Ron
That sounds about right from my experience, but I like the way the boat works with a slightly smaller headsail _____ From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Ronald B. Frerker Sent: December 2, 2013 7:16 PM To: cnc-list@cnc-list.com Subject: Re: Stus-List 30 MKI weather helm - mast rake The manual for my 30 indicates the rake should be 9in measured at the gooseneck. I have a 1973 vintage. I've sailed in 15kt with gusts and the 160 up and a bubble in half the main, traveler down, with no problems with weather helm until the puffs hit. Granted the rail was almost kissing the water. Something sounds wrong if you're suffering weather helm and I don't believe it's the mast rake. Ron Wild Cheri On Wednesday, November 27, 2013 6:32 PM, Dennis C. <capt...@yahoo.com> wrote: Aaron, It's not a 10" rake, it's a 1 degree rake. Conventional wisdom for C&C's seems to be that a 1 inch rake is optimum. However, that's dependent on lots of factors, namely the condition of the sails. Flat sails result in less weather helm. Note that it's not just the main but can include the genoa as well. A larger genoa, 150-170% overlap, with a deep draft aft or a cupped leech can increase the propensity for weather helm. Yes, it's a balance between center of effort (CE) and center of resistance (CR). The draft of the sails affects CE. The further aft the draft is, the more CE moves aft. The deeper the draft, the more effect it has. So, 1 degree of rake is probably about 7 inches for your boat. I run about 11 inches on Touche' and am contemplating another inch or two more. Multiply your boat's P dimension by the sine of 1 degree or 0.01745. Your P is 34 feet. That gives you 0.5933 feet or 7 inches aft. Drop a plumb from the masthead to the gooseneck. Increasing the length of your forestay will move the masthead aft and increase rake. I seem to believe 1 inch of forestay will move the masthead about 3-4 inches. You can approximate it closely it with the Pythagorean theorem. Go here: http://www.basic-mathematics.com/pythagorean-theorem-calculator.html Assuming the technical info on the C&C website is a plumb mast, we do a bit of math. "C" = your I dimension or 39 feet. "A" will be your J dimension, 13.5 feet. This yields a "B" of 36.6. This will be the new B in our next calculation. Let's add the desired rake, 7 inches to the "old" J to yield a new A of 14.08. Plug that in with the calculated "B" of 36.6 and you get a new C of 39.2. So, you need to increase your I dimension by .2 feet or about 2.5 inches to move the masthead 7 inches. Of course, your mast may not be plumb but you can use the tool above to see where you need to be. Good luck, Dennis C. Touche' 35-1 #83 Mandeville, LA _____ From: Aaron Rouhi <admiralmag...@outlook.com> To: "cnc-list@cnc-list.com" <cnc-list@cnc-list.com> Sent: Wednesday, November 27, 2013 2:14 PM Subject: Re: Stus-List 30 MKI weather helm I never tried a 10" rake. I'll give it shot. I think I have enough tread in my forestay turnbuckle... Thanks guys! Cheers, Aaron R. Admiral Maggie, 1979 C&C 30 MK1 #540 Annapolis, MD _____ From: dwight...@gmail.com To: cnc-list@cnc-list.com Date: Wed, 27 Nov 2013 16:08:37 -0400 Subject: Re: Stus-List 30 MKI weather helm Your thinking seems fine: I just have no experience with forward rake that I can share. I have never tried that but I don't think it would work good upwind.6-10 inches should be good, something else might be the problem _____ From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Aaron Rouhi Sent: November 27, 2013 3:55 PM To: cnc-list@cnc-list.com Subject: Re: Stus-List 30 MKI weather helm Hmmm.... I always thought with more mast rake the Center Of Effort moves further aft which means wind pushing the boat from behind the CLR and as a result weather helm increases so using that logic I raked it forward to move COE forward. Am I wrong? Cheers, Aaron R. Admiral Maggie, 1979 C&C 30 MK1 #540 Annapolis, MD _____ From: f...@postaudio.net Date: Wed, 27 Nov 2013 13:43:13 -0600 To: cnc-list@cnc-list.com Subject: Re: Stus-List 30 MKI weather helm Aaron - Dwight's right, you're going the wrong way! Rake aft about six to eight inches and see what happens. Fred Street -- Minneapolis S/V Oceanis (1979 C&C Landfall 38) -- on the hard in Bayfield, WI :^( On Nov 27, 2013, at 12:52 PM, dwight <dwight...@gmail.com> wrote: What is she like after that change? I am not sure how that would work on a beat.seems unconventional to me.I would try 6 to 10 inches aft Are you talking 10 kts true or apparent wind.is it usual for you have a reef in when most other boats around you don't _____ From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Aaron Rouhi Sent: November 27, 2013 2:20 PM To: cnc-list@cnc-list.com Subject: Re: Stus-List 30 MKI weather helm It's raked about an inch forward... It's a recent change I made in an attempt to reduce the weather helm... _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com _____ No virus found in this message. Checked by AVG - www.avg.com <http://www.avg.com/> Version: 2012.0.2247 / Virus Database: 3629/6371 - Release Date: 11/27/13 _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com <http://www.cncphotoalbum.com/> CnC-List@cnc-list.com _______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com <http://www.cncphotoalbum.com/> CnC-List@cnc-list.com _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2247 / Virus Database: 3629/6384 - Release Date: 12/02/13
_______________________________________________ This List is provided by the C&C Photo Album http://www.cncphotoalbum.com CnC-List@cnc-list.com
