Autopilot arm on rudder post

[carlo de leo]

Hi again!

Recently, I had a little problem with The Autopilot arm attaching the rudder post.
Happens that the arm slides through the Post (see picture attached).
Both pieces are aluminum, the arm embrace (squeeze) the Post by 2 screws and nuts. The Post is a tube in wich a "Big" Screw crosses the arm
and pins the post through one of the walls . That is supposed to be a security screw I think. When the arm slided, The big screw was knocked out and the autopilot had no proper action anymore. The width of the walls (post and arm) was not sufficient to stand the forces of this lonely screw.
Two solutions came me to mind, but I think that if anyone has the same kind of system, a better idea of attachment could pop up here.
1. periodicaly check for looseness of the nuts on the arm and leave it like it is.
2. make a locker pin through out the two parts (arm and rudder post), this would weaken the rudder post because two more holes would be necessary to transfix it.
3. Cruisers forum Thoughts...

[neilpride]

The pin is there to grip in the arm, if the pin is gone or broken you need to fit a new one, otherwise you rely in the 2 screws at the arm and this is not a good idea...

[Neptune's Gear]

Sorry, but that is a poor design. It's Likely to continue to give issues. It should have a keyway on the shaft and be keyed on. Bolts and screws often shear or tear in this application.

[wingless]

How about a nice heavy-duty cast bronze part, like this one?

[carlo de leo]

Originally Posted by Neptune's Gear

Sorry, but that is a poor design. It's Likely to continue to give issues. It should have a keyway on the shaft and be keyed on. Bolts and screws often shear or tear in this application.

Matt,

How could I have a keyway if the post is hollow? this would weaken the post i suppose. A positive keyway on the post wouldn't let me retrieve the rudder anymore.

Thanks

[carlo de leo]

Originally Posted by wingless

How about a nice heavy-duty cast bronze part, like this one?

Wingless,

Nice design! It seems to have more grip on the post, but I didn't notice any keyway nor screw transfixing it. It wouldn't slip also?...

Thanks!

[DeepFrz]

Yes, that cast bronze or cast aluminum arm could also slip although judging from your drawing would be more secure than what you have. Perhaps a picture of your setup and a better description of your rudder post would help us help you. If the rudder post is hollow then I think you must have a bolt that goes all the way across with a nut on the other side.

[fallingeggs]

Originally Posted by carlo de leo

Wingless,

Nice design! It seems to have more grip on the post, but I didn't notice any keyway nor screw transfixing it. It wouldn't slip also?...

Thanks!

Once ordered, Edson will put in a keyway, set screw or through bolt, whichever you like. They are pricey, but quality (and nearly the only name in the game).

I went through bolt. Drilling will be fun...

[Sailmonkey]

Originally Posted by fallingeggs

Once ordered, Edson will put in a keyway, set screw or through bolt, whichever you like. They are pricey, but quality (and nearly the only name in the game).



I went through bolt. Drilling will be fun...

Jefa also supplies tiller arms for autopilots.

http://www.pyiinc.com/jefa-autopilot/tillerlevers.html

[carlo de leo]

Deepfrz and Fallingeggs,

A through bolt is what I mentioned that I have in mind, but I'm not secure if drilling 2 holes would not weaken the Rudderpost.

I'll try to attach a picture.

Thanks!

[UNCIVILIZED]

Obviously the more surface area that's clamped, the better the arm's grip on the post. And this can be further enhanced either by bonding the two together, using something like a flexible adhesive. Or by putting a friction enhancing material in between the mating faces of the post & arm.

Also, I've no idea how thick the walls of the rudder post are, but might the post's walls have grooves mechanically cut into them. Ones designed to mate up with grooves in the clamping surface of the tiller arm. So that each one functions as a small keyway. And together they'd lock the arm & shaft together much like a chain where it wraps around a sprocket.

[robbievardon]

I don*t think a through bolt will weaken the rudder post much unless you use a huge bolt.Think of your safety line stanchions. If you are really worried force a wood dowel down into the rudder post. Just interference fit.

[wingless]

Isn't the rudder a solid rod, not a pipe? Both of my rudders are built using a solid stainless rod.

[Bill Seal]

I'd drill the hole all the way through and use a tight-fitting bolt, but first, use high-strength Loc-Tite on the mating surface between the arm and the rudder post

[topmast]

I liked Unciv's idea. How about a length of light gauge springy steel wire bent WWWWW and wrapped around the shaft. Clamping should imbed it enough to act like keyway