Sailing (Directly) Into The Wind

Humans have been sailing various seas and oceans for thousands of years, and using boats for potentially even longer than that. But as a species we wouldn’t have made it very far if it was only possible to sail in the same direction the wind is blowing. There are a number of methods for sailing upwind, but generally only up to a certain angle. [rctestflight] wondered if there was some way of sailing straight upwind instead and built this rotary sail craft to test the idea.

Normally a boat sailing upwind will sail approximately 45° into it, then “tack” 90° across the wind until they’re at another 45° angle from the wind, this time facing the opposite direction. This back-and-forth nature is not the most efficient path, so this vessel uses a few propellers to bypass the traditional sail. The first iteration, built on a sleek catamaran hull, uses a large propeller to catch the wind’s energy, then transfers it mechanically through a set of shafts to an underwater prop.

It took a few tries to get the size and pitch of both propellers narrowed down to where the boat would move forward into the wind, but move it does. A second major iteration of the build uses a single shaft with no gears, with the trade-off that neither propeller is facing an ideal direction, but this has the added benefit of the boat naturally pointing itself upwind.

While none of the designs are speed demons, the concept is sound enough. It’s just that, in most cases, performing multiple tacks to get upwind is acceptable compared to the extreme efficiency losses and drag from propeller-driven sailing crafts like these. A more effective way of propelling a boat upwind, at least using modern technology, might be to trade sails for solar panels.

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High Voltage Ion Engines Take Trip On The High Seas

Over the last several months, we’ve been enjoying a front-row seat as [Jay Bowles] of Plasma Channel has been developing and perfecting his design for a high voltage multi-stage ionic thruster. With each installment, the unit has become smaller, lighter, and more powerful. Which is important, as the ultimate goal is to power an RC aircraft with them.

There’s still plenty of work to be done before [Jay] will be able to take his creation skyward, but he’s making all the right moves. As a step towards his goal, he recently teamed up with [RcTestFlight] to attach a pair of his thrusters — which have again been further tweaked and refined since we last saw them — to a custom catamaran hull. The result is a futuristic craft that skims across the water with no moving parts and no noise…if you don’t count the occasional stray arc from the 40,000 volts screaming through its experimental thrusters, anyway. Continue reading “High Voltage Ion Engines Take Trip On The High Seas”

Waterjet-Powered Speedboat For Fun And Research

There are a lot of cliches about the perils of boat ownership. “The best two days of a boat owner’s life are the day they buy their boat, and the day they sell it” immediately springs to mind, for example, but there is a loophole to an otherwise bottomless pit of boat ownership: building a small robotic speedboat instead of owning the full-size version. Not only will you save loads of money and frustration, but you can also use your 3D-printed boat as a base for educational and research projects.

The autonomous speedboats have a modular hull design to make them easy to 3D print, and they use a waterjet for propulsion which improves their reliability in shallow waters and reduces the likelihood that they will get tangled on anything or injure an animal or human. The platform is specifically designed to be able to house any of a wide array of sensors to enable people to easily perform automated tasks in bodies of water such as monitoring for pollution, search-and-rescue, and various inspections. A monohull version with a single jet was prototyped first, but eventually a twin-hulled catamaran with two jets was produced which improved the stability and reliability of the platform.

All of the files needed to get started with your own autonomous (or remote-controlled) speedboat are available on the project’s page. The creators are hopeful that this platform suits a wide variety of needs and that a community is created of technology enthusiasts, engineers, and researchers working on autonomous marine robotic platforms. If you’d prefer to ditch the motor, though, we have seen a few autonomous sailboats used for research purposes as well.

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Printed Catamaran

If you want to send some instruments out on the lake or the ocean, you’ll want something that floats. Sure, if you need to be underwater, or if you can fly over the water there are other options, but sometimes you want to be on the surface. For stability, it is hard to beat a catamaran — a boat with two hulls that each support one side of a deck. If that sounds like the ocean sensor platform of your dreams, try printing the one from [electrosync].

The boat looks super stable and has a brushless motor propulsion system. The design purpose is to carry environmental and water quality monitoring gear. It can hold over 5 kg of payload in the hull and there’s an optional deck system, although the plans for that are not yet included in the STL files.

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