naca 0014 foil rudder

[awamd]

i have been reading the discussion of the naca 0014 rudder.  Why 0014?  Why not 0012 or 0016 etc.?  is there an article or discussion on the airfoil rudder design and why the 0014 is best for the cp16/
awa

[roland cobine]

   talk to doug 142 or john j----they both made excellent rudders.

[DOUG142]

Aye! Swabbie,
I choose the 0014 as an experiment.  Nobody said it is the best for the cp16.  It works great is all I can say.  Idasailor rudders are 0012 I do believe.  I didn't want mine to be the same as theirs....so therefore the NACA 0014.

Try different ones and see what you think...
Any within the range of 0012 to 0016 is alot better than the stock FLAT plate rudder.

Works for me... see pics at my image gallery 

Just got back tonight from sailing with another CP-16 and blew circles around and around him....
the rudder............... maybe.

The Naca 0014 works and works great is all I can say....try it if you make your own. 
Doug
Summer Escape

[David Olson]

0012 was chosen based on hull speed.

[Bob23]

How do I get the profiles for the NACA 0014 or 0012? I plan on building my own foil rudder for my 1985 23/2 "Koinonia". Thanks, Cap'ts!
Bob23

[DOUG142]

Bob,,
You can get the foil design at compufoil 3d, or any of the air foil design programs.  the 3D one is what I used on my CP 16.  My NACA foiled rudder.
You can see it and some of  the building of it on my website at www dot martindalewoodworking dot com      Scroll down to the tab marked Compac 16 and double click on it.

I am currently working on a foam cored rudder with "glass" covering.  Using that Pink closed cell foam from one of the box home supply stores.  Should be ALOT easier to shape than using wood. 

Let me know how it goes and if I can help.  Ask away.
Doug
Summer Escape
CP 16

[kchunk]

Bob, you can get the foils at JavaFoil at http://darwin.wcupa.edu/webapps/javafoil/. I was going to make my own until Joel from Idasailor emailed me an offer I couldn't refuse. Anyway, I think Doug is on the right track with the foam suggestion. in A&P school, one of the projects we had to to do was make a small section of a composite wing. Here's what I was planning to do with my rudder (and still may do someday):

From Javafoil, print out a 0012 foil using 60 points or so. From this paper foil template, transfer the foil to plywood and make two plywood templates. When you find a foam that's compatible with epoxy, you'll want to shape the foil. What I was going to do was use two pieces of foam about 1'X2' and 2" thick each, tack them together sandwich-style temporarily and then tack the plywood templates on the ends. Then all we did in school was run a hot wire over the template and it cut the foam like butta. Once you have the foam foil, decide whereabout you want your foil to reside relative to your original rudder. Like many have found, if you put some of the foil a little forward of the leading edge of your original rudder it will have a power steering effect. Once you're happy with the location, trace your original rudder on the inside of each foam sandwich half and then carve out an amount equal to half the thickness of the rudder from each half. This will make a little pocket in your foam sandwich equal to the size and thickness of your original rudder. Now complete your rudder sandwich (all this sandwich talk is getting me pretty damn hungry), foam-aluminum rudder-foam. Glue it all together with epoxy or whatever and then glass the whole thing in, sand, fill and fair...should be easy right? I don't know, I've never done it before.

Now, not having done this myself, there are a few caveats:

• The hot wire will have to be strung tight in a fabricated bow of some sort. To make the hot wire hot, a big transformer will work, like the one used on them old, giant Lionel trains. You can dial up the power just till the wire glows.



• Consider some sort of corrosion protection for your original rudder blade (now a spar). It will be permanently encapsulated in your new rudder assembly.



• Closed cell foam will be best but make sure it will be compatible with epoxy and any other glues or materials you'll be using.



• Make sure you use some sort of mechanical attachment securing your foam sandwich with the rudder blade in the middle. Hate to see you go through all this work just to have your foam foil just slip off your blade like a sleeve.



• Lastly, I was thinking about trimming and inch or two off the trailing edge of the stock blade before sandwiching it in the foam. I think it will lead to a stronger assembly. Otherwise the trailing edge of the foam might be too thin and weak. You'll have to figure that one out when you get to that point.
  

I'm sure there are plenty of other gotchas I haven't thought of, but these are just a few considerations I came up with before even trying the job.

It definitely sounds do-able to me!

--Greg

[Brian 1851]

Greg, I am curious of the offer Joel made to you because I was thinking of possibly making a foil rudder.  The cost of 479.00 for the idasailor rudder is a little steep for me but I am longing for more efficiency in this area.  To me the drag is very noticeable.  If you could share this information I would be very interested and appreciative.

[kchunk]

Brian, part of my "arrangement" with Joel was that I would not share the details. The way it was explained to me was he had just one blade left for the CP23, it was an older model, brand new, but just wanted it gone. My understanding is that you can't buy just the blade anymore, you have to buy the whole shebang.

I say go for the home-made rudder. I think it's definitely a DIY project...and you'll be damn proud of yourself when it's done!

[Brian 1851]

Thanks Greg for the information and your fast reply.  I wish I had gotten a foil rudder when they were $200.00.  I will definitely be looking into making one myself somehow with the information on this webcite and a lot of questions.

[Bob23]

Thanks to all for super-prompt responses. I plan on rethinking my plan using wood and thin 1/8" plywood and may make the switch to foam. I'm a woodworker so naturally that's always my starting point. Is there anyone out there who has a spare stock blade for a 23? I don't want to tie up my blade while building the foiled one.
Bob23

[kchunk]

Bob, maybe buy John K's rudder from a 16. All you really need it for is a backbone or spar.

http://cpyoa.geekworkshosting.com/forum/index.php?topic=2483.msg13874#msg13874

--Greg

[hobnob]

I was just talking with Joel today, and what they discontinued is a "direct" replacement foiled rudder.  This unit retains the original cast rudder head.  What they have now, and what I bought from them a couple of years ago, is a longer rudder that's entirely HDPE (the old style was aluminum at the top and HDPE at the bottom).  The new one comes with a stainless rudder head with a gas strut to keep the blade in the water.  Not only have I been very happy with the rudder itself, but Joel is excellent to work with.  These guys are very customer service oriented and seem to LOVE what they do.