tapered rudder vs. straight?

[driftah]

advantages and disadvantages anyone?

[Darin Jordan]

A tapered rudder tends to drive the nose down more when it's turned, similar to adding castor to the rudder angle.

Straight rudders, when straight... don't... For turning, with a straight rudder, if you want to pick the nose up in the turns, you tuck the rudder under slightly. If you want to push the nose down in the turns, you angle it back slightly.

[driftah]

so for a 32 mono a straight is prolly better methinks

[Darin Jordan]

so for a 32 mono a straight is prolly better methinks

Generally speaking, I always try to use a straight bladed rudder that can be adjusted for caster angle.

One of the other aspects of a tapered rudder, however, is that you have more blade chord in the water at lower speeds. As the boat lifts out of the water, you end up with less rudder chord in the water.

I'd go with the straight rudder...

[Make-a-Wake]

Straight rudders, when straight... don't... For turning, with a straight rudder, if you want to pick the nose up in the turns, you tuck the rudder under slightly. If you want to push the nose down in the turns, you angle it back slightly.

WOW.............I thought the rudder tucked would push the nose down??? Thanks for clearing that up. I have my Rudder tilted back just a bit(bottom farther back than top) and I am spinning out a bit, should I tuck it more???? Thanks!

[Darin Jordan]

WOW.............I thought the rudder tucked would push the nose down??? Thanks for clearing that up. I have my Rudder tilted back just a bit(bottom farther back than top) and I am spinning out a bit, should I tuck it more???? Thanks!

Try it! :)

Here is a REALLY good read on the entire subject concerning all of the adjustments you can do... it's written by John Finch, the gentleman who designed the WildThing Mono:

http://www.modelpowerboat.com/content.php?122-RC-Model-Boat-Hull-Attitude

From that article, here is what he shows for rudder angle:



It's definitely the opposite of what you would think, or at least what I would think, it would be...

[Make-a-Wake]

I will give it a shot next time out, thanks Darin!

[dana]

WOW.............I thought the rudder tucked would push the nose down??? Thanks for clearing that up. I have my Rudder tilted back just a bit(bottom farther back than top) and I am spinning out a bit, should I tuck it more???? Thanks!

I always thought the same thing. I've since tucked all my rudders in.

[dana]

I think it has more to do with turning. Having the rudder tilted back will cause more lift in the turns I believe

[Fluid]

Yes, tilting the rudder only has an effect on hull trim when turning. Tilting it back will raise the transom in turns, usually not what you want with a mono but helpful with hydros. Realize that you have to tilt the pivot, not just the blade, so sometimes shims are needed between the rudder bracket and the transom.


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[ray schrauwen]

Thanks for this info. I had forgotten this and have been doing things backwards for some time.

[Make-a-Wake]

Realize that you have to tilt the pivot, not just the blade, so sometimes shims are needed between the rudder bracket and the transom.


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Got it!!

[dana]

Yes, tilting the rudder only has an effect on hull trim when turning. Tilting it back will raise the transom in turns, usually not what you want with a mono but helpful with hydros. Realize that you have to tilt the pivot, not just the blade, so sometimes shims are needed between the rudder bracket and the transom.


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Could you elaborate or show a pic jay? I'm not 100% sure what you mean here. Thanks )

[Make-a-Wake]

I have often wondered why a rudder hinge couldnt be setup like this crude photo I just made which would make it tuck "more" as the rudder is turned due to the angle of the hinge.

[dana]

Wait I get what fluid is saying now. I'm a little slow today lol