A man riding a buggy pulled by a wooden contraption

Maakrapu Is A Buggy Drawn By A Five-Legged Beast

The steampunk aesthetic can take on many forms, and while pipes, valves, and boilers can look great, having complicated machinery with lots of moving parts really makes your project shine. A team of steampunk enthusiasts over at Tampere Hacklab did this by building a vehicle named Maakrapu. It’s a two-wheeled buggy that looks like it’s being pulled forward by some kind of five-legged creature. The extremely smooth motion of its legs conjures up images of lobsters or crabs (“Maakrapu” means “land crab” in Finnish), and is also reminiscent of Theo Jansen’s Strandbeesten.

The wooden legs are linked together with a metal crankshaft, which was welded together from plasma-cut parts. A steering wheel is included to orient the legs in the direction of travel, although the actual steering of the vehicle is done through differential braking. An earlier version had no propulsion and was meant for downhill riding only, but this latest model comes with an electric motor and a battery, making it actually somewhat useful as an urban runabout.

The video embedded below shows the design of the Maakrapu as well as a long drive from the center of Tampere back to the Hacklab. If you like vehicles with lots of little moving legs like this, check out the Strandbeest Bicycle. For a more literal “steam”-punk experience, try this steam-powered bike.

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Supercapacitor E-Bike With DIY Motor

Supercapacitor technology often looks like a revolutionary energy storage technology on the surface, but the actual performance numbers can be rather uninspiring. However, for rapid and repeated charge and discharge cycles, supercaps are hard to beat. [Tom Stanton] wanted to see if supercaps have any practical use on e-bikes, and built a DIY electric motor in the process.

One of the problems with supercaps is the rapid voltage drop during discharge compared to batteries, which can limit the amount of usable energy. In an attempt to get around the voltage limitation, [Tom] built his own axial flux motor for the bike, using 3D printed formers for the coils and an aluminum rotor with embedded magnets. He expected torque to be severely limited, so he also machined a large sprocket for the rear wheel. He built a capacitor bank using six 2.7V 400F supercaps, only equivalent to the capacity of a single AA cell. Although it worked, the total range was only around 100 m at low speed. When he hooked the motor up to a conventional battery, he did find that it was quite usable, if a bit underpowered.

The controller for the DIY motor was not capable of doing regenerative braking, so he fitted the capacitors to another e-bike that does have regenerative braking. Using this feature, he was able to reclaim some power while slowing down or going downhill. Since this type of charging cycling is what supercaps are suited for, it worked, but not nearly to the level of being practical.

[Tom]’s projects are a popular feature here on Hackaday, and he has also experimented with supercaps in RC “rockets” and a flywheel for energy storage on the same bike.

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NASA Is Looking For A Next-Gen Astronaut Van

Since the Apollo program, astronauts making the nine mile trip from the Operations and Checkout Building to the launch pad have rode in a specialized van that’s become lovingly referred to as the Astrovan. The original van, technically a modified motorhome, was used from 1967 all the way to the first Shuttle missions in 1983. From then on, a silver Airstream Excella emblazoned with the NASA “meatball” carried crews up until the final Shuttle rolled to a stop in 2011.

With crewed flights for the Artemis lunar program on the horizon, NASA has put out a call to companies that want to build a new Crew Transportation Vehicle (CTV). As you might expect from rocket scientists, the space agency has provided an exacting list of specifications for the new CTV, down to the dimensions of the doors and how many amps each of its 12 VDC power jacks must be able to handle. Perhaps most notably, NASA requires that the new 8-seat Astrovan be a zero-emission vehicle; which given the relatively short distance it has to drive, shouldn’t actually be too difficult.

Interior of the Shuttle-era Astrovan

In the document, NASA explains that the new CTV could either be a completely new one-of-a-kind vehicle, or a commercially available vehicle that has been suitably modified, as was the case with the previous vans. But interestingly, it also says they’re open to proposals for refurbishing the Shuttle-era 1983 Airstream and putting it back into service.

This is particularly surprising, as the vehicle is currently part of the Atlantis exhibit at the Kennedy Space Center. Presumably the space agency thinks there would be some bankable nostalgia should Artemis crews ride to the pad in the same van that once carried the Shuttle astronauts, but given the vehicle’s history and the fact that it’s literally a museum piece, it seems somewhat inappropriate. This is after all the very same van that once carried the Challenger and Columbia crews to their ill-fated spacecraft. Luckily, the chances of anyone willing to turn a 1983 Airstream into a zero-emission vehicle seem pretty slim.

If you’re wondering, SpaceX carries astronauts to the pad in specially modified Tesla Model X luxury SUVs, and Boeing has already partnered with Airstream to build their own Astrovan II. There’s still no date on when Boeing might actually get their CST-100 Starliner up to the International Space Station, but at least the van is ready to go.

Open Source Autopilot For Cheap Trolling Motors

Quiet electric trolling motors are great for gliding into your favorite fishing spot but require constant correction if wind and water currents are at play. As an alternative to expensive commercial GPS-guided trolling motors, [AlexAsplund] created Vanchor, an open source system for adding autopilot to a cheap trolling motor.

To autonomously control an off-the-shelf trolling motor, [Alex] designed a 3D printed steering unit powered by a stepper motor to attach to the original transom mount over the motor’s vertical shaft. A collar screwed to the shaft locks the motor into the steering unit when the motor is lowered. The main controller is a Raspberry Pi, which hosts a WiFi hotspot and web server for control and configuration using a smartphone. Using navigation data from an e-compass sensor and a marine GPS chart plotter, it can hold position, travel in a specified direction, or follow a defined route. [Alex] is also planning to add the option of using a GPS module instead of a commercial plotter.

For an estimated total of $300, including the motor, this seems like a viable alternative to commercial systems. Of course, it might be possible to add even more features by integrating the open source ArduRover autopilot, as we’ve seen [rctestflight] do on multiple autonomous vessels. You can also build your own open source chart plotter using OpenCPN, which rivals commercial offerings.

Is There A Simpler Aircraft Than This Electric Paramotor?

The dream of taking to the air has probably ensnared more than a few of us, but for most it remains elusive as the safety, regulatory, and training frameworks surrounding powered flight make it not an endeavour for the faint-hearted. [Justine Haupt] has probably delivered the simplest possible powered aircraft with her Blimp Drive, a twin-prop electric add-on for her paragliding rig that allows her to self-launch, and to sustain her flights while soaring.

It takes the form of a carbon-fibre tube with large drone motors and props U-bolted to each end, and a set of brackets in the centre of laid carbon fibre over 3D-printed forms to which the battery and paraglider harness are attached. The whole thing is lightweight and quiet, and because of the two contra-rotating propellers it also doesn’t possess the torque issues that would affect a single propeller craft.

We’re not fliers or paragliders here at Hackaday, so our impression of the craft in use doesn’t come from the perspective of a pilot. But its simplicity and ease of getting into the air looks to be unmatched by anything else, and we have to admit a tinge of envy as in the video below the break she flies over the beach that’s her test site.

If you recognise Justine from past Hackaday articles, you’re on the right track. Probably most memorable is her rotary cellphone.

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Solar Powered Autonomous Tugboat For Rescuing Autonomous Vessels

[rctestflight] has built several autonomous boats, and with missions becoming longer and more challenging, he bought an inflatable kayak to serve as a dedicated rescue vessel. Instead of relying on outdated manual paddling, he built an autonomous solar-powered tugboat.

Towing test with kayak
♪ “Rum, treasure, ArduRover, Pixhawk 4 and so much solar, break of dawn till the day is over, the ship will surely go…” ♪

The tugboat uses a pair of molded fiberglass hulls in a catamaran configuration. The wide platform allows a pair of 100W solar panels to be mounted on top. It was [rctestflight]’s first time molding anything out of fiberglass, so there was quite a bit of trial and error going on. The mold was 3D printed in sections, aligned with dowel pins, and glued together. After the epoxy had cured, the mold halves could be split apart for easier removal of the hull.

As with most of [rctestflights] autonomous vehicles, control is handled by a Pixhawk 4 running ArduPilot/ArduRover. A pair of 76 mm brass propellers powered by brushless motors provide propulsion and differential steering. The motors get power from six LiFePO4 batteries, which charge from the solar panels via MPPT charge controllers. The hulls are covered with plywood decks with removable hatches and inspection windows. After a bit of tuning, he took the boat for a few test runs, the longest being 5.1 km with himself in tow in the kayak. At less than 5 km/h (3 mph) it’s no speedboat, but certainly looks like a relaxing ride. Many of [rctestflight]’s previous vessels were airboats to avoid getting underwater propellers tangled in weeds. It was less of an issue this time since he could just haul the tugboat close to the kayak and clear the propellers.

[rctestflights] are always entertaining and educational to watch, and this one certainly sets the standard for sea-shanty soundtracks at 13:32 in part two.

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3D Printed Scooter Zips Around

Tooling around downtown on a personal electric vehicle is a lot of fun, but it is even better when you do like [James Dietz] and ride on your own 3D-printed electric scooter. As one of the entries for the Hackaday Prize, RepRaTS (Replicable Rapid prototyper Transportation System) has a goal of doing for scooters what the original RepRap project did for 3D printing: provide a user-friendly design base that you can extend, modify, and maintain. It doesn’t even require power tools to build, other than, of course, your 3D printer.

The design uses threaded rods and special plastic spacers made to hold a large load. The prototype is deliberately oversized with large hub motors, with the understanding that most builds will probably be smaller. As you can see in the video below, the scooter seems to go pretty fast and handles well.

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