Re: [Amel Yacht Owners] Re: Steering Failure on 1992 SM72 "Aloha"

Craig Briggs

Excellent question, Herbert, and one I've wondered about, too.
My wheel goes about 3 turns from stop to stop. That's 3 X 360° = 1080°. My rudder moves about 30° each way or 60° stop to stop. That's an 18:1 mechanical advantage, which is why Herb has to push so hard on the rudder to spin the wheel and move the rudder. (to say nothing of wheel diameter, rudder center of effort and friction)  
Granted the linear drive has a lever arm at the quadrant giving some mechanical advantage, but it seems it still must take much more force than the rotary drive.
Interesting discussion.
Cheers, Craig

---In amelyachtowners@..., <herbert@...> wrote :

Hi Bill, I think I could not express myself very clear, try to say it again, sorry for my English: 

when the rudder is moved by the rotary drive (or by the steering wheel) it moves very smooth, you can turn it with the "little finger".  If I try to move the rudder (on the hard) by pushing or pulling it I need quite a lot of power until it moves (and of course the steering wheel turns also). So I thought, that the system is designed in a way that it runs very smooth when the power transmission goes from wheel to rudder but not the other way round (eg like a worm gear...).

If the linear drive turns the rudder by moving the quadrant I thought that there might be a lot of friction until the steering wheel gets turned by the ultraflex cables.  Is it true that the linear drive also turns the steering wheel when working - I assume yes?

This is not a question how the Autopilot works but how the Amel Steering works

thx, herbert

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