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Re: [SabreSailboat] sabre 34 mk1 mast wobble

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  • Dan Trainor
    Hello Richard, I am thinking (a guess without actually being on your deck) that the rig may be over tight. Especially the Upper Cap shrouds. When over tight,
    Message 1 of 10 , Aug 28, 2013
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      Hello Richard,

      I am thinking (a guess without actually being on your deck) that the rig may be over tight.  Especially the Upper Cap shrouds.  When over tight, it tends to set up what Brian Toss calls a "spaghetti" tune.  Imagine a strand of uncooked spaghetti with your finger pushing down on it, it makes for an unstable situation due to over compression (to some degree).   Soooo, what I would do is loosen all wires and build up the tension gradually.  First with lowers to establish a base foundation, then tighten uppers again (without over tightening).  Try to make it as loose as you can within reason. Keeping Mast straight vertical by using the halyard as a measuring stick.  And also of course sighting up the mast track to determine if upper mast is bending at top.  If mast is straight in those two respects and wires are loose and not over tight, then your good.  But the trick to address this kind of mast pumping is to loosen wire tension (not tighten) such that the mast can breath rather than being over compressed and unstable like.  Again, not being there and not knowing what your wire tensions are, I can only speculate.  For a reference with Loos Gauge, my tensions are below.  But your mileage may very.  Also, be sure to tighten forward lowers first (tighter than aft lowers) as you build the lower foundation such that when you later tighten your backstay, you can form a nice pre-bend.  The pre-bend (if caps are not too tight) also can significantly improve your pumping issue.  Hope that made sense.  Easier to show you, than to describe it.  Hope this gives you some thoughts to work with.  

      dan Sabre32


                        Wire     PT-2    Model B

      Cap Shrouds    9/32 – 42-42

      Forward Lowers 1/4  - 36-36

      Aft Lowers     1/4  - 33-33

      Back Stay      9/32 -  40   



      On Wed, Aug 28, 2013 at 5:35 PM, rssimons@... <rssimons@...> wrote:
       

      Hi I have a mk1 with a single spreader and when motoring into a chop the mast seems to move back and forth at the spreaders,its a bit disconcerting. I tried tightening the lower stays but does not seem much better. thanks for you help Richard




      --
      Dan
    • John Kalinowski
      +1. Get or borrow a Loos gauge And read sail and rig tuning by ivar dedekam Sent from my iPhone ... +1. Get or borrow a Loos gauge And read sail and rig tuning
      Message 2 of 10 , Aug 29, 2013
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        +1. 
        Get or borrow a Loos gauge

        And read sail and rig tuning by ivar dedekam

        Sent from my iPhone

        On Aug 28, 2013, at 7:37 PM, Dan Trainor <dptrainor@...> wrote:

         

        Hello Richard,

        I am thinking (a guess without actually being on your deck) that the rig may be over tight.  Especially the Upper Cap shrouds.  When over tight, it tends to set up what Brian Toss calls a "spaghetti" tune.  Imagine a strand of uncooked spaghetti with your finger pushing down on it, it makes for an unstable situation due to over compression (to some degree).   Soooo, what I would do is loosen all wires and build up the tension gradually.  First with lowers to establish a base foundation, then tighten uppers again (without over tightening).  Try to make it as loose as you can within reason. Keeping Mast straight vertical by using the halyard as a measuring stick.  And also of course sighting up the mast track to determine if upper mast is bending at top.  If mast is straight in those two respects and wires are loose and not over tight, then your good.  But the trick to address this kind of mast pumping is to loosen wire tension (not tighten) such that the mast can breath rather than being over compressed and unstable like.  Again, not being there and not knowing what your wire tensions are, I can only speculate.  For a reference with Loos Gauge, my tensions are below.  But your mileage may very.  Also, be sure to tighten forward lowers first (tighter than aft lowers) as you build the lower foundation such that when you later tighten your backstay, you can form a nice pre-bend.  The pre-bend (if caps are not too tight) also can significantly improve your pumping issue.  Hope that made sense.  Easier to show you, than to describe it.  Hope this gives you some thoughts to work with.  

        dan Sabre32


                          Wire     PT-2    Model B

        Cap Shrouds    9/32 – 42-42

        Forward Lowers 1/4  - 36-36

        Aft Lowers     1/4  - 33-33

        Back Stay      9/32 -  40   



        On Wed, Aug 28, 2013 at 5:35 PM, rssimons@... <rssimons@...> wrote:
         

        Hi I have a mk1 with a single spreader and when motoring into a chop the mast seems to move back and forth at the spreaders,its a bit disconcerting. I tried tightening the lower stays but does not seem much better. thanks for you help Richard




        --
        Dan

      • rssimons@snet.net
        Thanks, thats really helpfull, i will find a gauge and do some checking...
        Message 3 of 10 , Aug 29, 2013
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          Thanks, thats really helpfull, i will find a gauge and do some checking...

          --- In Sabresailboat@yahoogroups.com, "rssimons@..." <rssimons@...> wrote:
          >
          > Hi I have a mk1 with a single spreader and when motoring into a chop the mast seems to move back and forth at the spreaders,its a bit disconcerting. I tried tightening the lower stays but does not seem much better. thanks for you help Richard
          >
        • sailor11767
          Upper shroud tension is pretty easy, especially on a cruising boat. Simply tighten until when heeled well (20-25 degrees) your leeward uppers are somewhat
          Message 4 of 10 , Aug 31, 2013
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            Upper shroud tension is pretty easy, especially on a cruising boat. Simply tighten until when heeled well (20-25 degrees) your leeward uppers are somewhat loose (not floppy, but essentially no tension). Any more than that doesn't help any.

            Lowers are a whole 'nother problem. And backstay/forestay is voodoo magic.

            Harry
            Analysis
            '79 S34-I #063
            Mill Creek, Annapolis

            --- In Sabresailboat@yahoogroups.com, Dan Trainor <dptrainor@...> wrote:
            >
            > Hello Richard,
            >
            > I am thinking (a guess without actually being on your deck) that the rig
            > may be over tight. Especially the Upper Cap shrouds. When over tight, it
            > tends to set up what Brian Toss calls a "spaghetti" tune. Imagine a strand
            > of uncooked spaghetti with your finger pushing down on it, it makes for an
            > unstable situation due to over compression (to some degree). Soooo, what
            > I would do is loosen all wires and build up the tension gradually. First
            > with lowers to establish a base foundation, then tighten uppers again
            > (without over tightening). Try to make it as loose as you can within
            > reason. Keeping Mast straight vertical by using the halyard as a measuring
            > stick. And also of course sighting up the mast track to determine if upper
            > mast is bending at top. If mast is straight in those two respects and
            > wires are loose and not over tight, then your good. But the trick to
            > address this kind of mast pumping is to loosen wire tension (not tighten)
            > such that the mast can breath rather than being over compressed and
            > unstable like. Again, not being there and not knowing what your wire
            > tensions are, I can only speculate. For a reference with Loos Gauge, my
            > tensions are below. But your mileage may very. Also, be sure to tighten
            > forward lowers first (tighter than aft lowers) as you build the lower
            > foundation such that when you later tighten your backstay, you can form a
            > nice pre-bend. The pre-bend (if caps are not too tight) also can
            > significantly improve your pumping issue. Hope that made sense. Easier to
            > show you, than to describe it. Hope this gives you some thoughts to work
            > with.
            >
            > dan Sabre32
            >
            >
            > * Wire PT-2 Model B*
            >
            > *Cap Shrouds 9/32 – 42-42*
            >
            > *Forward Lowers 1/4 - 36-36*
            >
            > *Aft Lowers 1/4 - 33-33*
            >
            > *Back Stay 9/32 - 40 *
            >
            >
            > On Wed, Aug 28, 2013 at 5:35 PM, rssimons@... <rssimons@...>wrote:
            >
            > > **
            > >
            > >
            > > Hi I have a mk1 with a single spreader and when motoring into a chop the
            > > mast seems to move back and forth at the spreaders,its a bit disconcerting.
            > > I tried tightening the lower stays but does not seem much better. thanks
            > > for you help Richard
            > >
            > >
            > >
            >
            >
            >
            > --
            > Dan
            >
          • Daniel Trainor
            Yes. The dynamic tuning under sail. Sent from my iPhone ... Yes. The dynamic tuning under sail. Sent from my iPhone On Aug 31, 2013, at 8:40 PM, sailor11767
            Message 5 of 10 , Sep 1, 2013
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              Yes. The dynamic tuning under sail.

              Sent from my iPhone

              On Aug 31, 2013, at 8:40 PM, "sailor11767" <sailor11767@...> wrote:

               

              Upper shroud tension is pretty easy, especially on a cruising boat. Simply tighten until when heeled well (20-25 degrees) your leeward uppers are somewhat loose (not floppy, but essentially no tension). Any more than that doesn't help any.

              Lowers are a whole 'nother problem. And backstay/forestay is voodoo magic.

              Harry
              Analysis
              '79 S34-I #063
              Mill Creek, Annapolis

              --- In Sabresailboat@yahoogroups.com, Dan Trainor <dptrainor@...> wrote:
              >
              > Hello Richard,
              >
              > I am thinking (a guess without actually being on your deck) that the rig
              > may be over tight. Especially the Upper Cap shrouds. When over tight, it
              > tends to set up what Brian Toss calls a "spaghetti" tune. Imagine a strand
              > of uncooked spaghetti with your finger pushing down on it, it makes for an
              > unstable situation due to over compression (to some degree). Soooo, what
              > I would do is loosen all wires and build up the tension gradually. First
              > with lowers to establish a base foundation, then tighten uppers again
              > (without over tightening). Try to make it as loose as you can within
              > reason. Keeping Mast straight vertical by using the halyard as a measuring
              > stick. And also of course sighting up the mast track to determine if upper
              > mast is bending at top. If mast is straight in those two respects and
              > wires are loose and not over tight, then your good. But the trick to
              > address this kind of mast pumping is to loosen wire tension (not tighten)
              > such that the mast can breath rather than being over compressed and
              > unstable like. Again, not being there and not knowing what your wire
              > tensions are, I can only speculate. For a reference with Loos Gauge, my
              > tensions are below. But your mileage may very. Also, be sure to tighten
              > forward lowers first (tighter than aft lowers) as you build the lower
              > foundation such that when you later tighten your backstay, you can form a
              > nice pre-bend. The pre-bend (if caps are not too tight) also can
              > significantly improve your pumping issue. Hope that made sense. Easier to
              > show you, than to describe it. Hope this gives you some thoughts to work
              > with.
              >
              > dan Sabre32
              >
              >
              > * Wire PT-2 Model B*
              >
              > *Cap Shrouds 9/32 – 42-42*
              >
              > *Forward Lowers 1/4 - 36-36*
              >
              > *Aft Lowers 1/4 - 33-33*
              >
              > *Back Stay 9/32 - 40 *
              >
              >
              > On Wed, Aug 28, 2013 at 5:35 PM, rssimons@... <rssimons@...>wrote:
              >
              > > **
              > >
              > >
              > > Hi I have a mk1 with a single spreader and when motoring into a chop the
              > > mast seems to move back and forth at the spreaders,its a bit disconcerting.
              > > I tried tightening the lower stays but does not seem much better. thanks
              > > for you help Richard
              > >
              > >
              > >
              >
              >
              >
              > --
              > Dan
              >

            • rssimons@snet.net
              ... I checked the tension in the uppers and they were about 45 so I tried loosening them, but that made them too slack when heeling, so i reset them probably a
              Message 6 of 10 , Sep 2, 2013
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                >
                I checked the tension in the uppers and they were about 45 so I tried loosening them, but that made them too slack when heeling, so i reset them probably a bit tighter than before and will try that. thanks for the ideas. Richard
              • smofishlaw
                The 34MK2 manual, Section 13, has instructions for adjusting that rig-albeit a double spreader rig-which has some suggestions about balancing the lowers
                Message 7 of 10 , Sep 3, 2013
                • 0 Attachment

                  The 34MK2 manual, Section 13, has instructions for adjusting that rig-albeit a double spreader rig-which has some suggestions about balancing the lowers shrouds to prevent pounding in a seaway.  I emailed it to you as well. I think the basic principles are applicable to your rig.



                  --- In Sabresailboat@yahoogroups.com, <sabresailboat@yahoogroups.com> wrote:

                  >
                  I checked the tension in the uppers and they were about 45 so I tried loosening them, but that made them too slack when heeling, so i reset them probably a bit tighter than before and will try that. thanks for the ideas. Richard
                • William Kellett
                  Last spring (2013?) there was an exchange of ideas here on rig tensions for tuning a Sabre 20 MK III. The suggested tensions were provided. Unfortunately I
                  Message 8 of 10 , Feb 25, 2014
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                    Last spring (2013?) there was an exchange of ideas here on rig tensions for tuning a Sabre 20 MK III.  The suggested tensions were provided.  Unfortunately I lost my copy and now cannot find the reference with a search.  Do you have any suggestions about who and when that info was shown here?  If yes I would appreciate the reference.

                     

                    Bill

                    S28 MK III #585

                     

                    From: Sabresailboat@yahoogroups.com [mailto:Sabresailboat@yahoogroups.com] On Behalf Of John Kalinowski
                    Sent: Thursday, August 29, 2013 10:13 AM
                    To: Sabresailboat@yahoogroups.com
                    Subject: Re: [SabreSailboat] sabre 34 mk1 mast wobble

                     

                     

                    +1. 

                    Get or borrow a Loos gauge

                     

                    And read sail and rig tuning by ivar dedekam

                    Sent from my iPhone


                    On Aug 28, 2013, at 7:37 PM, Dan Trainor <dptrainor@...> wrote:

                     

                    Hello Richard,

                     

                    I am thinking (a guess without actually being on your deck) that the rig may be over tight.  Especially the Upper Cap shrouds.  When over tight, it tends to set up what Brian Toss calls a "spaghetti" tune.  Imagine a strand of uncooked spaghetti with your finger pushing down on it, it makes for an unstable situation due to over compression (to some degree).   Soooo, what I would do is loosen all wires and build up the tension gradually.  First with lowers to establish a base foundation, then tighten uppers again (without over tightening).  Try to make it as loose as you can within reason. Keeping Mast straight vertical by using the halyard as a measuring stick.  And also of course sighting up the mast track to determine if upper mast is bending at top.  If mast is straight in those two respects and wires are loose and not over tight, then your good.  But the trick to address this kind of mast pumping is to loosen wire tension (not tighten) such that the mast can breath rather than being over compressed and unstable like.  Again, not being there and not knowing what your wire tensions are, I can only speculate.  For a reference with Loos Gauge, my tensions are below.  But your mileage may very.  Also, be sure to tighten forward lowers first (tighter than aft lowers) as you build the lower foundation such that when you later tighten your backstay, you can form a nice pre-bend.  The pre-bend (if caps are not too tight) also can significantly improve your pumping issue.  Hope that made sense.  Easier to show you, than to describe it.  Hope this gives you some thoughts to work with.  

                     

                    dan Sabre32

                     

                     

                                      Wire     PT-2    Model B

                    Cap Shrouds    9/32 – 42-42

                    Forward Lowers 1/4  - 36-36

                    Aft Lowers     1/4  - 33-33

                    Back Stay      9/32 -  40   

                     

                    On Wed, Aug 28, 2013 at 5:35 PM, rssimons@... <rssimons@...> wrote:

                     

                    Hi I have a mk1 with a single spreader and when motoring into a chop the mast seems to move back and forth at the spreaders,its a bit disconcerting. I tried tightening the lower stays but does not seem much better. thanks for you help Richard



                     

                    --
                    Dan

                  • Richard Coerse
                    Bill, I am confused! You have a subject line in your post of /*sabre 34 mk1*/ mast wobble and you are asking about rig tensions on a */Sabre 20/* /*MK
                    Message 9 of 10 , Feb 25, 2014
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                      Bill,
                      I am confused!  You have a subject line in your post of "sabre 34 mk1 mast wobble" and you are asking about rig tensions on a
                      "Sabre 20 MK III".  No such boat was ever built by Sabre to my knowledge and you signed off as a S28 MKIII owner.  Which boat are you wanting tuning information for?
                      Dick Coerse
                      "Early Light"
                      S-34 MK I



                      William Kellett wrote:
                       

                      Last spring (2013?) there was an exchange of ideas here on rig tensions for tuning a .  The suggested tensions were provided.  Unfortunately I lost my copy and now cannot find the reference with a search.  Do you have any suggestions about who and when that info was shown here?  If yes I would appreciate the reference.

                       

                      Bill

                      S28 MK III #585

                       

                      From: Sabresailboat@yahoogroups.com [mailto:Sabresailboat@yahoogroups.com] On Behalf Of John Kalinowski
                      Sent: Thursday, August 29, 2013 10:13 AM
                      To: Sabresailboat@yahoogroups.com
                      Subject: Re: [SabreSailboat] sabre 34 mk1 mast wobble

                       

                       

                      +1. 

                      Get or borrow a Loos gauge

                       

                      And read sail and rig tuning by ivar dedekam

                      Sent from my iPhone


                      On Aug 28, 2013, at 7:37 PM, Dan Trainor <dptrainor@...> wrote:

                       

                      Hello Richard,

                       

                      I am thinking (a guess without actually being on your deck) that the rig may be over tight.  Especially the Upper Cap shrouds.  When over tight, it tends to set up what Brian Toss calls a "spaghetti" tune.  Imagine a strand of uncooked spaghetti with your finger pushing down on it, it makes for an unstable situation due to over compression (to some degree).   Soooo, what I would do is loosen all wires and build up the tension gradually.  First with lowers to establish a base foundation, then tighten uppers again (without over tightening).  Try to make it as loose as you can within reason. Keeping Mast straight vertical by using the halyard as a measuring stick.  And also of course sighting up the mast track to determine if upper mast is bending at top.  If mast is straight in those two respects and wires are loose and not over tight, then your good.  But the trick to address this kind of mast pumping is to loosen wire tension (not tighten) such that the mast can breath rather than being over compressed and unstable like.  Again, not being there and not knowing what your wire tensions are, I can only speculate.  For a reference with Loos Gauge, my tensions are below.  But your mileage may very.  Also, be sure to tighten forward lowers first (tighter than aft lowers) as you build the lower foundation such that when you later tighten your backstay, you can form a nice pre-bend.  The pre-bend (if caps are not too tight) also can significantly improve your pumping issue.  Hope that made sense.  Easier to show you, than to describe it.  Hope this gives you some thoughts to work with.  

                       

                      dan Sabre32

                       

                       

                                        Wire     PT-2    Model B

                      Cap Shrouds    9/32 – 42-42

                      Forward Lowers 1/4  - 36-36

                      Aft Lowers     1/4  - 33-33

                      Back Stay      9/32 -  40   

                       

                      On Wed, Aug 28, 2013 at 5:35 PM, rssimons@... <rssimons@...> wrote:

                       

                      Hi I have a mk1 with a single spreader and when motoring into a chop the mast seems to move back and forth at the spreaders,its a bit disconcerting. I tried tightening the lower stays but does not seem much better. thanks for you help Richard



                       

                      --
                      Dan


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