T-Foils

[N3291 (Guest)]

Hi
I am thinking about making a T-Foil rudder and was wondering what foil sections and chord lengths are best.
Thanks
Tom

[mutt]

not having built one for a N12 this is just as suggestion - but h105 is the section used on foiling moths so should give good lift. However you might find it difficult to shape due to the concave curve. Naca sections are altogethor easier to shape and give adequate lift I would  suggest under small angles of attack.
To save yourself some trouble you could use a couple of windsurfer skegs - easily obtained second hand as they get knocked about. They have the advantage of being the right size and section but are a little heavily built. I have a couple in my garage that I intend to use in this manner at some point.
www.uk-cherub.org has a how-to on building t-foil rudders.
Mutt
N3486

[Grounded (Guest)]

I don’t know the answer, I do know a couple of things;
-Moths are operating at totally different speeds than 12s, as such their optimum foil designs will be very different from ours.
-You want lift off your T foil, as such your foils are likely to be asymmetric, windsurfer fins are not.
 
There is an awful lot of trial an error to be done here before anyone can speak with any kind of authority.  I’d try to build something where it’s not too difficult to change the wings when you want to try something different.
I’d give Joe a ring, I think he’d be quite prepared to give you the benefit of 5 minutes of his experience which is probably the best you’re going to get.

[darebarry]

I have just fitted a T-Foil to 3521. This is a standard foil and stock made by Composite Craft. Used it a Salcombe for the first time and it seemed to work well, big advantage it just fits on normal rudder fittings. In reply to your question who knows that is best, it is the time to play and try, but it does look good.
dare 

[JohnMurrell]

Tom,
 
One of the main things to bear in mind is where you sail............
 
T-foils are great for clearing weed but as Salcombe is a Site of Special Scientific Interest the removal of the underwater vegitation might be frowned on!
 
On a different tack, has anyone given any thought to a Hydrodynamic design for a weed stick? Could be the next bit of go fast gear!!!

[Mikey C (Guest)]

-Moths are operating at totally different speeds than 12s, as such their optimum foil designs will be verydifferent from ours.
You'd have thought, but all the heavy lifting done by Moth foils is at the sort of speed you'd be looking at getting a T foil working on a 12. That said, the H105 wasn't very good at this and was more of a high speed foil.


-You want lift off your T foil, as such your foils are likely to be asymmetric, windsurfer fins are not.
Totally agree - been there and done it for several people who have supplied me with skegs to fit to their rudders. They do a very poor job at lifting.