The Politics Of Supersonic Flight: The Concord(e)

January 25, 2021 by Jenny List 29 Comments

Every nation has icons of national pride: a sports star, a space mission, or a piece of architecture. Usually they encapsulate a country’s spirit, so citizens can look up from their dreary lives and say “Now there‘s something I can take pride in!” Concorde, the supersonic airliner beloved by the late 20th century elite for their Atlantic crossings, was a genuine bona-fide British engineering icon.

But this icon is unique as symbols of national pride go, because we share it with the French. For every British Airways Concorde that plied the Atlantic from London, there was another doing the same from Paris, and for every British designed or built Concorde component there was another with a French pedigree. This unexpected international collaboration gave us the world’s most successful supersonic airliner, and given the political manoeuverings that surrounded its gestation, the fact that it made it to the skies at all is something of a minor miracle. Continue reading “The Politics Of Supersonic Flight: The Concord(e)” →

An Alternator Powered Electric Bicycle Gives Rotor Magnetic Field Insight

January 24, 2021 by Jenny List 63 Comments

For anyone involved in the construction of small electric vehicles it has become a matter of great interest that a cheap high-power electric motor can be made from a humble car alternator. It’s a conversion made possible by the advent of affordable three-phase motor controllers, and it’s well showcased by [austiwawa]’s electric bicycle build video (embedded below).

The bike itself is a straightforward conversion in which the motor powers the rear wheel via an extra sprocket. He tried a centrifugal clutch with limited success, but removed it for the final version. Where the interest lies in this build is in his examination of Hall effect sensor placement.

Most alternator conversions work without sensors, though for better control it’s worth adding these magnetic sensors to allow the controller to more directly sense the rotation. He initially placed them at the top of the stator coils and found them to be ineffectual, with the big discovery coming when he looked at the rotor. The electromagnet in the rotor on a car alternator has triangular poles with the field concentrated in the centre of the stator, thus a move of the sensors to half way down the stator solved the problem. Something to note, for anyone converting an alternator.

Should you wish to give it a try, a year ago we published a primer on turning car parts into motors.

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Multi-Channel Battery Monitor Aces First Sea Trial

January 20, 2021 by Tom Nardi 4 Comments

A little over a a year ago, we covered an impressive battery monitor that [Timo Birnschein] was designing for his boat. With dedicated batteries for starting the engines, cranking over the generator, and providing power to lights and other amenities, the device had to keep tabs on several banks of cells to make sure no onboard systems were dipping into the danger zone. While it was still a work in progress, it seemed things were progressing along quickly.

But we know how it is. Sometimes a project unexpectedly goes from having your full attention to winning an all-expense-paid trip to the back burner. In this case, [Timo] only recently put the necessary finishing touches on his monitor and got it installed on the boat. Recent log entries on the project’s Hackaday.io page detail some of the changes made since the last time we checked in, and describe the successful first test of the system on the water.

Certainly the biggest issue that was preventing [Timo] from actually using the monitor previously was the lack of an enclosure and mounting system for it. He’s now addressed those points with his 3D printer, and in the write-up provides a few tips on shipboard ergonomics when it comes to mounting a display you’ll need to see from different angles.

The printed enclosure also allowed for the addition of some niceties like an integrated 7805 voltage regulator to provide a solid 5 V to the electronics, as well as a loud piezo beeper that will alert him to problems even when he can’t see the screen.

Under the hood he’s also made some notable software improvements. With the help of a newer and faster TFT display library, he’s created a more modern user interface complete with a color coded rolling graph to show voltages changes over time. There’s still a good chunk of screen real estate available, so he’s currently brainstorming other visualizations or functions to implement. The software isn’t using the onboard NRF24 radio yet, though with code space quickly running out on the Arduino Nano, there’s some concern about getting it implemented.

As we said the first time we covered this project, you don’t need to have a boat to learn a little something from the work [Timo] has put into his monitoring system. Whether you’re tracking battery voltages or temperatures reported by your BLE thermometers, a centralized dashboard that can collect and visualize that data is a handy thing to have.

Party Canoe Lights Up The Water

January 7, 2021 by Lewin Day 26 Comments

Generally, any activity out on the water is more dangerous when done at night. Hazards are less visible, and it can be easy to get into trouble. [Xyla Foxlin]’s party canoe can’t help with that, but it does look the business after dark.

The canoe is made out of fiberglass, directly formed onto an existing canoe to make getting the shape right easy. It was formed in two halves, with special care taken to make the final result as clear as possible. Obviously, fiberglass is never going to be perfectly transparent, but [Xyla] does a great job of getting a nice translucent frosted look. The final effect means that it’s the perfect canoe to stuff full of addressable LEDs. A string of WS2812Bs, hooked up to an Arduino, make for an appealing lightshow when boating at night.

The diffusive nature of the fiberglass really makes the difference here. We’ve talked about the topic before – it’s the key to making your glowy project really pop. Video after the break.

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AI On The Highway

January 5, 2021 by Chris Lott 13 Comments

A couple of announcements caught our attention last week regarding AI-controlled cars. South Korea’s Kakao Mobility and local startup Autonomous A2G launched a limited self-driving taxi service in Sejong City this month, made possible by enabling legislation passed in May. For now, the service is restricted to government employees, and the AI driver will be backed-up by an engineer who is there to monitor the systems and take over in an emergency. The companies plan to expand the fleet and service areas this year, although no details are given.

Another announcement comes from the Ministry of Land, Infrastructure and Transport about the on-going successes of the semi-autonomous truck platooning program. This is a collaboration between the Korean Expressway Corporation, Kookmin University in Seoul, and Hyundai Motors. Previously restricted to a designated test road called the Yeoju Smart Highway, the program is now being tested on public roads at speeds up to 70 kph. This year the program will expand to platoons of 4 trucks running at 90 kph. We’ve always thought that long-haul trucking and freight industries would be an early adaptor AI technologies, and one which AI could offer significant benefits.

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ABS Mercedes Rims Push The Limits Of 3D Printing

January 3, 2021 by Danie Conradie 49 Comments

While we’re big believers in 3D printing here at Hackaday, there’s no denying that some things just aren’t meant to be printed. For example, most of us would agree that it’s not the first choice for making rims for a passenger car. We imagine that [Jón Schone] from Proper Printing probably feels the same way, but that didn’t stop him from trying to do it anyway.

A couple of months ago [Jón] got a test subject in the form of an older Mercedes with 19-inch rims. The first two challenges are bed size and warping, so he modified a Creality CR10 S5 with a heated chamber capable of reaching 70 °C to reduce warping with the ABS filament he intended to use. Another challenge is the amount of filament required for the print, especially since [Jón] wasn’t keen on babysitting the machine to replace the spool every so often. His attempt at building a filament joiner ultimately didn’t work out, so in the end he simply sourced the filament in bulk size rolls.

Bolts hold the two halves of the rim together.

Eventually [Jón] managed to print a complete rim in two halves, bolted together around its circumference. Unfortunately, even with the heated chamber, the parts still warped all around the edges. This left a gap at the seam, but to fit a tubeless tire, the rim had to be airtight. So the entire inside surface was painted to close any small gaps, and the larger gaps were filled with sealant.

In the end it was still unable to hold pressure with a tire mounted, so it was test fitted to the car just to see if it would carry the weight. This test also failed, splitting on the thinnest part of the rim. [Jón] has headed back to the drawing board to try again in 2021. We probably would have moved on by now, but you have to admire his tenacity. We hope to see success in the new year.

Printing large parts brings its own set of challenges, but if you stick to good old PLA it’s not too difficult. [Ivan Miranda] has made a name for himself with massive 3D printed projects like a ride-able tank, and also built a supersized 3D printer for future projects.

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Build Your Own Custom Elevator

December 28, 2020 by Bryan Cockfield 67 Comments

There are a lot of things in our everyday life that are holdovers from an earlier time that we continue to use simply because of inertia even if they don’t make a lot of sense in modern times. Examples include a 60 Hz power grid, the spacing between railroad tracks, and of course the self-contained attic ladder which is made to fit in between standard spaced ceiling joists. It’s not wide enough to get big or heavy stuff into an attic, and building standards won’t change just for this one inconvenience, so if you want to turn that space into something more usable you’re going to need to build a custom elevator.

This attic elevator comes to us from [Brian] who recently moved into a home with about half the square footage as his previous home, but still needed to hold all of his stuff. That means clever ways of using the available space. For the elevator he constructed a platform out of 2x lumber held together with bolts and steel supports. The carriage runs up and down on a track made out 1 5/8″ super strut and is hoisted by a winch motor rated for 550 pounds, which is more than enough to hoist up most household items including a large toolbox.

The only thing that we would have liked to have seen in the video is how the opening was made. Presumably this would have involved cutting into a ceiling joist to make the opening wider than the standard attic ladder, and care would have needed to be taken to ensure the ceiling/floor wasn’t weakened. Either way, this is a great solution to a common problem, and could perhaps be made to work on more than two levels with a custom controller. Continue reading “Build Your Own Custom Elevator” →