Flettner Rotor for small craft - Design and Build Prototype

The Bottom end - bearing and end plate.

I manged to locate a steel, 5 mm end plate for the aluminium column. Usually they only sell Aluminium end plates

Its only held on by some rather small Philips head screws, that I intend to replace with 12mm high tensile boats.





The problem with replacing the Phillips heads with bolts, is that there is a Countersink hole in the end plate, to ensure self alignment.
So, I hunted down some convex stainless washers to put under the high tensile bolt.

Rapid push for mechanical bottom end.



Motor fitted



First Test Run



Made a Youtube "Short" of it in operation
This site cant embed the link , maybe because its a Short.

https://youtube.com/shorts/gSaMcCGlO_s

Congratulations

@rwatson Congratulations on the Flettner Rotor. I am new to this forum but have read a good deal of your post. I had some questions about a previous project you were working on regarding the Mac 26. Any way you could message me?

FSS yachts said:

@rwatson Congratulations on the Flettner Rotor. I am new to this forum but have read a good deal of your post. I had some questions about a previous project you were working on regarding the Mac 26. Any way you could message me?

Click to expand...

I tried to Message you, but got a message saying I was unable to. You will have to message me.

rwatson said:

I tried to Message you, but got a message saying I was unable to. You will have to message me.

Click to expand...

Hi @rwatson I am new on the forum so apparently it does not allow me to message until I am a more established member. Could you shoot me an email? I would love to see where you got to on your search for the improved planing hull motor sailer. Thank you! brooks[a]whalentennis.com

FSS yachts said:

Hi @rwatson I am new on the forum so apparently it does not allow me to message until I am a more established member. Could you shoot me an email? I would love to see where you got to on your search for the improved planing hull motor sailer. Thank you! brooks[a]whalentennis.com

Click to expand...

I sent an email to
brooks@whalentennis.com
No acknowledgement yet, might want to check your Spam

Big Step. A good value boat of the right dimensions for this project came up for sale, so I plunged in and bought it.


After a lot of thought, I have managed to dream up a potential layout for the rig, including provision for trailering setup.


In the bottom left corner of the "sail" plan, I have a table showing the combinations of calculated performance versus rotor size. This is based on a two metre tall tower,
I am favouring a .8 metre diameter, as the rotation speed is lower at the optimum outputs. I may end up doing a .6 metre diameter, once I evaluate the build difficulty.
There isn't anything to stop me making up several rotor sizes, and installing them for anticipated wind conditions.

Following on many months after the two biggest challenges to any project, Health problems and Enthusiasm, I tried an interesting exercise.

Not being willing to spend a fortune on Engineers yet, I thought I would run my "mast" concept using Google AI, to discuss the practicality of using a stage Truss.

I was super pleased to be given not only some hard facts, but also some really useful ideas and figures.
I'll attach them here as part of the history. Note - I had to save the AI conversation as a "web page", or HTML
The problem is that HTML files are not allowed to be attached. So, I compressed it to a Zip file, so anyone interested in perusing the AI session, will need to download it and "unzip" it.

The most obvious observation was
"Using a standard entertainment box truss as a sailboat mast introduces massive structural risks because entertainment trussing is engineered exclusively for static downward gravity loads, not the dynamic, omnidirectional aerodynamic and righting forces of a sailing vessel."

and

"An internal fixed spindle supporting a spinning Flettner rotor changes the engineering dynamics entirely. By using a revolving cylinder, you have effectively eliminated the torsional rigging twists of a traditional sail, but you have replaced them with a massive, constant bending moment at the base caused by the Magnus effect."

It even calculated the loads that could be present.

and

It then goes on to analyse the method for fastening into the boat, which was one of my "puzzle points", and offered great ideas



Anyway, now I have to design a two part internal truss "box" that will enable me to compress the 1 metre of Truss below deck into a rigid plywood cage, to maximise the load resistance.

Originally, I was going to be content to just drift around in light winds for testing, but I think I will now go through the exercise of squeezing the most value out of the the current material, and if needs be , test it to destruction.

In any future experiments, including larger vessel installations, this AI observation


will be countered with this AI advice


I even found a Chinese Truss company that could do the building. I'll insert them here for my future easy reference.

Ray I took the liberty of turning your compressed HTML file into a PDF.

HelmutSheina said:

Ray I took the liberty of turning your compressed HTML file into a PDF.

Click to expand...

Darnn. I thought you had made it better, but unfortunately, you got the same problems as me. Dialogue boxes and adverts obscuring the conversation
Thanks for trying though



Edit - I will put a reference link to the problems I had trying to save an AI "conversation", for future reference

The other thing that migh be critical, is that I open my .html file in the Brave Browser, which does away with advertisements.
I wonder if Paid AI tools make this process easier.