One Sailing Pulley To Rule Them All

March 6, 2026 by Bryan Cockfield 25 Comments

When thinking of humanity’s ability to harness wind energy, many people will conjure images of windmills from places like The Netherlands or Persia. But people have been using wind energy for far longer than that in the form of sailing ships. Using the wind for transportation goes back another four thousand years or so, but despite our vast experience navigating the seas with wind alone there is still some room for improvement. Many modern sailboats use a number of different pulleys to manage all of the rigging, but this new, open-source pulley can replace many of them.

The pulley, or “block” as they are sometimes called, is built with a polymer roller made out of a type of nylon, which has the benefit of being extremely durable and self-lubricating but is a bit expensive. Durability and lack of squeakiness is important in sailing applications, though. The body is made from CNC-machined aluminum and is composed of two parts, which pivot around the pulley’s axis to allow various ropes (or “lines”) to be inserted without freeing one end of the rope. In testing, this design outperformed some proprietary stainless steel pulleys of similar size.

Another perk of this design is that it can be set up to work in many different applications on a sailboat, whether that’s for hoisting a mainsail or pulling in a jib or any other task a pulley could be used for. It can also be stacked with others in many different configurations to build custom pulleys of almost any type, and can support up to 14 mm lines. For a sailor this could be extremely valuable, because as it stands each pulley on a ship tends to be used in only certain applications, and might also be proprietary from a specific company. This pulley is being released into the open-source world, allowing anyone to create them who wants one.

Thanks to [Keith] for the tip!

Continue reading “One Sailing Pulley To Rule Them All” →

A vaguely boat-shaped vehicle with three wheels and a mast. It sits in a barren-looking plain with short mountains in the distance

Sailing The High Steppes

October 10, 2024 by Navarre Bartz 29 Comments

Sails typically bring to mind the high seas, but wind power has been used to move craft on land as well. Honoring this rich tradition, [Falcon Riley] and [Amber Word] decided to sail across Mongolia in “Moby the Land Sailing vessel.”

Built in a mere three days from $200 in materials they were able to scrounge up the week before, the cart served as their home for the 300 km (~186 mi) journey across the Mongolian countryside. Unsurprisingly, bodging together a sailing vessel in three days to traverse uneven terrain led to a failed weld to the front tire, but a friendly local lent a hand to get them back on the road.

Built mostly out of plywood, the fully-laden cart tipped the scales at 225 kg (500 lbs) and could still be towed by hand. Under sail, however, they managed 70 km in one particularly windy day. They covered the distance in 46 days, which isn’t the fastest way to travel by any means, but not bad given the quick build time for this house on wheels. We suspect that a more lightweight and aerodynamic build could yield some impressive results. Maybe it’s time for a new class at Bonneville?

If you want to learn to sail in your own landlocked region, maybe learn a bit first? Instead you might want to build an autonomous sailing cart or take a gander at sailing out of this world?

[Thanks to Amber for stopping by to suggest some corrections!]

A bright orange sailboat with solar panels on the wing sail and the hull of the craft. A number of protuberances from the wing are visible containing instruments and radio equipment.

Saildrones Searching The Sea For Clues To Hurricane Behavior

July 29, 2024 by Navarre Bartz 26 Comments

Hurricanes can cause widespread destruction, so early forecasting of their strength is important to protect people and their homes. The US National Oceanic and Atmospheric Administration (NOAA) is using saildrones to get better data from inside these monster storms.

Rising ocean temperatures due to climate change are causing hurricanes to intensify more rapidly than in the past, although modeling these changes is still a difficult task. People on shore need to know if they’re in store for a tropical storm or a high strength hurricane to know what precautions to take. Evacuating an area is expensive and disruptive, so it’s understandable that people want to know if it’s necessary.

Starting with five units in 2021, the fleet has gradually increased in size to twelve last summer. These 23ft (7m), 33ft (10m), or 65ft (20m) long vessels are propelled by wing sails and power their radio and telemetry systems with a combination of solar and battery power. No fossil fueled vessel can match the up to 370 days at sea without refueling that these drones can achieve, and the ability to withstand hurricane winds and sea conditions allow scientists an up-close-and-personal look at a hurricane without risking human lives.

We’ve covered how the data gets from a saildrone to shore before, and if you want to know how robots learn to sail, there’s a Supercon talk for that.

Thanks to [CrLz] for the tip!

An image of a man in glasses in a circle placed on a black background. The title "Pierce Nichols: Teaching Robots to Sail" is on white lettering in the bottom left corner.

Supercon 2023: [Pierce Nichols] Is Teaching Robots To Sail

July 19, 2024 by Navarre Bartz 12 Comments

Sailing the high seas with the wind conjures a romantic notion of grizzled sailors fending off pirates and sea monsters, but until the 1920s, wind-powered vessels were the primary way goods traveled the sea. The meager weather-prediction capabilities of the early 20th Century spelled the end of the sailing ship for most cargo, but cargo ships currently spend half of their operating budget on fuel. Between the costs and growing environmental concerns, [Pierce Nichols] thinks the time may be right for a return to sails.

[Nichols] grew up on a sailing vessel with his parents, and later worked in the aerospace industry designing rockets and aircraft control surfaces. Since sailing is predominantly an exercise in balancing the aerodynamic forces of the sails with the hydrodynamic forces acting on the keel, rudder, and hull of the boat, he’s the perfect man for the job.

While the first sails developed by humans were simple drag devices, sailors eventually developed airfoil sails that allow sailing in directions other than downwind. A polar diagram for a vessel gives you a useful chart of how fast it can go at a given angle to the wind. Sailing directly into the wind is also known as being “in irons” as it doesn’t get you anywhere, but most other angles are viable.

After a late night hackerspace conversation of how it would be cool to circumnavigate the globe with a robotic sailboat, [Nichols] assembled a team to move the project from “wouldn’t it be cool” to reality with the Pathfinder Prototype. Present at the talk, this small catamaran uses two wing sails to provide its primary propulsion. Wing sails, being a solid piece, are easier for computers to control since soft sails often exhibit strange boundary conditions where they stop responding to inputs as expected. Continue reading “Supercon 2023: [Pierce Nichols] Is Teaching Robots To Sail” →

Sailing (Directly) Into The Wind

February 6, 2024 by Bryan Cockfield 22 Comments

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.

Continue reading “Sailing (Directly) Into The Wind” →

Polynesian Wayfinding Traditions Let Humans Roam The Pacific Ocean

February 1, 2024 by Lewin Day 24 Comments

Polynesian cultures have a remarkable navigational tradition. It stands as a testament to human ingenuity and an intimate understanding of nature. Where Western cultures developed maps and tools to plot courses around the world, the Polynesian tradition is more about using human senses and pattern-finding skills to figure out where one is, and where one might be going.

Today, we’ll delve into the unique techniques of Polynesian navigation, exploring how keen observation of the natural world enabled pioneers to roam far and wide across the breadth of the Pacific.

Continue reading “Polynesian Wayfinding Traditions Let Humans Roam The Pacific Ocean” →

Learn Sailing Mechanics Without Leaving Dry Land

January 20, 2024 by Danie Conradie 31 Comments

The ancient art of sailing can be very intimidating for the uninitiated given the shifty nature of wind. To help understand the interaction of wind direction and board orientation, [KifS] designed a hands-on sailing demonstrator that lets students grasp the basics before setting foot on a real sailboat.

The demonstrator uses a potentiometer as a tiller to control a model sailboat’s angle, while another stepper motor adjusts the position of a fan to simulate changing wind directions. With an Arduino Uno controlling everything, this setup affords students the opportunity to learn about sail positioning and adjusting to shifting winds in an interactive way, without the pressures and variables of being on the water.

[KifS]’s creation isn’t just about static demonstrations. It features four modes that progressively challenge learners—from simply getting a feel for the tiller, to adjusting sails with dynamic wind changes, even adding a game element that introduces random wind movements demanding quick adjustments. [KifS] mentions there are potentials aspects that can be refined, like more realistic sail response and usability, but it already achieved the main project goals.

There are a myriad of potential ways to add new tech to the ancient art of sailing. We’ve seen a DIY autopilot system, full sensor arrays, and an open source chart plotter. It’s even been proven you can have a wind powered land vehicle that travels faster than the wind.