Twin mono ruder set back

[Jesse J]

Anybody have experience with rudder setback?
I assume that screw separation should be minimal, and rudder should bare some perfect distance back.

Boat is baby sv43, I?m thinking of having 48-52mm props 1/2? separation, set back from transom 3.5? or so and debating on how much distance between props and center mounted rudder... 2in? 3in? More, less?

Please, respond if you have experience and/or data to support recommendation.

Thanks
Jesse

[Jesse J]

Nobody?

[785boats]

Hi Jesse.
I have only built one twin mono. A 44" Wasabi.
I don't know if the setup is optimum, so I was a bit reticent to make any suggestion as I thought others with more experience would have by now.
The struts I used placed the leading edge of the props at 2-1/4" from the transom.
The rudder leading edge is 4" from the transom. The longest standoff bracket that I had at the time. Not much of a gap between the trailing edge of the props & the rudder. Should possibly be more.
Here's the thread if it is any help.
https://forums.offshoreelectrics.com...ghlight=wasabi

Cheers.

[Jesse J]

Hey Paul, thanks for chiming in!
Man, what a beast! How did she feel while driving? Turns, straights, in the air?

[785boats]

It actually feelt pretty good in both the turns & the straights. Although I didn't turn too tightly around the bends.
The driving in the air was a bit anxious. but she kept running.
Unfortunately I haven't run it much since then. The offshore class that it was built for, never really got off the ground at our club.
Motors & ESC's were robbed for other projects.

[Jesse J]

What was actual distance between prop shafts?
and it looks like the rudder was about an inch behind the back of the props?

[785boats]

The shafts are 2.5" apart.
The leading edge of the rudder is almost level with the trailing edge of the props.
As I said, it should probably be a bit further back, but I have no idea what the optimum distance would be.
Cheers.