21 mono rudder

[Mike Byer]

I've seen some good boats with the rudder at an angle, that is not vertical when viewed from the rear, at an angle that favors how the boat would roll to the right side in a turn, but not quite vertical if the boat is resting on the right side of the hull bottom. Seems like DT built some hardware that had the rudder at an angle on the Twincraft. Your thoughts.

Mike B

 

[Ron Olson]

John Finch covered that in one of his books, Advanced R/C Model Boating. At the bottom of page 16 it shows the setup. What it shows very quickly is if the boat bottom has a 20 degree angle, the rudder should be tilted 10 degrees. I don't think that I've seen it in use but possibly others have tried it.

Briefly, according the article it helps if the hull runs loose in the corners.

 

[John Finch]

It puts less force on the bow while cornering and keeps more rudder in the water at the same time. It can also act as a trim tab on the right side of the boat to fight torque when a little left rudder is used to keep the boat tracking straight in the straightaway. The rudder can do a lot of things on a mono. I am presently working on a mono that relys solely on the rudder for trim.

 

[Mike Byer]

I went with the rudder straight with the world. So far so good. I used a Speedmaster 3/16 stinger outdrive for the first time. It moves the prop way back, and made a long rudder bracket to get the rudder behind the prop. Trim tabs but no turn fin. Handles the chop really well and turns good. All this on a $60 hull off ebay from China. Speeds and pix to follow if anyone is interested.

Mike B

 

[anthony_marquart]

When I ran monos I did what that book said. I actually never made one vertical but all my monos ran very well. If you read the section on monos in that advanced rc boating book I think you'll do the same. It makes very good sense.