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The Cube - a driven wing sail catamaran sailing boat

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The Cube  a driven wing sail catamaran sailing boat  Designs Hears the cad models of the cube, a boat of my own design. There are two extremely thin hulls and 4 masts bearing 4 wing sails. Each wing sail can be independently operated but for the purpose of sailing that will move in unison. A very narrow transom holds some ever more slender rudders. The whole boat is built for speed. The sides of the hulls are completely vertical and the curves are just arks with a radius of about 15m. The hulls are 1.4m long and the rudders are 200mm long for a total water line length of 1.6m. Each hull has a full volume that is designed to displace a little more than the total mass of the boat. Theoretically, the boat could ride with one pontoon almost sunk and the other out of the water. This puts the water line just below halfway up the pontoons. "In theory" Each wing is 900mm tall and has a cord of 150mm. A total wing area of 0.54 sqm . The wings are the naca 0018 shapes.  Construct...
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Volantex Compass Robotic Conversion

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Motivated by the desire for a compact, traditional sailing boat that I could easily chuck in the car and launch with minimal prep, I acquired a second-hand Compass Volantex DG65-class RC yacht.  The previous owner had assembled it from a kit, but never quite finished the rigging.  So, having completed that little task I took it out for a sail using the included 2-channel RC transmitter.  This test sail verified it behaved nicely on the water and gave me a sense of how it might behave after conversion to robotic control!  The conversion would involve a few stages: Replace the original RC receiver and battery with a DroneLink motherboard, Power module and LiPo battery Rework the electronics bay to accommodate the electronics Replace the stock hatch with a new 3D printed hatch to house the battery and Compass module Integrate a GPS antenna and 915MHz dipole for the RFM69 radio Create a miniature wind vane using an AS5600 magnetic encoder  Overall layout: New Brains...
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Waypoint Navigation and Sailing Algorithm

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This post describes the underlying operation of the Sailing algorithm built into the DroneLink platform.  The functionality is spread across a number of logical modules, allowing for flexible usage in different types of devices, for example, motorboats requiring waypoint navigation, but not sailing logic. Waypoint Navigation All our boats (and other mobile robots) require basic waypoint navigation, implemented in the Waypoint module.  The module loads a list of lon/lat coordinates and associated target radii from a CSV stored in the ESP32 flash filesystem (waypoint.csv).  An example CSV and the resulting visualization is shown below for 4 waypoints: The Waypoint module subscribes to t he current lon/lat location,  from the GPS module, and uses this to calculate once the boat has come within the target distance of the current waypoint (10m radius for the first waypoint in the example above).  Once the target radius is reached, the next waypoint from the file w...
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Multi-interface Mesh Networking

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  Early in our development process, it became clear a flexible, robust mesh network would be an extremely useful feature of the DroneLink platform.  Two of the primary drivers of this were: Supporting multiple boats on the water at the same time (4 is our current record, plus support equipment) Extending the range of our lake testing beyond 100m from the base station This article outlines the background and operation of our solution, referred to as DroneMesh.  As prior reading, you'll need to understand the concepts in  DroneNode Modules and Loosely Coupled Pub/Sub Messaging . For general background see  Wikipedia Wireless Mesh Network .   Use Cases Planning ahead, we also mapped out the various use cases we were likely to encounter on the way to attempting the actual Microtransat challenge: Short-range (<50 m): Bench testing - all devices located within the vicinity of a single building and/or all within WiFi range of a single router Lake testing: ...
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Making the Keel of So Close

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Preface this is a blog about making a keel for a model boat. If you haven't read the post about that it won't make a lot of sense - Link to the original So Close post. So Close needs a high-density low heavy keel to keep it the right way up. Sounds easy to make something heavy, but it also needs to be a streamlined shape and have some means of fixing it to the two bits of sheet metal that it will hang between. Still doesn't sound very hard? Just 3D-print a mould of the shape and fill it with concrete, cast in a few bits of threaded rod and job done? Not quite so easy, So Close needs a 6kg keel, but the density of concrete is approximately 2.4kg/L, so 2.5 litres of concrete. Not a small mould to print, but not impossible if done in a few bits. The problem is when put under water it will displace 2.5 litres so now the concrete only weighs 3.5kg and it's huge. Now, of course, I could keep adding more and more concrete, not a very practical strategy, or pick a more dense su...
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