dual rudder ? pros cons ?

[lucozader]

i have a mini rio and love it's dual rudder

i am thinking of putting a dual rudder on my pro boat widowmaker and maby a pro boat mini cat

are there any disadvantages to dual rudders ?

[Fluid]

Drag and weight - neither of which are good for mini boats' performance.



.

[BondoBrushless]

How about dual rudder on a larger boat, 40+" ?

Scrubbing a little speed to expected but anything truely negative ?

Thanx

[Fluid]

Depends on the boat. Most 40" boats do just fine with a single rudder, it just needs to be scaled to the boat. Extra rudder drag not only slows the boat down directly, it can and will pull the bow down and requires more up angle on the prop - reducing efficiency. In addition to extra drag there is also more cost and complexity.

I remember reading in the early 1980s (!) about how one boater found that Marine Specialty's big dual rudder setup calmed down chine-walk on a mono. The consensus of the experienced boaters was it did that because it slowed the mono down to below the chine-walk speed.....

If you like the looks of dual rudders then by all means go ahead and mount them....this hobby is about enjoyment. It isn't - nor should it be - all about speed at any cost.


.

[785boats]

The only boat I've ever run dual rudders on was my old 'X-Wing'.
To reduce the drag I just made them shorter so that the total length in the water added up to just slightly more than the lenght of the one blade that would have been used. It was an experiment & they were only flat blades but it got around the corners ok.
Enforcer sell a twin rudder setup for the big gas powered Enforcer hulls. So they must have some sort of reason for that. Probably just the 'Bling' factor.

http://www.google.com.au/imgres?imgurl=http://www.modelgasboats.com/images/stories/issues/Oct2007/WHHMagnum57/20071015_0125_frontpage.jpg&imgrefurl=http://www.modelgasboats.com/Magazine_Content/Boats/WHH_Magnum_57/&usg=__IRqoxe_EVS2S5zrsPRFS1072-Dk=&h=167&w=250&sz=16&hl=en&start=37&um=1&itbs=1&tbnid=j7DrBCyFd8c-9M:&tbnh=74&tbnw=111&prev=/images%3Fq%3DEnforcer%2Btwin%2Brudders%26start%3D2 1%26um%3D1%26hl%3Den%26sa%3DN%26rlz%3D1T4GGLL_enAU 350AU350%26ndsp%3D21%26tbs%3Disch:1
Cheers.
Paul.

[BondoBrushless]

I bought a really nice and highly adjustable twin rudder set up and just not sure if I should bother with it ? I bought it when my knowledge was in it's infantcy, not that it's much better now :olleyes:

I planned on using this on my 42" boat that will be running 8s,possibly 10s depending what ESC I decide on.

The rudders are 6" and I realize they can be cut down but is this a over engineered piece,should I get something simpliar in design ?

http://i88.photobucket.com/albums/k192/bondonutz/RC%20Pics%20for%20FORUM%20purposes/P8090001.jpg

http://i88.photobucket.com/albums/k192/bondonutz/RC%20Pics%20for%20FORUM%20purposes/P8090002_01.jpg

http://i88.photobucket.com/albums/k192/bondonutz/RC%20Pics%20for%20FORUM%20purposes/P8090003.jpg

[FE Wannabe]

Bondo,

The main issue with this setup as I see it, is the water pickup that is attached below the strut. It sits right in front of the prop and would cause turbulence which would prevent much of the prop from seeing clean water. I see that being potentially a bigger issue than the dual rudders in this setup. Just my 2 cents.

Brad

[BondoBrushless]

Brad,

I could always grind that pick up off smooth and finish with a dab of JB Weld ?

I had planned on a different water pickup anyway because I just dont trust those tiny holes in the murky nasty water we have here.
I had planned on useing 1, maybe 2 of these;
http://www.offshoreelectrics.com/proddetail.php?prod=ose-80410
So if thats the only issue your concerned with then thats pretty good so far ?
Thank you for your valued opinion.

[785boats]

There is a bigger issue with the water pickup. And that is the fact that the water is forced up & around the prop shaft.
Unfortunately a lot of the water forces its way past the bearing & up the drive shaft/stuffing tube & into the hull. Been there done that. It pushes all the grease/oil out with it & makes a helluva mess too.
Just my experience with the Sea Predator. So I fitted a propwash pickup to the strut.
I know mine is only a single rudder but it is the same strut.
Cheers.
Paul.

[BondoBrushless]

That settles it then, I'll grind that baby flat and eliminate it.
Thanks for the pics, interesting looking boat !