Rudders again

[Ixneigh]

I've been sailing my M a lot last few weeks. How sure are we that the Ida rudders are the ideal?
Seems to me like the rudders need to be maybe 4 inches wider with an inch of that forward of the turning axis. And made out of something that won't flex. Im thinking ply core with a lot of biaxial epoxy fiberglass. I'd also taper the tips slightly. Thoughts?
Ix

[Be Free]

I would be very interested to hear your ideas. I have one rudder that will need some work very soon and I'm not adverse to building something completely different if the effort is justified.

[NiceAft]

Bill,

Ix’s post is coming up on nine years old. You may wish to either email or PM him to make him aware of your interest?

[OverEasy]

Hi All!

Yeah, it’s an old post but it does bring up some thoughts….

On some aircraft there is a smal portion of airfoil ahead of the rudder ( or elevators or ailerons) pivot axis to aerodynamically balance the forces of the movable rudder. ( the static portion is technically the vertical stabilizer and the movable part is the actual rudder)
This is a calculated balancing act as too much airfoil forward of the pivot will either make the rudder difficult to impossible to control….
Whereas no airfoil ahead of the pivot only makes it hard to move but still controllable….
Making the airfoil longer aft of the pivot makes the rudder movement effect more powerful but harder to move.

This all applies to boat rudders as well.
One shouldn’t want a rudder too easy OR too hard to control.
Personally I believe that when Rodger was working through the rudder designs for the Macs he used his experience and design capabilities to get to a well balanced design providing a good responsiveness and controllability.

Just my opinion and I’d love to see this explored more by our community….

Best Regards,
Over Easy

[NiceAft]

Just my opinion and I’d love to see this explored more by our community

….

You forgot to add “of engineers”.


Me, I turn the wheel to the left, the boat turns to port, I’m happy.

[Be Free]

It was not my intention to "raise the dead" on this one but I'm glad to get a response from those in the know.

Has anyone actually tried this or any other rudder mods on a Mac? Did it improve anything? I think that Inquisitor was working on 3d printed rudders a couple of years ago but that's the only one I recall.

Now my secret is out. I'm working my way back through all of the old posts on the board and I'm currently in mid-April 2016.

I know that Ixneigh is still active so I hope he can fill in the blanks. Did you try the modified rudders and did it make a difference?

[NiceAft]

Is the weather bad in Steinhatchee? Is that why you have so much time on your hands? Up here in Philly, we quite literally had snow, sleet, freezing rain, and rain yesterday; some of which were at the same time. We depend on your sailing escapades. Close the computer, get out of the chair and go on the water.

[OverEasy]

[Be Free]

Is the weather bad in Steinhatchee? Is that why you have so much time on your hands? Up here in Philly, we quite literally had snow, sleet, freezing rain, and rain yesterday; some of which were at the same time. We depend on your sailing escapades. Close the computer, get out of the chair and go on the water.

Other than being foggy and almost no wind the weather is beautiful right now. It's not the weather that has me tied to this chair.

I need to do some maintenance on the bunks on my trailer. They are due to be replaced and I'm not comfortable leaving town until they are replaced.

"But you don't need to leave town. You live a mile from the boat ramp'" I hear you thinking. That is true, but Helene (you remember her coming by last fall) destroyed all of the the docks (along with almost everything else near the river) with her 20' storm surge and filled the ramps with debris. Without a dock to tie the boat to while I take the trailer back to the house (or retrieve it from there) the one ramp that's been cleared just taunts me every time I drive past.

I have all of the parts for the bunk repair and I hope to get them installed when I get back into town in a week or so. After a quick trip out to Albuquerque with an even quicker detour to San Francisco, I hope to be in the water mid March. That's the plan anyway.

If the ramps are back by then it will probably be a Gulf trip; if not the other option is a week or so on the St Johns. It's been a couple of years since I've been over there and I sort of miss it.

Sorry to keep you all waiting.

[Ixneigh]

Hi. Regarding rudders.
I’ve tried tree different types. The OEM rudders, the rudder craft HDPE, and some very heavy solid oak rudders I had made in a shop to the rudder craft shape.
Here are my feelings. Please note. I no longer feel the boat needs larger rudders. Depending on use, it needed the stub keel I installed. In other words that fixed the problems I was having. If I bought another M that would be the first chore.

The factory rudders are light, easy to pull up and pretty rigid. They stall easily. The rounded tips are not that great. Once the boat is up to speed, they are fine. I was having a little bit of a broach issue running down wind.
The rudder craft rudders are heavy, and flex a bit. Not sure if that’s bad. They don’t stall quite as easily. I’m mean, you have to know the boats quirks. It took me years to loose my keelboat habits. They help with down wind a bit.
The solid wood rudders are insanely heavy. I was pretty happy with them however the glass sheathing was not staying on. Do not use glass sheathing on hardwood. I still have them. I may try to remove the glass and just coat them with epoxy and no glass. It was hard to asses if these were “better” than the rudder craft rudders. My boat is now a terrible choice to compare any of these questions anyways since she is much different than a stock boat, and tuned for the type of sailing i do most.

I will opine that everyone who sails a lot should do the pivot mod described in the other recent rudder thread. It will help prevent plate bending and the rudder does not bind. It’s not an easy mod though.

Ix