Wheel clutch/freewheel

[Nekton73]

About 10 years ago Edson developed a wheel disconnect method that allowed the helm to freewheel without having to disconnect or remove the wheel. I'm unable to find anything on their website now and I'm not even sure it ever went into production.


Anyone know if it is still sold, or ever was? Any other manufacturers make something that accomplishes the same thing? My google searches are not turning up anything except 'how to' instructions on how to remove a wheel. Perhaps I'm not using the right terms.

https://www.youtube.com/watch?v=YTdgdnYZXVE

[Lepke]

If you don't find anything, try a machine shop in a commercial port. Older autopilots like Wood-Freeman were connected to the wheel shaft and the wheel was disconnected to spin free. If not, a spoked wheel could catch clothing and take you to the deck.
Also check used boating gear stores.

[stormalong]

Edson has a similar system many years ago. It did not incorporate a brake and the cogged hub was on the shaft outside of the pedestal. It incorporated a longer shaft and the wheel could slide away from the hub after loosening. I saw one of these on a boat but I don't remember how the wheel was prevented from sliding forward and re-engaging accidentally.

After a discussion with an engineer on another sailboat I experimented with removing the wheel on long passages to reduce load on the autopilot. The load reduction was very significant. It was a great idea until a squall required me to take control from the autopilot and the delay putting the wheel back on was a problem.

Later I bought a much smaller diameter wheel - 24" vs the 54" that was standard on my boat. That was also a big reduction in the gyroscopic load on the autopilot. It was also very difficult to steer manually vs. the mechanical advantage of the 54" which resulted in a very light helm. I sailed many thousand of sea miles with that smaller wheel.

[flee27]

This is interesting. I have never thought about the load the wheel puts on the auto pilot. It make sense once I read it though. On a long passage it could really add up in terms of energy consumption and wear on the auto pilot system. This would be an interesting study to see the real world differences between different wheel diameters and weights. Maybe there is a practical reason to get a carbon fiber wheel...

Foster

[goboatingnow]

The difference isn’t major. The inertia is small. Certainly removing the wheel is rather silly

[stormalong]

Originally Posted by goboatingnow

The difference isn’t major. The inertia is small. Certainly removing the wheel is rather silly

Not true at all. I am not a physicist but by observation I can see it is very significant. I would not have thought so either but after the discussion with a mechanical engineer cruising friend and my observations I can see the difference. Also this would be a big impact on a wind vane self steering system due to the added force needed to overcome the inertia of the wheel.

Do we have any physicists out there that can do the calculations on how much power is required to start and stop the rotation of a large diameter wheel?

[flee27]

I would think it is the water dripping theory. Its a accumulation of a relatively small force over a long period that would add up to make a possible difference. Like stormalong suggests is would be interesting at least to know what the actual forces were.

Interested

Foster