Getting there - 60% done!

Jami

frankly, I think the idea of twist is something we have inherited from the Bermuda sloops. On these the foresail pre-bends the airstream more in the lower half than in the upper, so it makes sense to have twist in the mainsail. If the sloop is of the partial jib type, like the Nordic Folkboat, more twist is needed to avoid stalling the top section of the main.

On my sloop JRs, I have found that next to no twist is best. That is when the telltales at the leech of all the panels are easy to make fly (photo below). However, on fully fanned junkrigs, I understand that controlled twist is used to induce camber in the otherwise flat sails, but that is another story.

Arne

What twist?

I don't think there is any twist in my sail (with 2-part sheeting) and one of the things I rejoiced in when making the Amiina-type SJR was that the jibs (and mains) are all identical. Nice and simple. There might be some point in sequentially reducing camber, perhaps - though everything comes at a cost - but I would never have thought of reducing sheeting angle.

Another thing, if you reduce the sheeting angle of the upper jibs, how are you going to reduce the sheeting angle of their associated main panels? I must be missing something here.

I am envious of your sewing ability.

Thanks,
but what I've learned so far (with this one being my third junk sail) is that the difficult work happens before the sewing. It includes the sailplan and especially the magic of turning the 2D cloth into a cambered 3D sail.

And fortunately this mastery has been done for the rest of us by people like Arne, Slieve, David and others.

Moving on nicely. The first jiblet and main soon made, and I’ll be able to slide them to batten tubes and check everything is as it should.

I’m using 45 deg shelf foot method for both the jiblets and the mains. I’ll also continue with the hinge method, like I did on my previous sails. Despite the work, I like the modular sail for several reasons.

11% camber and 12% sheeting angle for the jiblets, 8% camber for the mains. These are for the lowest 2-3 panels and will be less after that.