3D Printing A Full Scale Fiberglass Speedboat

January 30, 2021 by Al Williams 15 Comments

It’s an age-old problem. You draw up a nice 6.5-meter long motorboat and then discover the shape won’t allow for a fiberglass mold. What do you do? If you’re [Moi], you grab a few Kuka robots and 3D print it using thermoplastic with embedded glass fibers. A UV light cures the plastic and you wind up with printed fiberglass. That’s the story behind the MAMBO, a 3D printed powerboat.

Despite the color, the fiberglass isn’t blue out of the gate — the boat is painted. Still, it looks nice with lines inspired by [Sonny Levi]’s Arcidiavolo design from 1973. MAMBO stands for Motor Additive Manufacturing BOat. It has a dry weight of about 800 kg and is fitted with a cork floor, white leather seats, and an engine. We presume none of those things were 3D printed.

Although it wasn’t fiberglass, we’ve seen a 3D printed boat before. In particular, the University of Maine’s giant 22,000 square foot printer cranked one out. We’ve also seen boats printed in standard PLA filament, which then had fiberglass cloth and resin applied after printing. True that one was only RC, but there’s no reason the concept couldn’t be scaled up if you had the patience.

Scrappy: Drag Racing Bush Plane

January 30, 2021 by Danie Conradie 19 Comments

We like to feature hacks that are affordable and accessible to the average person, but from time to time it’s fun to dream about the projects we’ll tackle when we’re all grown up and stinking rich. [Mike Patey] appears to fall rather comfortably in the latter category, but thankfully he hasn’t lost his “excited kid with big plans” spirit. A talented and experienced experimental aircraft builder, he’s currently working on Scrappy, a small bush plane built to be a short take-off and landing drag racer.

Scrappy started life as a Carbon Cub, a modernized kit version of the venerable Piper Super Cub. The only thing left of the original plane is a part of the fuselage frame, with almost everything else being custom. The engine is a 780 cubic inch (13 liter) horizontally opposed 8-cylinder, scavenged from one of [Mike]’s racing planes, and fitting it required extensive structural changes to the fuselage. The paddle-like propeller was intended for an airboat, and is designed for high thrust at low speeds. The skin of the aircraft is all carbon fiber, and the suspension almost looks like it’s borrowed from an off-road racing truck. [Mike] also added (and test fired) a ballistic recovery parachute. The cockpit instruments are also over-the-top for an aircraft like this, with seven Garmin multi-function displays.

Scrappy is still missing its wings, which will also be heavily modified. From the oil-cooling system to the door latch and gust-lock for the stick, everything was designed and made by [Mike]. We’re enjoying the in-depth build videos that show how he tackles all the little challenges that pop-up in such an ambitious project.

[Mike] made a name for himself with his previous monster bush plane Draco, which was sadly destroyed during an ill-considered take-off last year. Fortunately nobody was harmed in the incident, and Draco became a part donor for Scrappy. If budget planes are more your style, check out [Peter Sripol]’s latest electric microlight.

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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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