Need help understanding construction of my rudder stock

MikeCalypso

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This is the rudder stock on my Dufour Arpege (1974). I recently acquired the boat and it has some play in the tiller (basically this piece has a bit of loose movement before it moves the rudder). The large hole left to right carries the bolt that attaches the tiller. However there was nothing in the smaller hole front to back. Should there be a bolt in here? If I place a bolt in it stops the play in the rudder. However I'm confused that there wasn't anything there and also confused how this whole construction actually works. I can't seem to take it apart and I don't understand what it would look like inside or how it attaches to the rudder tube. Also should I be greasing between the two flat surfaces?


IMG_20240419_171055412.jpg
 

johnlilley

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I suspect there might be a roll pin in the lower hole for a locating position, the main tiller bolt doing the majority of the work once fitted. The roll pin may be partially broken or worn. I would have expected some form of thrush washer between the rudder tube top & tiller stock as it is likely that the tiller stock is bearing on the rudder tube top flange. The only other possibility is that the tiller stock is threaded onto the rudder stock & located correctly with the tiller bolt or roll pin, unusual to see that though..
 

MikeCalypso

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Thanks so much for your reply.

So I've had more of a look and can't see a roll pin in there but like you say it might have had its day. Also agree a thrust washer would probably be sensible.

Any thoughts on how I might be able to get remnants of a roll pin out? I'm loathe to drill a bigger hole.

The hole for the tiller bolt is smooth inside so that doesn't go through the rudder tube so it must just be the lower hole that links them.

As I said if I fit a bolt through it stops the play so I guess I'll go with that for now unless that rings any alarm bells. If I ever need to take it off I'll have to look into all this further but for now to keep sailing I hope I'm ok just to put a bolt through and it'll be sound.

Maybe if there is an old pin in there that not up to much then the bolt will do the job of opening it out to fill the gap.

Unfortunately without taking it off I won't be able to get a washer in unless I could somehow split open one side and work it in.
 

johnlilley

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I cannot imagine that a small dia roll pin would be all that holds the tiller stock onto the rudder stock. Roll pins are near impossible to drill as they are so hard but if one was present, then a pin drift of the hole size should clear it out if it is present.

Unlikely but possible the the top of the rudder stock is square and the tiller stock has a square recess but virtually impossible to produce easily when there, are alternate options. However, if that was the case then the tiller stock would lift off vertically once any retain pin was removed. That would possibly mean the rudder could drop through though.....

If you are positive that the tiller bolt does not pass through the rudder stock as well it does not leave a lot of material to fit the rudder stock and even less reliability with regard to the transfer of the high torque required to control the rudder
Did you say that the tiller stock does rotate slightly on the rudder stock which stops if if fit a bolt into the "roll pin" drilling.
Intriguing... Perhaps an owner of an Arpege has the answer.
 

Rappey

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I came across a westerley cirrus that had no rudder. It appeared to be similar arrangement to yours. The block to mount the tiller to was on the cockpit floor with tiller attached but the other bolt that went through the block and rudder stock had sheared allowing the rudder to drop out whilst the boat was on a swinging mooring . The bolt head and nut with thread were on the cockpit floor and assume the rest of the bolt went down with the rudder.
Yours has play and is still there so like you, i wonder how it is put together ?
Would a roll pin ever be used on a part that does require some form of dissasembly at times ?
 

MikeCalypso

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Wow, what a find with that old French magazine. Although I have to say I am sadly struggling to see what is going on in the images due to the quality.

I agree it would seem crazy for just a roll pin to be used to apply the large torque required to turn the rudder.

It is skeg hung with a foot on the skeg so won't fall out and I wonder if the tiller stock is mostly just seized on the top as I certainly cant lift or prize it off either.

The play is unusual. Quite a bit of turning force has to be applied and then it suddenly jumps to the other direction with quite a clunk. It's probably about 5 or 10 degrees or play.

As I said I'm going to just go with a bolt through there for now as it doesn't seem to ring any alarm bells for anyone.

I did see these replacement parts for the Centaur which do suggest smaller bolts holiding the tiller stock to rudder stock and a larger one holding the tiller on to the tiller stock


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DinghyMan

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Wow, what a find with that old French magazine. Although I have to say I am sadly struggling to see what is going on in the images due to the quality.

I agree it would seem crazy for just a roll pin to be used to apply the large torque required to turn the rudder.

It is skeg hung with a foot on the skeg so won't fall out and I wonder if the tiller stock is mostly just seized on the top as I certainly cant lift or prize it off either.

The play is unusual. Quite a bit of turning force has to be applied and then it suddenly jumps to the other direction with quite a clunk. It's probably about 5 or 10 degrees or play.

As I said I'm going to just go with a bolt through there for now as it doesn't seem to ring any alarm bells for anyone.

I did see these replacement parts for the Centaur which do suggest smaller bolts holiding the tiller stock to rudder stock and a larger one holding the tiller on to the tiller stock


View attachment 176925

That is one I made for a Westerly W22 - the dome headed bolt doesnt go through the rudder stock shaft, its just a pivot point for the Tiller, the block is held to the rudder shaft by the two stainless grub screws which located into dimples cut into the rudder shaft, it was supplied as part of a restoration project and included a tool for locating and drilling the dimple points in the shaft

The French mag seems to show both the pin and the bolt both going through the rudder shaft; looking at the tiller block where its been cut in half it looks like its been split along teh line of the roll pin and appears to show the bolt going through the middle of the rudder shaft - not very good images though

Screenshot 2024-05-13 230747.png
 
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