Whipstaff vs. Wheel.

[SamSam]

Originally Posted by kenJ

If you look at the diagram, Bill PKS indicates push the whipstaff left to go left as designated by the red arrow. I was just saying that if that is his desire, it won't work as drawn.

Most whipstaffs that I have seen are mounted o a side bulkhead and work in a fore/aft motion so which way they turn the boat is less of an issue. Maybe because I grew up using tillers, their movement seems normal to me. I think it would be very disconcerting and take quite a while to get used to a whipstaff mounted in the center of the boat that turned the boat opposite the way you pushed it.

Maybe he meant when you push the whipstaff port, the boat will go starboard (red arrow)

[Bill PKS]

Red Arrow--- (( Rough Sketch attached ))
The Geometry of the cable and block rigging is intended so that.....
If you pull the Top of the Whip staff toward port ( per the red arrow),
the bottom of the staff pulls the Port Cable FROM port toward starboard, and releases away the starboard side Cable.
Following the port cable thence pulls on the port side of the quadrant, rotating the rudder shaft ( CCW viewed from above ) and thence the aft end of the blade toward starboard.
Assume there is a tiny tiller on top of the Rudder Shaft.
Pulling the Tiller to Port rotates the aft end of the rudder blade to starboard.
So, pulling the Top of the Whip staff or a Tiller would result in the same rotation of the rudder blade around the vertical pivot ( rudder shaft.) .
Moreover, as the cable loop is pulled on either side, it releases by the same amount on the other side, thence the distance of movement of the cable pull to rotate the quadrant is compensated by the same amount of slack from the opposite direction .
Arc of movement of the Whip Staff Bottom, would be set the same as the arc of movement of the quadrant.
Leverage would be obtained by the differential length of the Staff above pivot point, but I don't know the ratios without some ciphering.
Shouldn't this work??
Bill PKS

[Bill PKS]

RED ARROW again.
The Red Arrow is the direction of pull on the Top of the staff, not the direction of the boat.
Just like a Tiller, pull to port turns to stbd.
( Have seen staffs steering outboard motors with the cable attached above the pivot. In this instance, the cable is attached below the pivot.)
Bill PKS

[SamSam]

With the cable attached above the pivot point makes the boat turn in the direction staff is pushed- push left, boat turns left. A quadrant is needed on the bottom of staff to keep cable pull constant, as Alan says in post #2. Another solution is for cable stop to slide in elongated notch in bottom of staff. Tension is usually kept on system by springs to keep cable in pulleys. One danger of cable systems with high powered motors on high speed boats is failure of one of many connections can allow abrupt, uncontrolled high speed turns.

Do you plan to use a system like this for something?

[alan white]

Moreover, as the cable loop is pulled on either side, it releases by the same amount on the other side, thence the distance of movement of the cable pull to rotate the quadrant is compensated by the same amount of slack from the opposite direction .
Arc of movement of the Whip Staff Bottom, would be set the same as the arc of movement of the quadrant.
Leverage would be obtained by the differential length of the Staff above pivot point, but I don't know the ratios without some ciphering.
Shouldn't this work??
Bill PKS

To see whether it would work as shown, imagine exaggerating the diagram. Imagine the pivot of the whipstaff ten miles above the cable. Pull the whipstaff down to one side where it's horizontal. You've just pulled both sides up several miles, but the cable is a lot shorter than that.
Always exaggerate mechanisms to see what happens.
In this case, the use of a quadrant at the tiller end should tell you something. The quadrant is exactly like a wheel, except meant for a reciprocating motion that precludes the need for a full circle.
The action is linear and velocity of rudder movement doesn't change relative to cable velocity. This is also how the whipstaff end should work. Constant velocity means a degree of arc of the whipstaff always results in a degree of arc of the rudder. More importantly, cable length remains constant with a quadrant below the whipstaff.
It's not vital to have a whipstaff-end quadrant, It is, however, the easiest and most practical way to set up the system to work reliably. You can make a simple quadrant from ply/epoxy. It doesn't have to be made from cast aluminum'

[Bill PKS]

- In this instance the Whipstaff is planned to work like a Tiller,,, pull to Port turns to Starboard etc.
I like that because, with a weather helm you are pulling to the win'ward, and on a heel you can hike on the high side using an extension to steer.
However,,, since the staff would be located in a Center Cockpit,,would it be better to emulate a Wheel where the Helm is turned in the direction you want to go.
As previously noted,, I have seen Fishing boats with a bottom pivot whip staff, which turn in the direction the Staff is pushed.
Given the unusual nature of a Whip staff ,, what would be better?
( It wouldn't be hard to rig the cabling to do either. )
- Also thinking the staff could be designed to insert and lock into a socket at the cockpit sole, or then be disconnected and removed from the socket. This would clear the cockpit when desired.
- Another idea. Use of an automatic pilot steering system, would allow the helm to be located most anywhere with a Tugboat type toggle. When under power, or just sailing along... You wouldn't even have to sit out in the rain ,, unless you wanted to.

Bill PKS