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rig tuning suggestions
I'm consistently a kt. slower on the port tack than the starboard and
it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. |
rig tuning suggestions
On Thu, 23 Jul 2009 16:51:43 -0500, "mr.b" wrote:
I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. Buy a Loos Gauge. |
rig tuning suggestions
"mr.b" wrote in message
m... I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. If you really expect any decent advice how about providing the following: 1) Make and size of boat include LWL 2) How are you measuring speed through the water? (GPS or submersed rotor?) 3) Angle of heel on port tack 4) Angle of heel on starboard tack 5) What kind of keel does the boat have? 6) Inboard or outboard motor? 7) if inboard is the prop shaft on the centerline? 8) how are you determining the apparent wind angle? Wilbur Hubbard |
rig tuning suggestions
"mr.b" wrote in message
m... I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. Are you sure it's a rigging issue, beyond what you've stated toward the end? Did you notice or not notice this prior to the new rigging? Here's a tuning guide for manually tuning a C&C.. not sure what boat you have. http://www.cncphotoalbum.com/doityou...ing/tuning.htm -- "j" ganz @@ www.sailnow.com |
rig tuning suggestions
Get this document:
http://seldenmast.com/frameset.cfm?i...dnum=334078021 Choose the English version. If the performance of your boat is indeed asymmetrical, something not rig related might be afoot. Your keel (or rudder) could be out of line. Cheers, GM I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. |
rig tuning suggestions
mr.b wrote:
I'm consistently a kt. slower on the port tack than the starboard ... On both tacks the inner shrouds flop loosely... I'm looking for tuning hints here. Tighten the rigging and scrub the portside hull? Brian W |
rig tuning suggestions
brian whatcott wrote:
mr.b wrote: I'm consistently a kt. slower on the port tack than the starboard ... On both tacks the inner shrouds flop loosely... I'm looking for tuning hints here. Tighten the rigging and scrub the portside hull? Brian W That's a winner if the boat is on a marina berth, not a swinging mooring. The side that gets the sun fouls worse . . . -- Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED) ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk [at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL: |
rig tuning suggestions
mr.b wrote:
I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. How are you determining your speed? GPS? Is there any current? |
rig tuning suggestions
On Thu, 23 Jul 2009 18:14:57 -0700, Jim wrote:
How are you determining your speed? GPS? Is there any current? knotmeter cross-referenced to gps, while current can set up, it's not relevant to the problem I'm experiencing because I'm can be in the current on both tacks |
rig tuning suggestions
On Fri, 24 Jul 2009 01:54:27 +0100, IanM wrote:
brian whatcott wrote: mr.b wrote: I'm consistently a kt. slower on the port tack than the starboard ... On both tacks the inner shrouds flop loosely... I'm looking for tuning hints here. Tighten the rigging and scrub the portside hull? Brian W good one! That's a winner if the boat is on a marina berth, not a swinging mooring. The side that gets the sun fouls worse . . . naw it's not...I'm berthed in 18ft of crystal clear fresh water |
rig tuning suggestions
On Thu, 23 Jul 2009 15:48:37 -0700, Capt. JG wrote:
Are you sure it's a rigging issue, beyond what you've stated toward the end? Did you notice or not notice this prior to the new rigging? truthfully no, I don't know for a fact that it is a rigging issue and in fact I did notice this prior to the new rigging. I replaced the rigging because it may have been the original gear on the 40 year old boat. We got a large set of invoices for work done when we bought the boat in 2000, but no record of the standing rigging ever having been replaced. Another poster mentioned keel/rudder alignment. Unless the boat came out of the mold wrong, and I don't think it did because this assymetry has only been noticed for two seasons, I will look closer at the rudder when it comes out in the fall if I can't resolve this by tweaking the rigging. Here's a tuning guide for manually tuning a C&C.. not sure what boat you have. http://www.cncphotoalbum.com/doityou...ing/tuning.htm close enough, mine is a 1966 Hinterholler HR 28 thanks |
rig tuning suggestions
On Thu, 23 Jul 2009 16:51:43 -0500, "mr.b" wrote:
I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. If the rig tuning is off it should show up as a difference in sail shape. Does the main seem fuller or flatter from one tack to the other? How about head stay sag? Are the jib leads in exactly the same position? Have you tried adjusting them separately? Is the jib luff the same distance off the spreaders on both tacks? Many paddle wheel knot meters read differently on opposite tacks. When I was working with high tech instrumentation on my old Cal-34 we ended up installing port and starboard paddle wheels with a switch box which I had to remember when tacking. It sounds like your boat is actually handling differently however, not just a speed difference. If all else fails try to get an experienced rigger and/or sailmaker to go out with you. |
rig tuning suggestions
On Thu, 23 Jul 2009 18:52:18 -0400, gmackey wrote:
Get this document: http://seldenmast.com/frameset.cfm?i...dnum=334078021 Choose the English version. If the performance of your boat is indeed asymmetrical, something not rig related might be afoot. Your keel (or rudder) could be out of line. thanks, a good read |
rig tuning suggestions
On Thu, 23 Jul 2009 22:26:23 -0400, Wayne.B
wrote: Is the jib luff the same distance off the spreaders on both tacks? Correction, make that jib leech (the trailing edge). |
rig tuning suggestions
"mr.b" wrote in message
m... On Thu, 23 Jul 2009 15:48:37 -0700, Capt. JG wrote: Are you sure it's a rigging issue, beyond what you've stated toward the end? Did you notice or not notice this prior to the new rigging? truthfully no, I don't know for a fact that it is a rigging issue and in fact I did notice this prior to the new rigging. I replaced the rigging because it may have been the original gear on the 40 year old boat. We got a large set of invoices for work done when we bought the boat in 2000, but no record of the standing rigging ever having been replaced. Another poster mentioned keel/rudder alignment. Unless the boat came out of the mold wrong, and I don't think it did because this assymetry has only been noticed for two seasons, I will look closer at the rudder when it comes out in the fall if I can't resolve this by tweaking the rigging. Here's a tuning guide for manually tuning a C&C.. not sure what boat you have. http://www.cncphotoalbum.com/doityou...ing/tuning.htm close enough, mine is a 1966 Hinterholler HR 28 thanks Good move about replacing the rigging... I seriously doubt it's an alignment issue. It may just be the nature of the boat. You'll never have a boat that behaves exactly the same on opposite tacks. I've noticed this on many different boats, including my boat, although I've never worried about it all that much. It was professionally tuned. If I have a full water tank (port side), then I can see a slight lean when it sits at the dock. I usually leave it about 1/2 to 3/4 full, which seems to work. Even, for example, and inch off on the traveller center would make a difference. -- "j" ganz @@ www.sailnow.com |
rig tuning suggestions
On Thu, 23 Jul 2009 22:26:23 -0400, Wayne.B wrote:
On Thu, 23 Jul 2009 16:51:43 -0500, "mr.b" wrote: I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. If the rig tuning is off it should show up as a difference in sail shape. Does the main seem fuller or flatter from one tack to the other? no appreciable difference that I can see How about head stay sag? as I said, it sags probably 5 inches anyway off-centre. This can't be right. I guess my biggest concern is over-tightening the shrouds and stays. The seldén.com reference offered by another poster shows tightening turnbuckles a 3-4 mm. past hand tight will have your shrouds at 15% of their breaking strength which they recommend as correct. I think I've got 10mm past had tight already and the rig seems to me to be way loose, at least on the one tack. Another poster recommends a Loos gauge. Perhaps a useful tool. Are the jib leads in exactly the same position? leads are same size, same brand, same position on their tracks Have you tried adjusting them separately? Yes, but there is no apparent difference in jib shape or position -it's brand new i.e., 4 hrs of sail time. Is the jib "luff" - leech the same distance off the spreaders on both tacks? yes, the clew on this #3 just reaches the spreaders so it's very easy to judge Many paddle wheel knot meters read differently on opposite tacks. now this is something I'm going to have a closer look at as well. When I was working with high tech instrumentation on my old Cal-34 we ended up installing port and starboard paddle wheels with a switch box which I had to remember when tacking. It sounds like your boat is actually handling differently however, not just a speed difference. If all else fails try to get an experienced rigger and/or sailmaker to go out with you. thanks for the questions, it helps focus the mind. I've got some guys on the dock who've been there and back. If I can't get this sorted out in the next day or two, I'll ask for help. Cheers |
rig tuning suggestions
wrote in message ... On Fri, 24 Jul 2009 07:21:28 -0500, "mr.b" wrote: On Thu, 23 Jul 2009 22:26:23 -0400, Wayne.B wrote: On Thu, 23 Jul 2009 16:51:43 -0500, "mr.b" wrote: I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. If the rig tuning is off it should show up as a difference in sail shape. Does the main seem fuller or flatter from one tack to the other? no appreciable difference that I can see How about head stay sag? as I said, it sags probably 5 inches anyway off-centre. This can't be right. I guess my biggest concern is over-tightening the shrouds and stays. The seldén.com reference offered by another poster shows tightening turnbuckles a 3-4 mm. past hand tight will have your shrouds at 15% of their breaking strength which they recommend as correct. I think I've got 10mm past had tight already and the rig seems to me to be way loose, at least on the one tack. Another poster recommends a Loos gauge. Perhaps a useful tool. Are the jib leads in exactly the same position? leads are same size, same brand, same position on their tracks Have you tried adjusting them separately? Yes, but there is no apparent difference in jib shape or position -it's brand new i.e., 4 hrs of sail time. Is the jib "luff" - leech the same distance off the spreaders on both tacks? yes, the clew on this #3 just reaches the spreaders so it's very easy to judge Many paddle wheel knot meters read differently on opposite tacks. now this is something I'm going to have a closer look at as well. When I was working with high tech instrumentation on my old Cal-34 we ended up installing port and starboard paddle wheels with a switch box which I had to remember when tacking. It sounds like your boat is actually handling differently however, not just a speed difference. If all else fails try to get an experienced rigger and/or sailmaker to go out with you. thanks for the questions, it helps focus the mind. I've got some guys on the dock who've been there and back. If I can't get this sorted out in the next day or two, I'll ask for help. Cheers Bear in mind that too loose is more stressful and wearing on the rigging than too tight. "Just right", is obviously better than either too loose or too tight, but if you have to err on one side or the other... Many people alos make the mistake of releasing all tension on their adjustable backstay when leaving the boat. If you leave the forestay slack, it's constantly working all the turnbuckles and that is BAD. If your paddlewheel is off center as most are, you will get a different reading from port to starboard tack as the flow will be different. If you are trying to get the same reading on both tacks you may be "over trimming" thus making the boat "seem" to handle differently on one tack vs the other. I doubt it's the rigging. More likely the way the boat is loaded side to side. Move your crew around and see what happens. Regards JR |
rig tuning suggestions
mr.b wrote:
On Thu, 23 Jul 2009 22:26:23 -0400, Wayne.B wrote: On Thu, 23 Jul 2009 16:51:43 -0500, "mr.b" wrote: I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. If the rig tuning is off it should show up as a difference in sail shape. Does the main seem fuller or flatter from one tack to the other? no appreciable difference that I can see How about head stay sag? as I said, it sags probably 5 inches anyway off-centre. This can't be right. I guess my biggest concern is over-tightening the shrouds and stays. The seldén.com reference offered by another poster shows tightening turnbuckles a 3-4 mm. past hand tight will have your shrouds at 15% of their breaking strength which they recommend as correct. I think I've got 10mm past had tight already and the rig seems to me to be way loose, at least on the one tack. Another poster recommends a Loos gauge. Perhaps a useful tool. Are the jib leads in exactly the same position? leads are same size, same brand, same position on their tracks Have you tried adjusting them separately? Yes, but there is no apparent difference in jib shape or position -it's brand new i.e., 4 hrs of sail time. Is the jib "luff" - leech the same distance off the spreaders on both tacks? yes, the clew on this #3 just reaches the spreaders so it's very easy to judge Many paddle wheel knot meters read differently on opposite tacks. now this is something I'm going to have a closer look at as well. When I was working with high tech instrumentation on my old Cal-34 we ended up installing port and starboard paddle wheels with a switch box which I had to remember when tacking. It sounds like your boat is actually handling differently however, not just a speed difference. If all else fails try to get an experienced rigger and/or sailmaker to go out with you. thanks for the questions, it helps focus the mind. I've got some guys on the dock who've been there and back. If I can't get this sorted out in the next day or two, I'll ask for help. Cheers Sounds like your starboard shrouds are slipping at the terminals. Or the head stay. Are they? Brian |
rig tuning suggestions
Please make certain your speed measurements are accurate use your GPS. If
your rig appears symetrical under load on both tacks, it means that your hull isn't. The boat is plastic and they do change shape over time. This is not unusual. To test this, the boat needs to be out of the water. Build an absolutely square rectangle the length of the boat out of scrap and place the rectanglular frame in the center position around the hull, parallel with the center line of the hull. Take measurements equidistant along the longitudinal length of the hull at 90 degrees to the frame rails, both on the port and starboard sides. When you compare these measurements you will easily identify the problem. This is a day job on a boat this size and easy to accomplish. Of course you may not really want to know as ignorance is bliss, but if it will give you peace of mind, go for it. Of course you should also realize that it is not economic to correct. So you will either have to live with the asymetric shape or sell the boat and buy another. Steve "mr.b" wrote in message m... I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. |
rig tuning suggestions
Steve Lusardi wrote:
Please make certain your speed measurements are accurate use your GPS. If your rig appears symetrical under load on both tacks, it means that your hull isn't. The boat is plastic and they do change shape over time. This is not unusual. To test this, the boat needs to be out of the water. Build an absolutely square rectangle the length of the boat out of scrap and place the rectanglular frame in the center position around the hull, parallel with the center line of the hull. Take measurements equidistant along the longitudinal length of the hull at 90 degrees to the frame rails, both on the port and starboard sides. When you compare these measurements you will easily identify the problem. This is a day job on a boat this size and easy to accomplish. Of course you may not really want to know as ignorance is bliss, but if it will give you peace of mind, go for it. Of course you should also realize that it is not economic to correct. So you will either have to live with the asymetric shape or sell the boat and buy another. Steve "mr.b" wrote in message m... I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. I'm sticking to my guess that there is some current that's running against him on one tack. I know he disagrees, but that is my guess, especially if he's using a GPS to determine speed. One knot is a lot to have some condition like rig tuning, or hull distortion, that you can't see easily. |
rig tuning suggestions
mr.b wrote:
I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. It could be a tuning issue, though next time you haul the boat you might want to check to be sure the keel is properly aligned. --Alan |
rig tuning suggestions
"mr.b" wrote in message m... I'm consistently a kt. slower on the port tack than the starboard and it's starting to make me nuts. Almost as nuts as the "weather" on the Great Lakes this "summer". To start, all the standing rigging is new as of last year with about 40 hours of total sailing time on it. I measured the mast for plumbness using the main halyard, then tightened the uppers by hand keeping the mast in column. Then snugged the forestay hand tight. Then attempted to induce some prebend by tightening the aft stay, first hand tight, then with a wrench. Sighting up the main track shows a slight aft bend, maybe an inch over my 34' mast height, then checking again for straightness athwartship. Finally hand tightened the single inner shrouds. Out for sail testing and on the starboard tack the boat falls into the groove and runs right up to hull speed with a #3 and the full main in about 12-15kts of breeze. Slight weather helm and I can trim her for hands off at hull speed. Tack to port and we have to fall to leeward a bit to get her to accelerate and she never really gets into a comfortable groove. More pronounced weather helm and she seems to be struggling to come to hull speed. On both tacks the inner shrouds flop loosely and I know that will need to be dealt with next time out. As well, the forestay sags at least 5-6 inches from the centreline. I've read that "hand-tight" is good enough for shrouds and stays but this can't be right. My pointing ability can't be what it could be with such a loose rig. I'm looking for tuning hints here. It's just a conventional masthead rig with single lower shrouds and no backstay tensioner installed. Headsails are hank-on. Main has 3 full battens. Before you check for plumbness, start off by finding out if your chain plates are in the same plane. On a calm day, prop a 2x4 or something across the hull, position yourself right on the centerline and let the boat come to rest, then level the 2x4. Finally measure down to the chain plates. If you measure any difference, take that into account when you plumb the mast. Checking for plumbness using the main halyard in pretty inaccurate. Get a fifty-foot metal tape long enough to reach from the masthead to the chainplates and plumb it that way.Start the upper shrouds at a fairly tight hand tightness, check the plumbness, then adjust again by the same number of turns of the turnbuckle looser on one side and tighter on the other. Then snug up the lowers, maybe just a little bit looser than the uppers. Sight the mast up the sail track for straight. This is your starting point. Now go sailing in about ten or twelve knots of breeze, and flat water if you can find it. When you're close-hauled on starboard, sight up the sail track to see if the masthead is sagging off to leeward, or if there's a bow either way. If the masthead is sagging, luff up, tighten the upper a couple of turns, fall back off, check it again until the mast is standing straight when close-hauled. If it's bowing to leeward in the middle, tighten the lower on the weather side to bring it back into column. Go about, run through the same steps on the port tack. Then back to starboard, see if you've upset the tune on that tack, fix it, then back to port and touch it up. By now you're setting the rig up tight enough that you're feeling the burn in your hand when you make an adjustment, and you might even be needing a wrench on the turnbuckles if you're adjusting them under tension. By this time you're probably set up for transverse trim. Once you're back in the slip, do the metal tape test for plumbness again, and pull it back into plumb if necessary by loosening one side by a counted number of turns and tightening the other by the same number of turns. While you're doing all this close-hauled sailing, get right down on the deck and eyeball your weather chain plates and the deck as the boat works it way along. Put your hand on it. Any flexing or movement in the deck or the chainplate? See it on one side but not the other? If so, the load on the rig might be distorting the hull, causing the rig to flex more to one side than the other. In any case if you see something like that happening, stop worrying about the rig tuning for a while and fix the structural problem, then come back and try this again. For fore-and-aft trim, sounds to me like you just need to take it up a notch on tightness. In any case, a slack headstay would have the same effect on both tacks and wouldn't cause the assymetrical performance problem you're describing. You can go a lot tighter fore-and-aft than you're running it right now. Six inches of sag on a rig that size sounds like a lot to me with a #3 in that moderate breeze. If transverse rig trim was causing your problem, the chances are good that by the time you've gone through the process above the boat's sailing well on both tacks. If not, something else is going on. It may sound obvious, but check that the jib leads are set the same on both sides - same distance from the bow, same distance off the center-line. Check the mainsheet system to confirm that the boom is in the same orientation on both tacks - same mainsheet tension on both sides, not a little closer to the centerline on one tack than the other. Boom vang, if any, hauling the boom down harder on one tack than the other? Lots of boats have somewhat assymetrical trimming systems, because of mistakes in the way the gear leads. Someone else has already mentioned that sometimes boat hulls aren't symmetrical side-to-side. That's definitely true, and it could be that the boat's airfoil shape is just better on one side than the other. Sometimes it's the rudder that's shaped differently on one side than the other, giving you the impression of more weather helm on one tack. For the hull shape, it's kind of an involved process to discover if that's the problem, but it's a bit easier for a keel, and quite a bit easier for a rudder. Reshaping the rudder's not a big job, but refairing a keel is probably only worth it if you're a racer. Good luck, Tom Dacon |
rig tuning suggestions
Probably not a rig tuning issue but rather a hydrodynamic anomaly with
your paddlewheel. If the paddlewheel is mounted off of the boat's centerline it will rotate differently on on tack than the other and 1. differing depths (on one tack the paddlewheel is deeper than on the opposite tack. 2. the amount of leeways 'slip' the boat is experiencing versus #1 above. Unless the paddlewheel is accurately mounted ON the boats centerline it will virtually ALWAYS read differently when SAILING on different tacks. Its a problem of hydrodynamics versus different 'flow regimes'. |
rig tuning suggestions
On Sun, 26 Jul 2009 11:58:01 -0700, RichH wrote:
Probably not a rig tuning issue but rather a hydrodynamic anomaly with your paddlewheel. If the paddlewheel is mounted off of the boat's centerline it will rotate differently on on tack than the other and 1. differing depths (on one tack the paddlewheel is deeper than on the opposite tack. 2. the amount of leeways 'slip' the boat is experiencing versus #1 above. Unless the paddlewheel is accurately mounted ON the boats centerline it will virtually ALWAYS read differently when SAILING on different tacks. Its a problem of hydrodynamics versus different 'flow regimes'. Thanks Rich, I'm happy to have had so many quality responses to this thread. Lots of informed opinion and much to think about. In fact the paddlewheel is mounted off-centre to port by about 10 inches or so. I'll be back up to the old girl in a day or two and the bug- hunting is going to start with verifying your proposition. I know I do have some looseness in the rig that must be dealt with but nonetheless, your suggestion seems to satisfy Ockham's razor. We'll see. Cheers |
rig tuning suggestions
On Jul 26, 4:19*pm, "mr.b" wrote:
On Sun, 26 Jul 2009 11:58:01 -0700, RichH wrote: Probably not a rig tuning issue but rather a hydrodynamic anomaly with your paddlewheel. If the paddlewheel is mounted off of the boat's centerline it will rotate differently on on tack than the other and 1. differing depths (on one tack the paddlewheel is deeper than on the opposite tack. 2. the amount of leeways 'slip' the boat is experiencing versus #1 above. Unless the paddlewheel is accurately mounted ON the boats centerline it will virtually ALWAYS read differently when SAILING on different tacks. Its a problem of hydrodynamics versus different 'flow regimes'. Thanks Rich, I'm happy to have had so many quality responses to this thread. *Lots of informed opinion and much to think about. * In fact the paddlewheel is mounted off-centre to port by about 10 inches or so. *I'll be back up to the old girl in a day or two and the bug- hunting is going to start with verifying your proposition. *I know I do have some looseness in the rig that must be dealt with but nonetheless, your suggestion seems to satisfy Ockham's razor. We'll see. Cheers Easy to test out/verify .... MOTOR first on several tacks (on equivalent magnetic course that would equate to 'beating' with sails up but luffing and record speed versus; then, stop the engine and SAIL the tacks and record the speed / angle of heel, etc. The difference between the 4 sets of numbers will be your 'correction factor' for that speed versus apparent wind angle versus heel angle. You can build a full set of corrections for later usage if you want ... but best is to mount the paddlewheel ON the centerline to avoid hydrodynamic anomalies. BTW - 'most' instruments are NEVER direct read devices but usually need some 'correction factor' applied - pressure, temperature, speed, etc. etc. etc. etc. etc. its just the 'way of instrument usage in a technical world'. |
rig tuning suggestions
"RichH" wrote in message ... On Jul 26, 4:19 pm, "mr.b" wrote: On Sun, 26 Jul 2009 11:58:01 -0700, RichH wrote: Probably not a rig tuning issue but rather a hydrodynamic anomaly with your paddlewheel. If the paddlewheel is mounted off of the boat's centerline it will rotate differently on on tack than the other and 1. differing depths (on one tack the paddlewheel is deeper than on the opposite tack. 2. the amount of leeways 'slip' the boat is experiencing versus #1 above. Unless the paddlewheel is accurately mounted ON the boats centerline it will virtually ALWAYS read differently when SAILING on different tacks. Its a problem of hydrodynamics versus different 'flow regimes'. Thanks Rich, I'm happy to have had so many quality responses to this thread. Lots of informed opinion and much to think about. In fact the paddlewheel is mounted off-centre to port by about 10 inches or so. I'll be back up to the old girl in a day or two and the bug- hunting is going to start with verifying your proposition. I know I do have some looseness in the rig that must be dealt with but nonetheless, your suggestion seems to satisfy Ockham's razor. We'll see. Cheers Easy to test out/verify .... MOTOR first on several tacks (on equivalent magnetic course that would equate to 'beating' with sails up but luffing and record speed versus; then, stop the engine and SAIL the tacks and record the speed / angle of heel, etc. The difference between the 4 sets of numbers will be your 'correction factor' for that speed versus apparent wind angle versus heel angle. You can build a full set of corrections for later usage if you want ... but best is to mount the paddlewheel ON the centerline to avoid hydrodynamic anomalies. BTW - 'most' instruments are NEVER direct read devices but usually need some 'correction factor' applied - pressure, temperature, speed, etc. etc. etc. etc. etc. its just the 'way of instrument usage in a technical world'. I know of no production boats with the paddle wheel on the centerline. Regards, JR |
rig tuning suggestions
On Tue, 28 Jul 2009 08:48:46 -0400, "JR" wrote:
I know of no production boats with the paddle wheel on the centerline. Regards, JR It is usually impractical unless you are willing to live with a transducer in the middle of your forward cabin sole. In addition to being exactly on the centerline and precisely aligned, it is also necessary to be at least a foot or two forward of the keel. We decided that port and starboard transducers were the best of the bad choices available. That has its own issues however, not the least of which is switching on every tack or jibe. It would also be highly desirable to have separate calibration controls for each transducer but that is even more difficult in most cases. |
rig tuning suggestions
"JR" wrote in message
... I know of no production boats with the paddle wheel on the centerline. Regards, JR I have one... Mounted on the keel line near the bow, along with a depth and temp sounder it does very nicely. Transducer and senders connect to the fish finder which, unlike my other two depth gauges, allow positive as well as negative offset, so that's the "true" depth meter, where the others are "under-keel" meters... Go to the bow, drill the appropriate hole, apply the appropriate fairing, and now you have a centerline mounted instrument :{)) L8R Skip, still working on the boat but having the end in sight. Painting the last parts starts tomorrow... -- Morgan 461 #2 SV Flying Pig KI4MPC See our galleries at www.justpickone.org/skip/gallery ! Follow us at http://groups.yahoo.com/group/TheFlyingPigLog and/or http://groups.google.com/group/flyingpiglog "You are never given a wish without also being given the power to make it come true. You may have to work for it however." (and) "There is no such thing as a problem without a gift for you in its hand (Richard Bach) |
rig tuning suggestions
Putting the paddlewheel on the centerline will also generate some
potential problems ..... it has to be mounted so that it cant be destroyed by the sling of a travellift when the boat is hauled ... not an easy thing to do. |
rig tuning suggestions
On Tue, 28 Jul 2009 10:34:52 -0700 (PDT), RichH
wrote: Putting the paddlewheel on the centerline will also generate some potential problems ..... it has to be mounted so that it cant be destroyed by the sling of a travellift when the boat is hauled ... not an easy thing to do. The easiest way to manage that is to pull the paddle wheel and insert the dummy plug before haul out. If you are really religious about your instrument calibration it is best to pull the paddle wheels every time you come back in from sailing. It helps to prevent growth or slime from forming and throwing off the speed readings. When you are trying to accurately compute true wind direction and speed it doesn't take much knot meter error to throw the whole calculation out of kilter. |
rig tuning suggestions
"RichH" wrote in message ... Putting the paddlewheel on the centerline will also generate some potential problems ..... it has to be mounted so that it cant be destroyed by the sling of a travellift when the boat is hauled ... not an easy thing to do. I was thinking more along the line of hull strength. Regards, JR |
rig tuning suggestions
On Tue, 28 Jul 2009 12:17:46 -0400, "Flying Pig"
wrote: I know of no production boats with the paddle wheel on the centerline. Regards, JR I have one... Mounted on the keel line near the bow, along with a depth and temp sounder it does very nicely. Do you generally get equal knot meter readings on opposite tacks, everything else being more or less equal? |
rig tuning suggestions
Wayne.B wrote:
On Tue, 28 Jul 2009 10:34:52 -0700 (PDT), RichH wrote: Putting the paddlewheel on the centerline will also generate some potential problems ..... it has to be mounted so that it cant be destroyed by the sling of a travellift when the boat is hauled ... not an easy thing to do. The easiest way to manage that is to pull the paddle wheel and insert the dummy plug before haul out. If you are really religious about your instrument calibration it is best to pull the paddle wheels every time you come back in from sailing. It helps to prevent growth or slime from forming and throwing off the speed readings. When you are trying to accurately compute true wind direction and speed it doesn't take much knot meter error to throw the whole calculation out of kilter. I want to pull my paddle wheel out and clean it, but I've never done it before. OR even seen it done.... Seems like it's not that far below the water line that water would come gushing in real big. But it's still a hole below the water line! |
rig tuning suggestions
"cavelamb" wrote in message
... Wayne.B wrote: On Tue, 28 Jul 2009 10:34:52 -0700 (PDT), RichH wrote: Putting the paddlewheel on the centerline will also generate some potential problems ..... it has to be mounted so that it cant be destroyed by the sling of a travellift when the boat is hauled ... not an easy thing to do. The easiest way to manage that is to pull the paddle wheel and insert the dummy plug before haul out. If you are really religious about your instrument calibration it is best to pull the paddle wheels every time you come back in from sailing. It helps to prevent growth or slime from forming and throwing off the speed readings. When you are trying to accurately compute true wind direction and speed it doesn't take much knot meter error to throw the whole calculation out of kilter. I want to pull my paddle wheel out and clean it, but I've never done it before. OR even seen it done.... Seems like it's not that far below the water line that water would come gushing in real big. But it's still a hole below the water line! It's not a big deal really... Just have the plastic plug ready to go. You'll get maybe a quart of water. -- "j" ganz @@ www.sailnow.com |
rig tuning suggestions
On Tue, 28 Jul 2009 17:49:09 -0500, cavelamb
wrote: Wayne.B wrote: On Tue, 28 Jul 2009 10:34:52 -0700 (PDT), RichH wrote: Putting the paddlewheel on the centerline will also generate some potential problems ..... it has to be mounted so that it cant be destroyed by the sling of a travellift when the boat is hauled ... not an easy thing to do. The easiest way to manage that is to pull the paddle wheel and insert the dummy plug before haul out. If you are really religious about your instrument calibration it is best to pull the paddle wheels every time you come back in from sailing. It helps to prevent growth or slime from forming and throwing off the speed readings. When you are trying to accurately compute true wind direction and speed it doesn't take much knot meter error to throw the whole calculation out of kilter. I want to pull my paddle wheel out and clean it, but I've never done it before. OR even seen it done.... Seems like it's not that far below the water line that water would come gushing in real big. But it's still a hole below the water line! Mentally rehearse the steps and have the dummy plug ready to put in with one hand as you pull out the live one with the other. Even if you are very clumsy, you won't get more than a quart or two of water. I do it all the time, and I get about a cup full at most. The water comes in about like what comes out of a garden hose. Maybe a bit less pressure. |
rig tuning suggestions
On Tue, 28 Jul 2009 17:49:09 -0500, cavelamb
wrote: I want to pull my paddle wheel out and clean it, but I've never done it before. OR even seen it done.... Seems like it's not that far below the water line that water would come gushing in real big. But it's still a hole below the water line! Assuming that you have a dummy plug it is really quite easy, have it close at hand. I used to atttach a string to mine and leave it tied to the paddle wheel housing so that I always knew where it was. Pull the paddle wheel plug and immediately put your free hand over the hole to minimize the inrush. Grab the dummy plug with your other hand and immediately insert. Twist down the collar on the dummy plug to lock it in place and you are ready to start cleaning the paddle wheel. After you've done it a couple of times it becomes routine, just make sure you have the dummy ready to go. |
rig tuning suggestions
"Wayne.B" wrote in message ... On Tue, 28 Jul 2009 12:17:46 -0400, "Flying Pig" wrote: I know of no production boats with the paddle wheel on the centerline. Regards, JR I have one... Mounted on the keel line near the bow, along with a depth and temp sounder it does very nicely. Do you generally get equal knot meter readings on opposite tacks, everything else being more or less equal? I sail a Matilda 20. Nearly 8ft beam. She gets fat quick and tapers off quickly in the last 3rd. The aft hull section is more of a V than a rounded shape. Her main has a ton of roach so that in a good breeze or surfing she will plane nicely. The paddle wheel is about a foot starboard of centerline and I do see a slight diff but I don't worry about it. I trim for max speed on each tack if that is what I'm looking for that day. Regards, JR |
rig tuning suggestions
On Wed, 29 Jul 2009 00:43:29 -0400, "JR" wrote:
The paddle wheel is about a foot starboard of centerline and I do see a slight diff but I don't worry about it. I trim for max speed on each tack if that is what I'm looking for that day. That's fine as long as you aren't doing vector calculations with the speed to compute true wind numbers or VPP/polar predictions. |
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