Autopilot arm on rudder post

[robbievardon]

"width of the walls" and "2 holes" suggested to me a pipe not a bar.

[carlo de leo]

Important notes
- the rudderpost IS hollow, is an aluminum tube
- If I glue the pieces together, like Uncivilized sugested, i'll not be able to remove the rudder anymore. I like the idea of making grooves on tche post, Will probably enhance the grip.

[foufou]

If the post is hollow and you drill through that doubles the area of contact of the bolt. If you add a compression tube inside the post then you can tighten the bolt more so long as you don't approach breaking. And of course use tefgel or other anti corrosion product and nylock nut

[UNCIVILIZED]

Originally Posted by carlo de leo

Important notes
- the rudderpost IS hollow, is an aluminum tube
- If I glue the pieces together, like Uncivilized sugested, i'll not be able to remove the rudder anymore. I like the idea of making grooves on tche post, Will probably enhance the grip.

You can bond them with an adhesive that's removable via simply applying the correct solvent. Or some others come of fairly cleanly with either heat, or cold. For example Sujjin (sp?) has removed a lot of fasteners & deck hardware bedded in 5200 via heat & a bit of force. A piano wire type garrot helps too, as do sharpened putty knives, or filet knives. They're flexible enough to get into a lot of otherwise inaccessible spots.
Plus, like I said, ain't many adhesives that like cold much. It's the 1st stop on the flow chart for anything accidentally bonded with epoxy. Dry ice, & CO2 are wonder tools sometimes

[Cadence]

Originally Posted by 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...

Someone said it is a lousy design and should have a key, I would agree. I am assuming the big screw is the set screw. I Would drill a dimple in the shaft for it to set in.
If it has stripped out have a nut brazed or welded to the arm. Either way use lock tight You might even consider doing the same on the other side. JMHO

[knockabout]

use the screw hole as the pilot with the arm clamped tightly in it's proper position / run a drill through the screw hole and out the other side clamp tightly with a through bolt

[Cadence]

Originally Posted by 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

I would nix that idea weaken the shaft. If a stainless shaft god bless him as far as getting through it without removing it and taking it to a machine shop. In that case putting in a key way would make more sense and getting an are with some beef to it.

[44'cruisingcat]

Use plenty of Tefjel or Duralac wherever dissimilar metals are in contact!

I believe a yacht "Megawat" sank when her rudder shaft broke due to galvanic corrosion caused by the A/P rudder reference unit.

[wingless]

Originally Posted by 44'cruisingcat

Use plenty of Tefjel or Duralac wherever dissimilar metals are in contact!

I believe a yacht "Megawat" sank when her rudder shaft broke due to galvanic corrosion caused by the A/P rudder reference unit.

The anodic index potential difference between bronze and stainless is low, so the galvanic corrosion won't be an issue for these metals.

Yes, galvanic corrosion can be a problem, so ensure the potential difference between dissimilar metals is less than 0.25V.

[44'cruisingcat]

The rudder shaft is aluminum.

[FutureStories]

One of these ought to do it

[wingless]

Aluminum to bronze is 0.5V and that is too much.

[UNCIVILIZED]

Originally Posted by FutureStories

One of these ought to do it Attachment 143891

Not quite sure on this, my bleeping swear jar's almost always full, so for f**k's sake, what use is it then? It's too packed to use to hold anything else.

[carlo de leo]

Originally Posted by 44'cruisingcat

The rudder shaft is aluminum.

Yes, but in the Edson Website I saw they build that tiller arm in aluminum also.

[carlo de leo]

Originally Posted by Cadence

Someone said it is a lousy design and should have a key, I would agree. I am assuming the big screw is the set screw. I Would drill a dimple in the shaft for it to set in.
If it has stripped out have a nut brazed or welded to the arm. Either way use lock tight You might even consider doing the same on the other side. JMHO

Yes, its a set screw. But already has a little hole for it to set (more Than a dimple) and this hole/dimple was stripped.