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T O P I C R E V I E W
Sublime
Posted - 07/20/2018 : 13:47:49 “A 50 lb push should deflect the upper by 1 inch” is pretty useless for me. If anyone has converted this to a measurement on a loos gauge, I’d be highly appreciative!
16 L A T E S T R E P L I E S (Newest First)
Steve Milby
Posted - 05/11/2019 : 01:26:16
quote:Originally posted by islander
Steve I think you mean tensioning the luff of the sail too much puts a strain on the swivel and would impede it's ability to rotate. The RF only rotates on the forstay so forstay tension really has no effect on it. Also the majority of the weight of a RF is supported by the drum.
You're right. I forgot that.
islander
Posted - 05/10/2019 : 13:26:32 Steve I think you mean tensioning the luff of the sail too much puts a strain on the swivel and would impede it's ability to rotate. The RF only rotates on the forstay so forstay tension really has no effect on it. Also the majority of the weight of a RF is supported by the drum.
AlMo
Posted - 05/10/2019 : 09:05:42 Great info, Steve!!! Think you hit the nail on the head in many respects, and I'm on the way to the boatyard to get that thing tuned and in the water today. I will take your advice on the forestay tension impeding furler smoothness, as well as putting a small bit of aft rake to aid weather helm. Thank you for the thoughtful and helpful reply!
Steve Milby
Posted - 05/09/2019 : 13:39:10
quote:Originally posted by AlMo
Anybody have advice on using a roller furler (adds 30-35 lbs to the forestay) and a good bit of wind drag, and how that would affect tuning recommendations?
There is very little difference between tuning a rig with or without a furler. Here's an answer that I gave to that question previously:
"The general purposes of rig tuning are: (1) To firm up the rig so that it supports the sails so that you can shape the sails correctly. (If, for example, the forestay is too loose, the sail can't be depowered enough in strong winds, and the sail won't present a clean entry to the wind, enabling the boat to point well.) (2) To adjust the center of effort of the sailplan so that the amount of force exerted on the sails forward of the center of lateral resistance are balanced properly against the amount of force exerted on the sails aft of the center of lateral resistance, so that the boat has just the ideal amount of weather helm without causing the rudder to produce excess drag to hold the boat on course.
Those goals of rig tuning are exactly the same, regardless of whether or not the boat has a furler, or whether it has a backstay adjuster.
The only difference in tuning a rig with a furler is that you should leave the forestay tension about 1/2 turn of the turnbuckle looser. The reason is that, if the forestay is too taut, it can impede the ability of the furler to turn freely, especially if it doesn't have ball bearings, preventing it from working smoothly and wearing it out prematurely. The forestay should be as taut as it can be while still allowing the furler to turn freely."
quote:A new jib plus a fairly old main would suggest to me based on reading http://www.catalina-capri-25s.org/tech/tech25/snkmast.asp that I would want forward rake, just wondering how much the furler luff weight may affect the amount of forward rake I would start with.
The mast should never have a forward rake on any boat. If it is raked at all, it should be raked aft slightly. If a mast is raked forward, the boat will have lee helm. By tilting it aft slightly, you create weather helm. The farther aft you tilt it, the more weather helm.
Too much weather helm is bad. It pulls so hard at the tiller that you become arm-weary just to hold the boat on course. Too little is equally bad. If you let go of the tiller, the boat will keep sailing on an erratic course. With the correct amount of weather helm, if you let go of the tiller, the boat will come into the wind, the sails will luff, and the boat will stop.
quote: The article represents mast tuning as an iterative, "feel-based" art, and I get that, just looking for any advice from C25 owners that do their own tuning. Thanks!
That impression is understandable, but not entirely correct. The rig is the structure on which your sails are hung. The way that it is adjusted has a lot to do with the way your sails are shaped. It also has a lot to do with the way your entire sailplan is balanced. Those matters have nothing to do with "feel." They relate to aerodynamics. Where "feel" comes into play is in determining the amount of weather helm that is comfortable to you and that accomplishes your goals for the boat.
AlMo
Posted - 05/09/2019 : 10:35:58 Anybody have advice on using a roller furler (adds 30-35 lbs to the forestay) and a good bit of wind drag, and how that would affect tuning recommendations? A new jib plus a fairly old main would suggest to me based on reading http://www.catalina-capri-25s.org/tech/tech25/snkmast.asp that I would want forward rake, just wondering how much the furler luff weight may affect the amount of forward rake I would start with. The article represents mast tuning as an iterative, "feel-based" art, and I get that, just looking for any advice from C25 owners that do their own tuning. Thanks!
jerlim
Posted - 08/22/2018 : 18:08:26 It is not properly sized for the forestay, backstay and the upper shrouds, but I've found that the gauge is most useful in determining if opposing cables are of the same (or nearly) tension.
islander
Posted - 08/22/2018 : 04:47:35 I have the Loose guages and they are helpful in letting you know precisely how much tension you have on the wires. Plucking or pushing is just a feel and can be very different between different people.They also let you know that the tension is the same on both sides and that you haven't over tensioned any wires that is easy to do. Anyway I used the method suggested on the forum and used the guages to check and adjust.
Sublime
Posted - 08/21/2018 : 21:28:50
quote:Originally posted by Steve Milby
You can find articles on how to tune your rig in our tech tips section. A loos gauge doesn't tell you how to tune the rig. As JB said, it only helps you make the tensions uniform and consistent.
Also, tuning the rig makes the rig erect, straight and resistant to the loads imposed on it, and makes the boat perform equally well on either tack. It balances the CE of the sails against the CLR of the keel. An imbalance causes a heavy helm or inadequate weather helm.
Tuning the rig has only an incidental effect on sail shape. If you'll describe the problems you're having with sail shape, we might be able to offer some suggestions.
Thanks for the explanation.
I'm aware that a loos gauge doesn't tell you how to tune your rig.
My experience has been that the rigging can have quite a profound effect on sail shape.
I was simply pulling some bagginess out of my sail and it looks much better after making some adjustments. With the loos gauge, I know I'm within a recommended working load for the shrouds which makes me sleep good. I tend to like a tighter rig but I don't want to go by plucking sounds and such. I generally set it to a starting point, see how it sails. The loos gauge lets me make accurate and consistent adjustments if I feel it needs it.
All I was looking for was a consensus on an actual number for the range of tension most are having luck with. Because I'm lazy.
Steve Milby
Posted - 07/23/2018 : 10:43:29 You can find articles on how to tune your rig in our tech tips section. A loos gauge doesn't tell you how to tune the rig. As JB said, it only helps you make the tensions uniform and consistent.
Also, tuning the rig makes the rig erect, straight and resistant to the loads imposed on it, and makes the boat perform equally well on either tack. It balances the CE of the sails against the CLR of the keel. An imbalance causes a heavy helm or inadequate weather helm.
Tuning the rig has only an incidental effect on sail shape. If you'll describe the problems you're having with sail shape, we might be able to offer some suggestions.
JB
Posted - 07/23/2018 : 08:28:00 We only use the gauge to even up the tension after setting it while sailing on various points of sail. When we take the mast down we mark the toggles with tape so that adjustments are minor. We try to run as loose a possible without too much slack on the lee side.
Good info! I'm struggling with some sail shape and I think it's the tuning on my rig. This is my first go with a masthead rig so I'm learning.
Sublime
Posted - 07/22/2018 : 00:05:27
quote:Originally posted by jduck00
Yes, I keep two on the boat for mast tuning. There's not a single gauge that I know of that will get all of the rigging on our boats. I pull mine down to about 15% using the guide in the tech tips. Always works out nicely. http://www.catalina-capri-25s.org/tech/tech25/snkmast.asp
So that's around 600 lbs?
I've got two loos gauges. One is for smaller rigging. The other is for larger rigging lol! So I'm trying to figure out what reading would be on what I have.
Derek Crawford
Posted - 07/21/2018 : 07:52:49 I guess that I'm the odd one here, I used just the small Loos gauge on all the shrouds without a problem. I kept a very loose rig and did not bother to convert the front gauge readings to the poundage on the back. I kept the aft lowers at 20, the uppers at 30 and the forward lowers at 25. Probably too loose for most but great for a hard core racer...
jduck00
Posted - 07/21/2018 : 07:01:47 Yes, I keep two on the boat for mast tuning. There's not a single gauge that I know of that will get all of the rigging on our boats. I pull mine down to about 15% using the guide in the tech tips. Always works out nicely. http://www.catalina-capri-25s.org/tech/tech25/snkmast.asp
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.