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Magnus Effect Boat (X2)

So, this is an experimental boat uses a really weird method of propulsion to move using only the wind and a spinning rotor. Here’s the video if you haven’t seen it yet.

What is the Magnus Effect?

The Magnus Effect is a super cool bit of physics. It’s commonly found being used in ball games, such as football or tennis, where a sports player curves the ball by introducing a spin on it. In my video I showed how when my friend Joe kicks a football, he uses the Magnus Effect to curve its trajectory

The Magnus Effect can be a very powerful force. I’ve mentioned in my Magnus Effect plane video that air can be dragged around and deflected to subsequently pushes a spinning object the other way. In that aeroplane video, I showed how I could create enough lift to fly an aircraft with this effect, so I decided maybe it would be fun to build a boat too! It might even be simpler and easy (but I was wrong)!

My First Attempt at Building a Magnus Effect Boat

I based my boat around a stable catamaran sailing boat. I printed out eight hull sections, which took around 12 hours of printing. Then I sanded the hulls and superglued them together.

I made sure these porous PLA hulls were both fully water tight by using this leak sealer spray followed by plenty of black spray paint, which I thought would make the boat look pretty cool. Next, I made some little connector pieces that could be used to join the hulls together with some 12 mm carbon tubes.

I gathered all of the other other major components I’d designed and printed and then essentially then had a big Lego kit to assemble.

The rotor mechanism uses a couple of bearings either side of a pulley that fit around another carbon tube. This was mounted to the front of the deck but could be moved about if needed later thanks to the standardised pattern of mounting holes I drew on these components. I might have to do this more in the future. It’s always helpful to have some build in ‘adjustability’ to my projects so I can play around with the setup of a vehicle at the test field without having to go back to my workshop to rebuild something and then go out again.

Next I printed a motor mount, installed a motor, built a rudder and tested everything thoroughly. With that, I could pack my things and then head off to find some water for a very first test run.

Learning From This Project

Key things to take away from the results of the testing shown in the video are:

I need a keel! Keels are key for boats like this to rotate around. Without one, you get a somewhat uncontrollable boat that you can’t keep facing at an angle against the wind.

It’s more about sailing than I realized. As with the above point, this was a hard introduction to sailing type vessels and I should have been more on it with thinking about this vehicle as a sailing boat rather than self powered.

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