Rudder toe in.

[Colwyn D]

I've finally got around to measuring the rudder alignment and find they are parallel, no toe in or out. The tie bar between the rudders has a central boss about 12" long and a collar each side of it. I expected there to be a left and right hand thread and to rotate the boss to either lengthen or shorten the tie bar. That's not the case and both ends appear to be same thread.
I'd have a play and find out but things are pretty seized up so I'd like any info. before proceeding.
How do you adjust the length?

 

[Glory]

Remove one end from a tiller, loosen one, or both, ends and adjust as needed. If frozen use heat.

 

[davidwigler]

This is new to me. What's wrong with parallel? Why would you induce drag?

 

[dottieshusband]

I thought toes in, the water, was a good thing! Apologies to Zac Brown..I'm off to FLIBS!

 

[Avenger]

They need a little loading to keep them from vibrating and wearing stuff out. Not much though. A half inch is plenty, and yes they can extract a significant drag penalty if they have excessive toe.

 

[krush]

First, what is tow in definition...the leading edge is closer than the trailer edge?

Second, I think I read some theory argument once about toe in can help efficiency a little beacuse it helps straiten the prop swirl....or maybe that was something else. I think the discussion started with which is better, inboard or outboard turning screws. Now, I've talked to some tug captains and they said it makes a big difference on tugs. /more random info.

 

[Avenger]

Same as in automotive, toe-in is leading edges in. As far as prop swirl, tugs often have leading rudders too. Could be a very complex question. Then again they often have Kort nozzles also. Sounds complicated.

 

[luckydave215]

The need for toe in (or toe out) is not obvious.
Water flow speed and direction under the hull are probably not simple or easy to model, and likely vary considerably with speed.
Conventional wisdom (which may be full of crap) says that the water is flowing out from centerline even at the transom due to the running angle. Therefore toe in reduces drag.
I don't know if anyone has actually done any tow tank work on our hulls to verify this.

 

[bobk]

The need for toe in (or toe out) is not obvious.
Water flow speed and direction under the hull are probably not simple or easy to model, and likely vary considerably with speed.
Conventional wisdom (which may be full of crap) says that the water is flowing out from centerline even at the transom due to the running angle. Therefore toe in reduces drag.
I don't know if anyone has actually done any tow tank work on our hulls to verify this.

I saw an article that discussed this issue. Toe in was said to reduce lift, toe out increased lift because of the direction of the induced water flow. Sounds reasonable, but I wonder about the magnitude of the effect. Sorry, I didn't keep the reference.

Bobk

 

[Colwyn D]

Reason for messing with rudders is turning boat one way is slightly harder on the wheel than the other. Just in case there's some servo effect from rudder angles, toe in/out, I thought I'd try it. Steering at the dock or slow speed is ok.