Wheel load on autopilot

[Graham_Wright]

Having re-installed the rudder and checked the cable routes it occurred to me that a lot of the autopilot effort is used overcoming the friction and inertia in the "manual" connections.

Is there any means of disengaging the manual quadrant when under autopilot control?

As my autopilot drives a tiller separate from the quadrant, I could lock the quadrant to the tiller (the reverse load on the autopilot actuator is very low by comparison). I have in mind some sort of dog clutch disengaged electrically when the A/P is active. The two inputs would have to be aligned before engaging the lock but that should not be difficult.

Anyone done/do that?

 

[sailorman]

Having re-installed the rudder and checked the cable routes it occurred to me that a lot of the autopilot effort is used overcoming the friction and inertia in the "manual" connections.

Is there any means of disengaging the manual quadrant when under autopilot control?

As my autopilot drives a tiller separate from the quadrant, I could lock the quadrant to the tiller (the reverse load on the autopilot actuator is very low by comparison). I have in mind some sort of dog clutch disengaged electrically when the A/P is active. The two inputs would have to be aligned before engaging the lock but that should not be difficult.

Anyone done/do that?

there is very little drag load on my system, 1.75 turns lock to lock

 

[Graham_Wright]

there is very little drag load on my system, 1.75 turns lock to lock

What system is that? Mine is cable with a total of 6 pulleys. Hydraulic would possibly have been easier but having experienced failures at sea with that and with rod, I thought cable would be safer.

I should add that turning the wheel manually requires very little effort and the ruder is very free.

 

[sailorman]

What system is that? Mine is cable with a total of 6 pulleys. Hydraulic would possibly have been easier but having experienced failures at sea with that and with rod, I thought cable would be safer.

I should add that turning the wheel manually requires very little effort and the ruder is very free.

from quadrant to 1 sheave to each wire to change direction up the pedestal & onto the chain/sprocket

 

[cmedsailor]

I should add that turning the wheel manually requires very little effort and the ruder is very free.

But that doesn't make sense unless I realised it wrong. The wheel turns easily the rudder without effort but with the autopilot there's a lot of effort. How can this be possible? Have you ever tried turning the rudder itself with your hands (preferably in the water so there's water resistance)? Does it feel light?

PS: Only I can think of is that the autopilot turns the rudder via a "thin" shaft so it feels difficult whereas your hands turn a large a wheel.

 

[Graham_Wright]

But that doesn't make sense unless I realised it wrong. The wheel turns easily the rudder without effort but with the autopilot there's a lot of effort. How can this be possible? Have you ever tried turning the rudder itself with your hands (preferably in the water so there's water resistance)? Does it feel light?

PS: Only I can think of is that the autopilot turns the rudder via a "thin" shaft so it feels difficult whereas your hands turn a large a wheel.

The lever advantages are very different. The wheel is 1000 mm in diameter and the tiller around 280 long.
The wheel takes 3 1/2 turns lock to lock and the tiller moves around 320 mm.

I think that makes the ratio 34:1. Perhaps I am worrying too much. When I power up the A/P, I'll see if it struggles.

 

[sailorman]

The lever advantage are very different. The wheel is 1000 mm in diameter and the tiller around 280.
The wheel takes 3 1/2 turns lock to lock and the tiller moves around 320 mm.

I think that makes the ratio 34:1. Perhaps I am worrying too much. When I power up the A/P, I'll see if it struggles.

I have a 6000+ it always copes in any heavy weather ( not tried down hill on a blow)

 

[Talbot]

biggest load on an autopilot is normally because the sails are not balanced.

 

[Graham_Wright]

biggest load on an autopilot is normally because the sails are not balanced.

We're drifting again!

 

[sailorman]

biggest load on an autopilot is normally because the sails are not balanced.

my rudder is like a house door & sails are always balanced