Re: [Cal_Boats] Re: Sail design

Allen: I'd like to know a bit of what your sailmaker explained if you don't mind. I have learned quite a bit from this list, and since I will be looking for a set of sails, I certainly would benefit from what you and the rest of the group coul comment on the subject. Speaking of sails, I have what looks to be a 150 headsail for a Cal 33. I want to sell it as the luff is about 12" too long, about the distance taken by the furler. I thought of getting it cut to fit, but the 130 is probably a better fit for the trades in the Caribbean. The 150 looks to be in pretty decent shape, if anyone is interested, I can send detailed photos. Jeff Cal 33 On Jan 8, 2010, at 8:18 PM, Allen Edwards <al… [at] PaloAltoPhoto.com> wrote: Nevermind, the sailmaker explained it. Sorry to bother the list. Allen On Fri, Jan 8, 2010 at 1:02 PM, Allen Edwards <al… [at] gmail.com> wrote: There are a lot of smart people on this list so maybe someone can help me here. I just spent most of the last hour on Google trying to figure this out but all it got me was the definition of camber. I am trying to specify a new sail and trying to model it with a program called SailCut CAD. No matter about that. I asked the sailmaker what the parameters of the sail would be. I asked about entry and exit angles and draft for three levels, and sail twist. Below is what I got back. Anyone know how to translate between the two? The only thing I have been able to figure out is that Camber is another word for draft. I expected three draft numbers and one twist number, but that isn't what I got. Camber 11.8 Twist Lower 18.0 Mid 22.7 3/4 30.6 Allen

Sure, this is what he said: "The twist numbers work like this. if you were to have a straight plane from the headstay to the mast, the twist numbers are degree off of that plane to the leech of the sail. measured from the headstay." The sailcut CAD wants the slightly different numbers. If you lay out a sail cross section on a line from luff to leech then it wants the angle the leading edge is relative to that line, same with the trailing edge. Draft and camber are the same thing. SailcutCAD has a twist input that is like the twist we all know and live but I don't yet know how it is measured. Quantum sails are very flat on the trailing edge. I think they say this is fast. I use them because the sails guy is wonderful. If anyone is in SF area, ask for Don and tell him I sent you so he is even more inclined to give me great service. Please let me know if I can help in any way. I am spending way too much time specifying this sail and I am just getting started. If you are getting a 130, make sure it clears the spreaders. A fraction less area gives you way more pointing ability. Allen On Fri, Jan 8, 2010 at 4:53 PM, Jeff <je… [at] yahoo.com> wrote: > > > Allen: > > I'd like to know a bit of what your sailmaker explained if you don't mind. > > I have learned quite a bit from this list, and since I will be looking for > a set of sails, I certainly would benefit from what you and the rest of the > group coul comment on the subject. > > Speaking of sails, I have what looks to be a 150 headsail for a Cal 33. I > want to sell it as the luff is about 12" too long, about the distance taken > by the furler. I thought of getting it cut to fit, but the 130 is probably a > better fit for the trades in the Caribbean. > > The 150 looks to be in pretty decent shape, if anyone is interested, I can > send detailed photos. > > Jeff Cal 33 > > > > Sent from my iPhone > > On Jan 8, 2010, at 8:18 PM, Allen Edwards <al… [at] PaloAltoPhoto.com> > wrote: > > > > Nevermind, the sailmaker explained it. Sorry to bother the list. > > Allen > > > On Fri, Jan 8, 2010 at 1:02 PM, Allen Edwards <allen.p.edwards@<al… [at] gmail.com> > gmail.com> wrote: > >> There are a lot of smart people on this list so maybe someone can help >> me here. I just spent most of the last hour on Google trying to >> figure this out but all it got me was the definition of camber. I am >> trying to specify a new sail and trying to model it with a program >> called SailCut CAD. No matter about that. I asked the sailmaker what >> the parameters of the sail would be. I asked about entry and exit >> angles and draft for three levels, and sail twist. Below is what I >> got back. Anyone know how to translate between the two? The only >> thing I have been able to figure out is that Camber is another word >> for draft. I expected three draft numbers and one twist number, but >> that isn't what I got. >> >> Camber 11.8 >> Twist >> Lower 18.0 >> Mid 22.7 >> 3/4 30.6 >> >> >> Allen >> > > > >

Allen: Thanks for the feedback, I'll run some measurements on the 130, I don't recall if it cleared the spreaders, I'll have to check some pics to see of it does. I sent a couple of e mails to the quantum guys, never got a response, maybe if I let them know that I know you.... Jeff, Cal 33