Boat pulls to starboard

[MJH]

Originally Posted by wgerstmyer

Just took out a new to us Freedom 36 and the wheel pulls badly to starboard, not even close to tracking a straight line (perhaps worse at higher RPMs. Nothing interfering with the pulleys below decks, autopilot not engaged or on, wheel spun easily on land and now too.
ANY thoughts are greatly appreciated as no one we know has heard of this. Thanks, Will and Tasha

Is this something different from your pre-purchase on-the-water trial ride? Does this happen under sail as well? Did the previous owner say anything about a rudder repair, grounding, etc. that might have been done? Is there anything in the surveyor's report that might account for it? I would call him for his opinion.

My only experience was after the rudder was rebuilt and the boat would then pull noticeably to port...I had to haul the boat again, remove the rudder, and send it back for adjustment...very frustrating.

Good Luck

~ ~ _/) ~ ~ MJH

[GordMay]

You guys ought to get together.
➥ https://www.cruisersforum.com/forums...ml#post3420295
➥ https://www.cruisersforum.com/forums...ml#post3420334

[Pauls]

The solution to this is simple. It is a solution commonly used on aircraft, called a trim tab. Cut a piece of stainless sheet metal, not too thick, and epoxy it to the the rudder so that its trailing edge protrudes several inches from the rudder trailing edge. Bend it so that the water flow against it counters the turning force you are experiencing under power.

This is a bit of a trial and error thing - try it, adjust as necessary and try again. When sized and adjusted properly it will eliminate this problem.

[Sailmonkey]

Originally Posted by Pauls

The solution to this is simple. It is a solution commonly used on aircraft, called a trim tab. Cut a piece of stainless sheet metal, not too thick, and epoxy it to the the rudder so that its trailing edge protrudes several inches from the rudder trailing edge. Bend it so that the water flow against it counters the turning force you are experiencing under power.



This is a bit of a trial and error thing - try it, adjust as necessary and try again. When sized and adjusted properly it will eliminate this problem.

And create a new problem while under sail.

[waterman46]

My old Cal29 with tiller steering had so much helm pull when motoring that the tillerpilot was constantly having to pull the tiller back to center. We added a shock cord to counter this force to be used whenever under power.

[PuttingDoctor]

Originally Posted by GordMay

You guys ought to get together.
➥ https://www.cruisersforum.com/forums...ml#post3420295
➥ https://www.cruisersforum.com/forums...ml#post3420334

I agree Gord. This makes me wonder why only the two of us caught this. Which way does it pull again???

[maine50]

I helped a friend take a 40' sailboat down ICW from new England to Florida with resulting extensive powering time. The boat pulled right so much it was tiring to steer.
He investigated rudder shape etc. It turned out the steering cable was too slack. It was tightened and problem largely went away.

[KP44]

Originally Posted by wgerstmyer

Just took out a new to us Freedom 36 and the wheel pulls badly to starboard, not even close to tracking a straight line (perhaps worse at higher RPMs.

Thanks, Will and Tasha

Prop wash. Nothing more. It will likely vanish in neutral and/or with the engine shut off.

[SaylorMade]

Originally Posted by Pauls

The solution to this is simple. It is a solution commonly used on aircraft, called a trim tab. Cut a piece of stainless sheet metal, not too thick, and epoxy it to the the rudder so that its trailing edge protrudes several inches from the rudder trailing edge. Bend it so that the water flow against it counters the turning force you are experiencing under power.

This is a bit of a trial and error thing - try it, adjust as necessary and try again. When sized and adjusted properly it will eliminate this problem.

Well, that is one way to slow down a boat...

[Pauls]

Regarding the comments on a trim tab creating a problem under sail and slowing the boat, wrong on both counts.

The rudder offset under power is due to the propwash, which is a column of high velocity water flowing over one area of the rudder. A trim tab located in the center of this column has a large effect while under power, but with the engine off the water velocity in that area drops a lot and the tab has little influence.

Slowing the boat - you're kidding, right? A tab with a few square inches of area at the back of the rudder? You will not be able to measure the difference.

[wgerstmyer]

Thanks all for the great replies. See you in the Vinalhaven area later this summer. Tash and Will, SV Nirvana

[malbert73]

Originally Posted by wgerstmyer

Thanks all for the great replies. See you in the Vinalhaven area later this summer. Tash and Will, SV Nirvana

That’s all? [emoji3]

Did you figure out that’s it’s only under power?

[skenn_ie]

Unbalanced rudder, or you may need to angle the propshaft to compensate for propwalk.
How is it under sail, assuming that you have sails.

[Tigue]

Interesting. Mine does the same thing but mine pulls to port at higher RPM. My plan was to have the max prop serviced next time I hoist the boat for service. I like Jdeuel idea. I will try that myself to confirm my suspicions.

[skenn_ie]

Originally Posted by Dove1955

Just like when a single engine pulls to one side in a full power climb so it can be with a boat. In a plane you have to apply slight right rudder in a full power climb, or adjust the trim. Any proper moving through a fluid (air or water) will do this to some degree. Newton-every action has an opposite and equal reaction. Outboards have an adjustable small fin (slag) just above the prop to counteract this force, not sure if there is anything for sailboat. Powerboats with twin engines use counter rotating props to solve this. Good Luck !

With most aircraft, there is a lot more fin/rudder above the fuselage than below. Also, in a climb, (high AoA) makes it even worse, although you have more authority above t/o speed. That shouldn't be the case with a boat rudder, though it COULD be the cause of adverse yaw.