignition system. The original castor oil is still used — it seems classic aviation buffs like the smell — but becuase it is notorious for leaving sticky deposits in the engine they are evaluating modern alternatives. They have some technical details on their website, and there’s a good chance you my hear one of their engines one day at an air show near you.

Continue reading “Remanufacturing A Rotary Airplane Engine” →

Goodyear Aero Thinks Flying Cars Are A Thing

March 29, 2019 by Al Williams 70 Comments

The 2019 Geneva International Motor Show has a number of “concept” vehicles. These are vehicles that usually include some cool feature that isn’t really practical — at least today. For example, in the past, concept cars have had adjustable color interior lighting, plug-in hybrid engines, and power windows — all things that would eventually become commonly available. However, today’s advances in computer-generated graphics have meant you can show things you can’t begin to build. Case in point: Goodyear has a video touting the Aero — a solid car tire that doubles as a propeller for your garden variety flying car.

To us, the thing looks more like a science fiction movie trailer than anything remotely practical. Four relatively small wheels with no central hub can flip and provide enough lift to propel a sizeable vehicle skyward. Even more interesting, is to transition modes from ground to flight, the vehicle balances on two wheels while using only two as propellers to generate lift.

Continue reading “Goodyear Aero Thinks Flying Cars Are A Thing” →

Retired Rideshare Scooter Skips The Reverse Engineering To Ride Again

March 19, 2019 by Donald Papp 7 Comments

[Adam Zeloof] (legally) obtained a retired electric scooter and documented how it worked and how he got it working again. The scooter had a past life as a pay-to-ride electric vehicle and “$1 TO START” is still visible on the grip tape. It could be paid for and unlocked with a smartphone app, but [Adam] wasn’t interested in doing that just to ride his new scooter.

His report includes lots of teardown photos, as well as a rundown of how the whole thing works. Most of the important parts are in the steering column and handlebars. These house the battery, electronic speed controller (ESC), and charging circuitry. The green box attached to the front houses a board that [Adam] determined runs Android and is responsible for network connectivity over the cellular network.

To get the scooter running again, [Adam] and his brother [Sam] considered reverse-engineering the communications between the network box and the scooter’s controller, but in the end opted to simply replace the necessary parts with ones under their direct control. One ESC, charger, and cheap battery monitor later the scooter had all it needed to ride again. With parts for a wide variety of electric scooters readily available online, there was really no need to reverse-engineer anything.

Ridesharing scooter startups are busy working out engineering and security questions like how best to turn electric scooters into a) IoT-connected devices, and b) a viable business plan. Hardware gets revised, and as [Adam] shows, retired units can be pressed into private service with just a little work.

The motors in these things are housed within the wheels, and have frankly outstanding price-to-torque ratios. We’ve seen them mated to open-source controllers and explored for use in robotics.

A Big, Mean, Inflated Machine

March 1, 2019 by Lewin Day 21 Comments

A Jeep is fun offroad, a motorcycle perhaps even more so. Diehard renegades go even further and get about in Unimogs and on snowmobiles. [amazingdiyprojects] might just have topped them all however, with his latest project – the astonishing Inflatable Car.

Despite the name, it’s a vehicle that defies clear definition. Consisting of a lightweight aluminium frame and exposed seat, the construction is almost 100% hacked. PVC fabric is used with advanced adhesive tapes to create inflatable wheels that are 2 meters in diameter. Vacuum cleaners are used to inflate the massive tyres, with custom 3D printed valves to ensure even inflation. Drive is courtesy of four handheld concrete mixers, repurposed for their torquey motors and robust geartrains. Even the user interface is a triumph of found parts – consisting of former cordless drills, used for their PWM hardware and covered in extra switches.

Looking like a moon lander from a strange 1950s version of the future, the machine is impressively nimble for its size. Episode 1 starts with a single wheel hooked up to the inflation gear and a single drive motor. Just a few short months later, episode 7 has the prototype machine crawling out from the confines of the back garden and out into the street. The machine is already impressively fast and capable, and we can’t wait to see what happens next.

It’s a build that is truly impressive in its scale, though we’ve come to expect no less from [amazingdiyprojects]. Video after the break.

Continue reading “A Big, Mean, Inflated Machine” →