rudder discussions

[commanderpete]

Here's some measurements of that replacement rudder. At the shaft, the wood is rounded out and slightly overlaps the shaft. I measured the width of the rudder from the outside of the shaft.

The original rudder on Commander # 200 is slightly shorter (42 1/2) and wider (18) than this rudder.

The shaft is milled out the same as the plan in the Manual: key at top (2 x 1/4) and pin at bottom (3/4 x 3/4).

There's always some variation between boats, so I would double-check these measurements against the rudder you have.

[Theis]

Pete:

How many rods do you show through your rudder (Other than the screws mounting the rudder to the shaft? Do the drawings reflect the actual number?

[Jim Wiles]

CPete,
Thanks so much for taking your time to measure your extra rudder! These measurements will be worth a million bucks to me since I can lay in supplies and make sure that I order enough of everything so that when I bring #391 back to my home in the fall of 2004 I can get on with the job. I can already have the blade finished, and the 1" bronze ready to cut to the exact length, etc.
Best wishes and Happy Holidays!
Jim

[Bogle]

The three-piece (plank) design is what commander #92 has. That will be my scheme for replacement this winter, duplicating as closely as possible the original design.

I have inquired to the wooden boat forum regarding wood species, and Honduran mahogany seems to be the best compromise between the original "phillipine" (a little less expensive than Hoduran) and the best material for a rudder, east indian teak.

The thread is at:

http://media5.hypernet.com/cgi-bin/U...c;f=1;t=008475

More after the new year when I get started...

[Theis]

Last year, as I recall, there was interesting informationon this forum submitted by Mike Goodwin about woods related to cockpit coamings, which included an explanation of the difference between Honduran and Phillipine Mahogany (the latter being not a mahogany, but a genre of cedar, as I recall). It might be interesting for you review that (Dec. 2, 2002)

[commanderpete]

Theis,

Those 5 rods go right through both pieces of wood and through the shaft. A rough outline of their placement is below.

Seems a robust construction method. However, as ebb noted, this style doesn't have a tapered trailing edge. You would need to create that somehow if you wanted it.

I came across an article on rudders. A bit too technical for me

http://www.boat-links.com/foils.html

[Theis]

I have to tell you why your information is so interesting. You would think that Pearson had a routine - a system for making their rudders, but it seems to wander all over the lot.

When I mentioned to Bill that there were rods through Solsken's rudder, he asserted, unequivocally, that Pearson never put rods through their rudders and that had to have been done by one of the previous owners (in my case there was only one previous owner, and he didn't do it). So the issue was on the table, and I opined that folding my tent to better authority was the appropriate response.

So now you come with five rods - and the rods go right through the shaft (my rods do not - and there are only three of them as I recall).

I do have three bolts (I think that is correct) in addition to the rods that extend through the shaft into the rudder, and one screw - each extending to about the middle of the rudder (the nut and washer are embedded in a cut out in the wood rudder.

Like others, my original rudder was made of three pieces - which, over time separated. The outside piece was largely held on by the rods because the bolts did not extend into it.

So - the point is that there appears to have been considerable variation in the way these rudders were assembled. For reference, Solsken in #82 built at the end of 1982 - or so I have been led to believe.

[Bogle]

Pete's rudder diagrams are of his REPLACEMENT rudder, not an original. Correct me if I am wrong. They did not follow the original design in number of planks or fastener types and locations. See the diagram in the manual which does not show the drift pins.

The drift pins (rods) are a common feature of these traditional plank rudders. Mine has three and they do not go through the rudder shaft.

[commanderpete]

The drawing in the Manual shows the original rudder was attached with (3) 6" bolts and (3) 5" wood screws. It also says the rudder is "solid mahogany."

I've only seen rudders that had the three planks. The original rudder on my Commander 200 looks about the same as Dave Bogle's. Here's a pic, taken just after haulout.

[commanderpete]

You see those horizontal slats, which don't appear on some rudders, like Kent's

[Theis]

I was looking for those horizontal slats, but assume CPete took the picture at an angle, and, if rotated to be viewed properly, the bow facing toward the sky, the spaces between the slats would be horizontal. I assume CPete that such is what you were referring to when referring to horizontal slats. Right?

My original rudder looked similar to CPete's, and, like it, the slats had separated/shrunk (not good). The bolts went through to the center of the center slat as I recall. The propeller insert (for the outboard version) was held in place by a couple small angular screws from the wood rudder to the wood insert.

It might be interesting to associate a year with the boats we are referencing so we could get a take on if, and the extent to which the design changed over time.

[Jim Wiles]

As I have said in previous rudder related threads, I'm getting all of the materials together so that I can really get to work next fall and build a new rudder.
Things a really falling into place pretty well. I was really considering "Jamestown Distributors" for the 1" rod except that it is silicone bronze. This past week I found another supplier near Chicago called "Copper and Brass Sales" in Schaumburg, Il. phone: 800-926-2600. They have true "464 Naval Bronze rod" and it is $50.00 cheaper than J.D. for the approx. 6 foot length that we need for a Ariel shaft, or $148.43 for 6 foot of 1". They also have many other rod sizes and I think I'm going to use their 5/16 " naval rod from blind holes through the planks. Just thought I'd pass this info along.
__________________________________________________ __
I still am looking for companies which sell Hondouran Mahogany if anyone knows of any. Jim_______________________________________________ ___

[Theis]

Jim:

There are two places you might want to look at. One is Kettle Morain Hardwoods - with a place on 94 just south of Milwaukee (Racine area) and one just north of Milwaukee. The town is Caledonia and the phone is 835-9212 (Don't know the area code but it might be 262). They are very helpful - good people - and they like sailors.

There is/was a place in Bedford Park, just south of Chicago, that handles specialty woods. I used to deal with them but now have found the first place, closer to home.

[Greg]

Jim,

You might try Pekin Hardwoods S. Main St in Bloomington. Their yard is just south of Pekin, but they have the retail store in Bloomington and can get most anything you need. Nice folks there...just don't ask for marine ply, unless you like blank looks.

[ebb]

Probably should keep my mouth shut.

Naval bronze is naval brass and can have as much as 40% zinc to 59% copper, with a bit of tin as a binder. Better ask for the alloy numbers from the supplier. And I would get the alloys closer together on the galvanic scale viz the shoe/shaft and aft thruhulls. But then that's just my opinion.