Improved turning?

[DanLew]

Sorry, I did search the forum to find info, but couldn't find an answer.
Does this work (attached sketch)?
Would like to try it on a Trumpeter Seawolf conversion.
Is my "crabbing" vs turning assumption correct?
Thanks.

[He Who Shall Not Be Named]

Your 'crabbing' scheme will produce a lateral force, but will not effect a turn as there is no 'lift' into the turn from the hull as it's angle of attack to the water will be next to zero.

The second drawing, the one on the right, is the way to go -- this will yaw the boat into the turn, a situation where the entire boat acts as a lifting foil in the direction of the turn owing to the large angle of attach to water flow about the yaw axis

M

[RCSubGuy]

Kind of a neat idea, actually, especially if the additional front rudder is removable for display. You could also do a removable rudder extension for the lower rear rudder as well. Putting this in place and measuring performance would be a terrific tool.

[Kazzer]

I actually saw a Trumpeter Seawolf fitted with a clear silicone molded extension that fitted over the rudder. That boat had a lousy turning circle and the larger prop made a huge difference. Methinks there is potential for this idea.

[redboat219]

You could always say it's an experimental boat.

[trout]

Go for it! The cool thing is it can be removed. So you can run with and without and give us a report of the difference. I like out of the box thinkers, what is your next step?

[He Who Shall Not Be Named]

Credit, were credit is do: Art Broader, of the SubCommittee, if not the originator, is certainly the man who popularized the forward rudder here in the States. His otherwise poor turning ALFA was a very sharp performer in the water through the aid of such a control surface.

M

[vital.spark]

I have the Trumpeter Seawolf and the and I couldn't turn it in a 20' pool! All I did was cut an extension out of Plsticut sheet and taped on the lower rudder when I drove it! When finished for the day, just untaped it! What's the problem??

[redboat219]

Do this

http://www.google.com/patents/US5058521

[Kazzer]

I have the Trumpeter Seawolf and the and I couldn't turn it in a 20' pool! All I did was cut an extension out of Plsticut sheet and taped on the lower rudder when I drove it! When finished for the day, just untaped it! What's the problem??

Perfect!!!!!

[DanLew]

I have the Trumpeter Seawolf and the and I couldn't turn it in a 20' pool! All I did was cut an extension out of Plsticut sheet and taped on the lower rudder when I drove it! When finished for the day, just untaped it! What's the problem??

I ran out of duct tape...

Even with the add-on surfaces shown, this Seawolf was a slow turner. With the fore-rudder addition, the ugly add-ons will be removed.
Also replacing the rudder servo with a bit more robust one. Stern rudder will be a cap over the scale rudder, with small setscrew to hold it in place. Fore-rudder has a threaded shaft that is screwed into a bolt inset in the hull. Midway the length of the connecting pushrod is a guide-eye on the hull.
Designed to be quick-on/quick-off.
Pics of work in progress...

[trout]

Nicely done.

[He Who Shall Not Be Named]

Well done, sir. Nice neat work.

M

[ffr2608]

Make the rudder attachment with 2 magnets. Simple and you can hide it until the boat is in the water.

D

[Kazzer]

Make the rudder attachment with 2 magnets. Simple and you can hide it until the boat is in the water.

D

Now why didn't I think of that?