Hi Paul, My earlier comment, "if your headstay isn't set properly" inferred "if it is too long or too slack" as the backstay needs something to tension against. Pumping the backstay to 2500# when the headstay is tight will pull the masthead back a few inches and tension the headstay. Doing that with a loose headstay might exceed mast bend design and damage the mast and or the partners.
Answers setting up your rig at the dock can be found in Selden's manual on the subject. That's what I use because it can be done with a simple folding metric ruler. It also explains the theory behind each adjustment. The best tuning is proven by sailing and after many trial and error type adjustments. Keep a log of each measurement, and each change and it's effect on sailing performance after sailing and eventually you will achieve optimum. Dock tuning: http://www.seldenmast.com/files/595-540-E.pdf Sail shape: https://www.uksailmakers.com/accumeasure Chuck, Resolute, C&C 34R, Pasadena, Md > On December 3, 2019 at 9:50 AM Paul via CnC-List <cnc-list@cnc-list.com> > wrote: > > > Brings a good question. How do I know my headstay is set properly? I've > always wondered and never known an answer. How do I know that my main sail > is optimum shape as a result? > > Paul Hood > C&C34 '81 > ------------------------------------ > Message: 6 > Date: Mon, 2 Dec 2019 23:58:18 -0500 (EST) > From: CHARLES SCHEAFFER <cscheaf...@comcast.net> > To: cnc-list@cnc-list.com > Subject: Re: Stus-List C&C 44 Navtec backstay psi > Message-ID: <1743639909.488638.1575349099...@connect.xfinity.com> > Content-Type: text/plain; charset="utf-8" > > I think rule of thumb for hydraulic backstay is 500 to 600# at the dock and > no more than 25% breaking strength maximum when sailing. For my -10 rated > for 10,000#, that's around 2500#. Probably much higher for your larger > backstay. Of course this is moot if your headstay isn't set properly. > Some boats add a 2" toggle in winds under 15 knots to the headstay so the > main can be flattened without over tensioning the genoa. Physics. > > Chuck Scheaffer, Resolute, 1989 C&C 34R > > > > > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray > _______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
