Will this crazy idea make any difference?

[Diegoboy]

Before I try to figure out "how", I need to know if it's worth the effort. Please provide any input you may have.

I saw this picture and then the idea hit me.


Will installing a gyro on the rudder to keep the rudder vertical at all times even when the mono leans in a turn. Will this improve handling? will it screw up handling? will it make no difference at all?

[egneg]

I guess reaction time would make or break this idea.

[AndyKunz]

If the rudder is under constant gyro control, it will counteract any yaw (or roll, depending on what axis you install it).

If you have the gyro mixing with the rudder, the boat will track a nice smooth arc, but it will have to lean into the turn. That's not a problem - they're supposed to do that.

Why do you think you need one?

Andy

[ozzie-crawl]

so basically the rudder stays in one position and the boat pivots like on axis?
at least it should counter act any lift the rudder would normally give
would be interesting if it worked, i wonder if it would help settle a mono if it gets chine walk.
only problem i see is the rudder helps stop the boat from rolling
if the hull starts to roll and the rudder moves the opposite way it would council out any holding force the rudder has

[Jesse J]

You could always hardwire the angle of the rudder to the amount of turn... predicting the angle of bank and add another servo to swivel the rudder mount. This might be simpler and a way to see pretty quickly if it would make a difference.

I wonder if letting the gyro "think" for you might lead to some unexpected feedback loops...

Definitely a head scratcher and I would like to see the outcome. Needless to say, it would have to be an inline setup... or dual rudders

[Diegoboy]

That is an excellent idea Jesse. Eliminate the Gyro. I like it

[Tuslow1]

Not trying to get off the subject but what is that boat and do you have anymore shots of it, looks hot!!!! I wonder how you would make it work being that you are going to have to mount the rudder like a rotating hendge that would only use one hole through the transom or a hole and a slot, the single hole sounds like it may be WEAK and the hole and slot sounds like it may LEAK!
But what do I know...... It's your idea, Go for it!!!

[Flyguy55]

Many yrs ago I did something similar . I made a rudder bracket that I could tilt the shaft and still adjust the rudder blade angle . I adjusted the shaft with the bottom of the rudder shaft closer to the transom then the top of the shaft and adjusted the rudder blade vertical . Its a lot like ackerman steering on a car . On a car it tilts the wheel into the turnwhen you turn ,
On my boat I tried about 15 - 20 deg of angle of the rudder shaft I adjusted the rudder to stay vertical when the boat would lean into a turn.

When I ran the boat , it did the opposite . The rudder turned , but the boat stayed level . It handled ok , and didn't slow down in the turns , but was uncomfortable to drive. Visually it felt like the boat would roll over to the outside of the turn.

I only raced it one time that way . I would expect your system to do about the same.

Dick Roberts

[Jesse J]

I bet the driver dudes got sick as well... interesting results, would not have guessed. What boat was it?

[sundog]

While we're on this subject, there was a time I wondered why a boat didn't lean the Other way, as centrifugal force would have it. But reasoned the rudder was what was pushing the hull into a tilt. Then I built a jetboat and it would lean WAY on over - so much you could see the intake. And it didn't even Have a rudder. Hmm...mo' thinkin'.

Diego, at some point in the turn would the rudder will have to cross paths with the propwash? When you are heeled on over in a turn, would that cause more drag to have another inch of rudder in the water? What would be the advantage(s)?

But I like your idea of using a gyro - that would be advantageous in eco (V shaped track) in a river or windy situation.

Here's the jetboat heelage: http://www.youtube.com/watch?v=sTLyC8tQAqw

[AndyKunz]

Why?

The CG of the hull is above the water. All rotations will be centered on the CG.

The rudder is below the water.

When the rudder is turned, it is putting a force on the hull below the CG toward the outside of the turn. That means the boat is going to bank into the turn. It is also putting a force pushing the rear of the hull toward the outside of the turn.

But that's OK (in fact, good) because the hull will turn nicely.

Back in the early days of flying, ailerons "proper use" was to keep the plane level while turning with the rudder. Turning with ailerons was "hot dogging" it and frowned on (from what I remember, it could cause a British pilot to lose his wings). One day somebody showed the physics of what was going on. Suddenly it was OK again.

If the reason you want to do this is because you think your boat is rolling too far over, make sure your hull is correctly designed. Otherwise, all the laws of physics are in your favor for this being a STABILIZING force on your hull.

Andy

[Flyguy55]

I bet the driver dudes got sick as well... interesting results, would not have guessed. What boat was it?

It was a Deep Vee from Bandit boats with a Novarossi .21 in the mid 90s . It wasnt what I expected either . I think it was fast in the turns because the bow didnt go down and the ride attitude stayed about the same . The race was at Fremont CA . Randy Naylor was there , but I don't know if he'd remember.

I was losing interest after about 20 yrs racing nitro and didn't continue to develope it . There may have been a sweet spot where it would lean in some and still be fast . I think I still have the boat.

Dick

[Unsullied_Spy]

If you're talking about installing a heading-hold style helicopter gyro and using that on the steering it will make the boat go straight when you want it to go straight, that's about it. I've seen them used on high speed onroad cars to make fast and minute adjustments to the steering to make it more controllable at speed and on drifters to basically do the driving for you. In a boat I suspect it will go straight in rough water without having to make adjustments to the steering but Mono hulls are designed to bank in a turn.

[Flyguy55]

My rudder did like your picture , The rudder was near vertical when the boat lay over on its right side in a turn . From my experience my vote is
none of the above .

[HOTWATER]

I have already thought about this as I have mounted my rudder offset to the right a bit to keep the rudder at a better angle to the water in the turns...

Here are a couple pics of this on my ETTI Oriental Dragon (I have not run it yet)