| Re: Measuring Mast Rake
[Re: Jamie]
#79191 07/27/06 11:05 AM 07/27/06 11:05 AM |
Joined: Mar 2006 Posts: 1,246 Orlando, FL tback OP
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Posts: 1,246 Orlando, FL | I'm carrying a lot of mast rake with the trapeze going 6 inches down the back of the transom. The boat feels good with very little weather helm. Holy S%*^t, That seems like alot I did rake one of the rudders more forward to match the other. How much forward of vertical are your rudders?
USA 777
| | | Re: Measuring Mast Rake
[Re: tback]
#79192 07/27/06 01:10 PM 07/27/06 01:10 PM |
Joined: May 2006 Posts: 954 Mumbles Y.C Wales U.K Mark P
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Posts: 954 Mumbles Y.C Wales U.K | Call me old fashioned, or just plain stupid but I measure my mast rake between the bottom of the forestay and top of the bridle. Its very quick and easy to adjust. I also think that the new fat/square top mains don't require as much mast rake as the older designs but again I'm not a sailmaker and have no means to prove this theory. For me I just feel the boat settles in the groove quicker and for longer with minimum rake. MP*MULTIHULLS | | | Re: Measuring Mast Rake
[Re: Mark P]
#79193 07/27/06 03:48 PM 07/27/06 03:48 PM |
Joined: Feb 2004 Posts: 3,528 Looking for a Job, I got credi... scooby_simon Hull Flying, Snow Sliding.... |
Hull Flying, Snow Sliding....
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Posts: 3,528 Looking for a Job, I got credi... | Call me old fashioned, or just plain stupid but I measure my mast rake between the bottom of the forestay and top of the bridle. Its very quick and easy to adjust. I also think that the new fat/square top mains don't require as much mast rake as the older designs but again I'm not a sailmaker and have no means to prove this theory. For me I just feel the boat settles in the groove quicker and for longer with minimum rake. BUT you cannot compare that with anyone else as your wires may be of differing lengths !
F16 - GBR 553 - SOLD I also talk sport here | | | Re: Measuring Mast Rake
[Re: scooby_simon]
#79194 07/27/06 06:12 PM 07/27/06 06:12 PM |
Joined: May 2006 Posts: 954 Mumbles Y.C Wales U.K Mark P
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Posts: 954 Mumbles Y.C Wales U.K | Exactly!!!! We've previously seen that sails can't be made the same. so don't fool yourself neither are hulls, hardware, masts or rigging. I do accept that using the trap wires is the most accurate method due to "blar, blar,blar" but lets be fair we are not Olympic Sailors. I'm sorry I seem like a killjoy but I have yet to be convinced that Club sailors who take moor interest in boat tunning rather than boat handling win races? Where I sail there is a F18 sailor who has digested every F18 tunning/racing guide and he is fast when he's not upside down. MP*MULTIHULLS | | | Re: Measuring Mast Rake
[Re: Mark P]
#79195 07/27/06 06:44 PM 07/27/06 06:44 PM |
Joined: Feb 2004 Posts: 3,528 Looking for a Job, I got credi... scooby_simon Hull Flying, Snow Sliding.... |
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Posts: 3,528 Looking for a Job, I got credi... | Exactly!!!! We've previously seen that sails can't be made the same. so don't fool yourself neither are hulls, hardware, masts or rigging. I do accept that using the trap wires is the most accurate method due to "blar, blar,blar" but lets be fair we are not Olympic Sailors. I'm sorry I seem like a killjoy but I have yet to be convinced that Club sailors who take moor interest in boat tunning rather than boat handling win races? Where I sail there is a F18 sailor who has digested every F18 tunning/racing guide and he is fast when he's not upside down. Boats are built to a LOT higher tolerances as they would not go together otherwise, wires only need to be about right.
F16 - GBR 553 - SOLD I also talk sport here | | | Re: Measuring Mast Rake
[Re: scooby_simon]
#79196 07/27/06 07:22 PM 07/27/06 07:22 PM |
Joined: May 2006 Posts: 954 Mumbles Y.C Wales U.K Mark P
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Posts: 954 Mumbles Y.C Wales U.K | Boats are built to a LOT higher tolerances as they would not go together otherwise, wires only need to be about right. [/quote]
I see what you're getting at but I'm not convinced that the manufactures work to absoulute dead millimeter tolerances day in and day out when it comes to a fairly trivial thing such as a trap or stay wire for a beach cat. MP*MULTIHULLS | | | Re: Measuring Mast Rake
[Re: Mark P]
#79197 07/28/06 03:40 AM 07/28/06 03:40 AM |
Joined: Feb 2004 Posts: 3,528 Looking for a Job, I got credi... scooby_simon Hull Flying, Snow Sliding.... |
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Posts: 3,528 Looking for a Job, I got credi... | Boats are built to a LOT higher tolerances as they would not go together otherwise, wires only need to be about right. I see what you're getting at but I'm not convinced that the manufactures work to absoulute dead millimeter tolerances day in and day out when it comes to a fairly trivial thing such as a trap or stay wire for a beach cat. [/quote] Excatly, so there is no point using these as the actual measuremnet menthod. Where they bi-sect the hull, YES as this is (more) constant as (having measured many boats) the trap lines are just used to provide the sides of the triangle and so need to be lengthened anyway by adding string to get to the bridal point on the hull.
F16 - GBR 553 - SOLD I also talk sport here | | | Re: Measuring Mast Rake
[Re: alutz]
#79199 07/28/06 05:23 AM 07/28/06 05:23 AM |
Joined: Feb 2004 Posts: 3,528 Looking for a Job, I got credi... scooby_simon Hull Flying, Snow Sliding.... |
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Posts: 3,528 Looking for a Job, I got credi... | In the 18HT class, the italians measure the distance between the top and the mainsail track.
They simply pull up a long measurment tape with the mainsail halyard. I assume you mean the traveller on the back beam. This is another valid method, you just need a long tape measure; the "trapeze wire" method can usually be done with a bit of rope and a ruler !
F16 - GBR 553 - SOLD I also talk sport here | | | Re: Measuring Mast Rake
[Re: scooby_simon]
#79200 07/28/06 06:51 AM 07/28/06 06:51 AM |
Joined: Sep 2001 Posts: 267 Switzerland alutz
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Posts: 267 Switzerland | I assume you mean the traveller on the back beam.
Right! This is another valid method, you just need a long tape measure; the "trapeze wire" method can usually be done with a bit of rope and a ruler !
I guess many ways lead to Rom <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" /> | | | Re: Measuring Mast Rake
[Re: tback]
#79201 07/28/06 08:21 AM 07/28/06 08:21 AM |
Joined: Jun 2005 Posts: 55 Wilmette, IL Jamie
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Posts: 55 Wilmette, IL | How much forward of vertical are your rudders?
With a yardstick against the transom and taking a point 23" below the rudder stock, the stock position had the starboard rudder at 1 7/16" forward and the port at 3/4" to 7/8" forward. With the stock settings, I had weather helm even with the short forestay and staymasters at 7-7.5. In two increments, I moved the port to 1 7/16" and at the same time of the last adjustment, moved the forestay down one hole, which took care of the tiller pull. Jamie Blade USA 714 | | | Re: Measuring Mast Rake
[Re: tback]
#79202 07/28/06 04:57 PM 07/28/06 04:57 PM |
Joined: Aug 2004 Posts: 145 Cheshire, UK Simon
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Posts: 145 Cheshire, UK | On the Spitfire we tie a rope to the trap line, pull it tight to the top of a rudder pintle, then take this forward to the foremost point where it will touch the seam on the top of the same hull. This point is measured backwards from the bridle tang. Recommended setting at 10-15 inches.
Now, I have a question - I have set my boat up the same every time since I got it 2 years ago, based on the same holes on the sidestays and then applying rig tension using the forestay. I figured if I set the boat the same all the time I could focus on sailing (rather than tuning) skills. This setting has been successful for me at club level.
Imagine my surprise then when I got home from the Spitfire Europeans, to find that rather than having somewhere between 10 and 15 inches, I had 0 / zero / none / nada / no rake whatsover by this measure. So I changed it to midway between 10 and 15 and guess what - I am convinced we were slower, actually coming second in 2 races for the first time this series!
What is going on?
Cheers
Simon Shadow 067 | | | Re: Measuring Mast Rake
[Re: Simon]
#79203 07/28/06 08:15 PM 07/28/06 08:15 PM |
Joined: Mar 2006 Posts: 1,246 Orlando, FL tback OP
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Posts: 1,246 Orlando, FL | Seems to me if you rake your mast forward ... you'd have more trap line to extend back to your rudder pintle ... and consequently more trap line (and less distance to cover) to extend forward towards your bridle tang.
USA 777
| | | Re: Measuring Mast Rake
[Re: bobcat]
#79209 08/27/06 12:01 PM 08/27/06 12:01 PM | Anonymous
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Do you still have the logo you sent me that says "If it's not a Cat it's a Dog" with the bobcat with the red eyes? If so sent it to me again. Computer crashed and I lost it.
Doug Snell dsnell4 at houston dot rr dot com | | | Re: Measuring Mast Rake
[Re: JJD]
#79210 08/27/06 03:06 PM 08/27/06 03:06 PM |
Joined: Jun 2001 Posts: 9,582 North-West Europe Wouter
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Posts: 9,582 North-West Europe | It is always easy to lengthen your sidestays. Just put a shackle there (on both sides !) It is best to have some safety margin with the staymasters. Adding two shackles will allow you that. Don't worry about the forces on the sides stays these are low enough to handled by any normal sized shackle. Started at top centerline of hull in line with bridle tang. Took this reference back to where I could touch top centerline of hull near transom. That turned out to be almost exactly 3 inches forward of the transom or about 2 inches aft of the edge of the inspection hatch ring. Does this sound reasonable?
Sounds a reasonable starting point to me. Try it in that position and see how it sails/feels Wouter
Wouter Hijink Formula 16 NED 243 (one-off; homebuild) The Netherlands
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