Minimum Width rudder can be built yet remain

If you want to lose drag, lose planform area, but as someone else said, respect the ratios of areas between the dagger and rudder.
Rudders are ultimately limited by needing to go to max cl out of tacks or dodgy manoeuvres or keeping control on windy days.
AC foil designer I know said that if you're going below 12% thickness you're better off losing chord (and planform area /WSA and thus friction) whilst keeping a more stall tolerant shape.

You can reach structural limits too. I just built a rudder that can take a tonne of force. 19mm thick, of which ~2mm HM unis in 50mm strips staggered out. Carbon or HD foam shear web. Weighs little more than a kilo.

ou could, if building solid carbon, go to maybe 6 or 8mm thick, but unless it literally is the chord of a windsurf fin, it'll have sh*t stall performance.

Originally posted by I luv Wight < up on its ear>You see the good guys sailing like that? ( unless it's a scow )The further down the fleet, the more tippy uppy they are.I've made very long, very thin rudders...  seems faster for the faster sailors.

Good guys? Hey it's me we're talking about, when it's windy on it's ear is where I live..

I used to have a nightmare with that RS500 with the rudder not functioning out of skewed up tacks or gybes..

Long and deep could work and I have an old wooden storm foil from a windsurfer that might fit in the stock. I've seen Merlin rudders with an extra trailing tip which I assumed was to counter steerage issues if up on their ears, but then, that wouldn't work would it, I wonder what they're for.

Makes you think the ideal shape might be a scimitar reversed..



Edited by iGRF - 02 Feb 16 at 10:40pm