mainsail attachment methods

I’ve been searching the forum and came with this:

the pics aren’t showing up anymore…

I also read Lester’s page and remember a post from Greg V.

What are your thoughts? Keep it simple?

I think the shape of the mast makes more of a difference thanthe way you attach the sail to the aft edge if it. A round mast has worse flow around it than an airfoil-shaped one.

forgot to add that it is for an IOM!

The luff slot idea is interesting , Lester mentions wind tunnel data showing some improvement , seems to be acting like a leading edge Flap. I’m going to try it on my next suit of sails.

An air foil shaped mast works best if it can rotate into the air flow , round mast will be consistent through all angles of attack.

and if it is class legal! Be sure and check before you decide.

not much info so I did it “my” way…or like many others do!

Made a gap of 4mm.