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Pre Bend

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  • Stephen M. Hollingsworth
    First, Art great job on the Mainsheet article on Pre-Bend, it could not have come at a better time for me. Myself and the other C26 owner s at the marina have
    Message 1 of 4 , Nov 25, 2012

    First, Art great job on the Mainsheet article on Pre-Bend, it could not have come at a better time for me.  Myself and the other C26 owner’s at the marina have been wrestling with this issue for years with limited success, so I was glad to see the article.

     

     

    Now, I realize that we have discussed the Pre-Bend issue before and Catalina’s recommended solution that involves using a shim plate but I had an incident last winter with my mast that got me rethinking the whole issue. Long story short, last spring, I had my mast off the boat and sitting on horses when some highs winds caused my mast to fall and land on its spreaders. There was no physical damage to the mast but after examining the spreaders, I noticed that they had some horizontal play (3” from front to back) but I just contributed the extra play from the years of the pin hole being slighting wallowing out from age. With that all said, the question I have is on Catalina’s intent or purpose for the swept back spreaders on the C26’s. I know of all the typical reasons why designers use this design, mostly around the fractional rigs but it got me thinking about Catalina using the swept back spreaders (w/ the upper stays) to help introduce per-bend on this boat. With my spreaders having “play”, I’m starting to think that if the (my) Spreaders are not rigid to the mast, it would not matter how much stay tension I would apply, the spreaders would not be able to do their job and introduce any bend. Am I correct in thinking this? I have also noticed that with the other three C26’s at the marina, every Capri has different configuration for attaching the spreaders to the mast. On my capri (see attachments), I basically have a tee-bar riveted to the mast and the spreader slides over the bar with a pin to attach the arm to the bar.  I wish I had the mount of another C26 owner at the lake in which his spreaders fit into a “sleeve” mount which in returns, does not allow the end of the spreader to have any horizontal movement. I would love to hear the groups opinion on this topic and the effect of the spreaders on pre-bend and if the spreaders should have any horizontal play.

     

     

     

     

     

    Cheers

    Stephen

     

  • Stephen
    Happy Holiday s Everyone. I just wanted to follow up with everyone and share a discussion that I had with a Brion Toss, a very well respected rigger. The link
    Message 2 of 4 , Dec 27, 2012
      Happy Holiday's Everyone.

      I just wanted to follow up with everyone and share a discussion that I had with a Brion Toss, a very well respected rigger. The link to the forum discussion is below.

      http://www.briontoss.com/spartalk/showthread.php?t=2340


      Cheers
      Stephen



      --- In capri26@yahoogroups.com, "Stephen M. Hollingsworth" <smh@...> wrote:
      >
      > First, Art great job on the Mainsheet article on Pre-Bend, it could not have
      > come at a better time for me. Myself and the other C26 owner's at the
      > marina have been wrestling with this issue for years with limited success,
      > so I was glad to see the article.
      >
      >
      >
      >
      >
      > Now, I realize that we have discussed the Pre-Bend issue before and
      > Catalina's recommended solution that involves using a shim plate but I had
      > an incident last winter with my mast that got me rethinking the whole issue.
      > Long story short, last spring, I had my mast off the boat and sitting on
      > horses when some highs winds caused my mast to fall and land on its
      > spreaders. There was no physical damage to the mast but after examining the
      > spreaders, I noticed that they had some horizontal play (3" from front to
      > back) but I just contributed the extra play from the years of the pin hole
      > being slighting wallowing out from age. With that all said, the question I
      > have is on Catalina's intent or purpose for the swept back spreaders on the
      > C26's. I know of all the typical reasons why designers use this design,
      > mostly around the fractional rigs but it got me thinking about Catalina
      > using the swept back spreaders (w/ the upper stays) to help introduce
      > per-bend on this boat. With my spreaders having "play", I'm starting to
      > think that if the (my) Spreaders are not rigid to the mast, it would not
      > matter how much stay tension I would apply, the spreaders would not be able
      > to do their job and introduce any bend. Am I correct in thinking this? I
      > have also noticed that with the other three C26's at the marina, every Capri
      > has different configuration for attaching the spreaders to the mast. On my
      > capri (see attachments), I basically have a tee-bar riveted to the mast and
      > the spreader slides over the bar with a pin to attach the arm to the bar. I
      > wish I had the mount of another C26 owner at the lake in which his spreaders
      > fit into a "sleeve" mount which in returns, does not allow the end of the
      > spreader to have any horizontal movement. I would love to hear the groups
      > opinion on this topic and the effect of the spreaders on pre-bend and if the
      > spreaders should have any horizontal play.
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      >
      > Cheers
      >
      > Stephen
      >
    • Leighton Westlake
      The mast is designed for a 3-inch pre-bend. Otherwise the mainsail will not fit correctly and it will bag in the center. If you order a new main (As I did
      Message 3 of 4 , Dec 27, 2012

        The mast is designed for a 3-inch pre-bend.  Otherwise the mainsail will not fit correctly and it will bag in the center.  If you order a new main (As I did from North) it will come cut for a pre-bend as that is the specification from Catalina.

         

        The spreaders should be tight to the mast and the stays tensioned properly.  Obviously the spreaders and the stays  were not tensioned correctly and it allowed for play in the mast that led to the spreader damage. 

         

        Mine has a new rig professionally installed and the pre-bend (Goes faster by ½ knot at least and no back-winding of the main.) is there allowing the proper tensioning of the stays.  Of note we did eliminate the offset backstay for a split design that allowed for equal tensioning of the upper and lower stays and also has provision for a backstay tensioner - if I ever really wanted one.

         

        If you have any questions, please feel free to contact me.

        Signature-LDW

        Leighton Danis Westlake, Jr., PE, PLS

        Principal Engineer

        a division of DANIS LOGO

        10175 Flag Dr, Palm Beach Gardens, FL 33410-4775           

        Tel:  561-799-5280                                                                                                      

        Fax: 561-799-5776                                                                                                       )

        Cell: 561-222-0714

        email: leighton@...

         

        Privilaged Correspondence

         

        This e-mail and any attachments are intended only for the named recipient(s) and may contain information that is legally privileged, confidential, or exempt from disclosure under applicable law. If you have received this message in error, or are not the named recipient(s), you may not retain copy or use this e-mail or any attachment for any purpose or disclose all or any part of the contents to any other person. Any such dissemination, distribution or copying of this e-mail or its attachments is strictly prohibited. Please immediately notify the sender and permanently delete this e-mail and any attachment from your computer.

         

         

        From: capri26@yahoogroups.com [mailto:capri26@yahoogroups.com] On Behalf Of Stephen
        Sent: Thursday, December 27, 2012 4:38 PM
        To: capri26@yahoogroups.com
        Subject: [capri26] Re: Pre Bend

         

         



        Happy Holiday's Everyone.

        I just wanted to follow up with everyone and share a discussion that I had with a Brion Toss, a very well respected rigger. The link to the forum discussion is below.

        http://www.briontoss.com/spartalk/showthread.php?t=2340

        Cheers
        Stephen

        --- In capri26@yahoogroups.com, "Stephen M. Hollingsworth" <smh@...> wrote:
        >
        > First, Art great job on the Mainsheet article on Pre-Bend, it could not have
        > come at a better time for me. Myself and the other C26 owner's at the
        > marina have been wrestling with this issue for years with limited success,
        > so I was glad to see the article.
        >
        >
        >
        >
        >
        > Now, I realize that we have discussed the Pre-Bend issue before and
        > Catalina's recommended solution that involves using a shim plate but I had
        > an incident last winter with my mast that got me rethinking the whole issue.
        > Long story short, last spring, I had my mast off the boat and sitting on
        > horses when some highs winds caused my mast to fall and land on its
        > spreaders. There was no physical damage to the mast but after examining the
        > spreaders, I noticed that they had some horizontal play (3" from front to
        > back) but I just contributed the extra play from the years of the pin hole
        > being slighting wallowing out from age. With that all said, the question I
        > have is on Catalina's intent or purpose for the swept back spreaders on the
        > C26's. I know of all the typical reasons why designers use this design,
        > mostly around the fractional rigs but it got me thinking about Catalina
        > using the swept back spreaders (w/ the upper stays) to help introduce
        > per-bend on this boat. With my spreaders having "play", I'm starting to
        > think that if the (my) Spreaders are not rigid to the mast, it would not
        > matter how much stay tension I would apply, the spreaders would not be able
        > to do their job and introduce any bend. Am I correct in thinking this? I
        > have also noticed that with the other three C26's at the marina, every Capri
        > has different configuration for attaching the spreaders to the mast. On my
        > capri (see attachments), I basically have a tee-bar riveted to the mast and
        > the spreader slides over the bar with a pin to attach the arm to the bar. I
        > wish I had the mount of another C26 owner at the lake in which his spreaders
        > fit into a "sleeve" mount which in returns, does not allow the end of the
        > spreader to have any horizontal movement. I would love to hear the groups
        > opinion on this topic and the effect of the spreaders on pre-bend and if the
        > spreaders should have any horizontal play.
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        >
        > Cheers
        >
        > Stephen
        >

        No virus found in this message.
        Checked by AVG - www.avg.com
        Version: 2013.0.2805 / Virus Database: 2637/5968 - Release Date: 12/18/12
        Internal Virus Database is out of date.

      • Stephen M. Hollingsworth
        Leighton The original specs call for 3” of rake and only 1.5” of pre-bend. Do you have yours set for 3”? I also have a new Main from North and asked that
        Message 4 of 4 , Dec 27, 2012

          Leighton

           

          The original specs call for 3” of rake and only 1.5” of pre-bend. Do you have yours set for 3”?

           

          I also have a new Main from North and asked that exact question a few months ago. They do cut the main based on the Catalina specs but my rep unfortunately could not tell me the specs. If memory serves me correctly, we had this discussion once before, if or when I ever order a new main, I would highly consider reducing the camber by a few percentage points. I’m just not happy with the cut of the North Main and I’m hoping it’s due to the fact that I can’t introduce any pre-bend on the rig.

           

          Unfortunately, I cannot say if my spreaders ever fit snug against the spreader base/mast but from the inspections that I have done, I cannot see how they ever did, even with the wearing on the front edge of the spreader base. I’m wondering what type of spreader base that you have because it appears that Catalina produced a few different versions (based on the observations of the four C26’s at our marina).

           

          Like I mentioned in the thread, some of the play is also contributed to the slight wallowing out of the pin hole over age. I can also tell you that since I have owned the boat (going on 7 years), the mast has always been tuned to the Catalina specs (good or bad) and maybe that’s been the problem all along. Have I been applying to much tension on the lowers like Brion Toss has indicated (for how the boat was designed and the placement of the chainplates)? I’m starting to think that I have been!

           

          Anyway, I just wanted to share this exchange with Brion and hopefully it will help others have a better understanding of our rigs. It has clearly helped me understand the dynamics more and I cannot agree more with you, if you can have an expert look at you rig, I would highly suggest it. I had a professional look at mine this November and it inspired me to do allot more research.

           

          A split backstay? what a NICE upgrade!

           

           

          Smh

           

          From: capri26@yahoogroups.com [mailto:capri26@yahoogroups.com] On Behalf Of Leighton Westlake
          Sent: Thursday, December 27, 2012 3:51 PM
          To: capri26@yahoogroups.com
          Subject: RE: [capri26] Re: Pre Bend

           

           

          The mast is designed for a 3-inch pre-bend.  Otherwise the mainsail will not fit correctly and it will bag in the center.  If you order a new main (As I did from North) it will come cut for a pre-bend as that is the specification from Catalina.

           

          The spreaders should be tight to the mast and the stays tensioned properly.  Obviously the spreaders and the stays  were not tensioned correctly and it allowed for play in the mast that led to the spreader damage. 

           

          Mine has a new rig professionally installed and the pre-bend (Goes faster by ½ knot at least and no back-winding of the main.) is there allowing the proper tensioning of the stays.  Of note we did eliminate the offset backstay for a split design that allowed for equal tensioning of the upper and lower stays and also has provision for a backstay tensioner - if I ever really wanted one.

           

          If you have any questions, please feel free to contact me.

          Signature-LDW

          Leighton Danis Westlake, Jr., PE, PLS

          Principal Engineer

          a division of DANIS LOGO

          10175 Flag Dr, Palm Beach Gardens, FL 33410-4775           

          Tel:  561-799-5280                                                                                                      

          Fax: 561-799-5776                                                                                                       )

          Cell: 561-222-0714

          email: leighton@...

           

          Privilaged Correspondence

           

          This e-mail and any attachments are intended only for the named recipient(s) and may contain information that is legally privileged, confidential, or exempt from disclosure under applicable law. If you have received this message in error, or are not the named recipient(s), you may not retain copy or use this e-mail or any attachment for any purpose or disclose all or any part of the contents to any other person. Any such dissemination, distribution or copying of this e-mail or its attachments is strictly prohibited. Please immediately notify the sender and permanently delete this e-mail and any attachment from your computer.

           

           

          From: capri26@yahoogroups.com [mailto:capri26@yahoogroups.com] On Behalf Of Stephen
          Sent: Thursday, December 27, 2012 4:38 PM
          To: capri26@yahoogroups.com
          Subject: [capri26] Re: Pre Bend

           

           



          Happy Holiday's Everyone.

          I just wanted to follow up with everyone and share a discussion that I had with a Brion Toss, a very well respected rigger. The link to the forum discussion is below.

          http://www.briontoss.com/spartalk/showthread.php?t=2340

          Cheers
          Stephen

          --- In capri26@yahoogroups.com, "Stephen M. Hollingsworth" <smh@...> wrote:
          >
          > First, Art great job on the Mainsheet article on Pre-Bend, it could not have
          > come at a better time for me. Myself and the other C26 owner's at the
          > marina have been wrestling with this issue for years with limited success,
          > so I was glad to see the article.
          >
          >
          >
          >
          >
          > Now, I realize that we have discussed the Pre-Bend issue before and
          > Catalina's recommended solution that involves using a shim plate but I had
          > an incident last winter with my mast that got me rethinking the whole issue.
          > Long story short, last spring, I had my mast off the boat and sitting on
          > horses when some highs winds caused my mast to fall and land on its
          > spreaders. There was no physical damage to the mast but after examining the
          > spreaders, I noticed that they had some horizontal play (3" from front to
          > back) but I just contributed the extra play from the years of the pin hole
          > being slighting wallowing out from age. With that all said, the question I
          > have is on Catalina's intent or purpose for the swept back spreaders on the
          > C26's. I know of all the typical reasons why designers use this design,
          > mostly around the fractional rigs but it got me thinking about Catalina
          > using the swept back spreaders (w/ the upper stays) to help introduce
          > per-bend on this boat. With my spreaders having "play", I'm starting to
          > think that if the (my) Spreaders are not rigid to the mast, it would not
          > matter how much stay tension I would apply, the spreaders would not be able
          > to do their job and introduce any bend. Am I correct in thinking this? I
          > have also noticed that with the other three C26's at the marina, every Capri
          > has different configuration for attaching the spreaders to the mast. On my
          > capri (see attachments), I basically have a tee-bar riveted to the mast and
          > the spreader slides over the bar with a pin to attach the arm to the bar. I
          > wish I had the mount of another C26 owner at the lake in which his spreaders
          > fit into a "sleeve" mount which in returns, does not allow the end of the
          > spreader to have any horizontal movement. I would love to hear the groups
          > opinion on this topic and the effect of the spreaders on pre-bend and if the
          > spreaders should have any horizontal play.
          >
          >
          >
          >
          >
          >
          >
          >
          >
          >
          >
          > Cheers
          >
          > Stephen
          >

          No virus found in this message.
          Checked by AVG - www.avg.com
          Version: 2013.0.2805 / Virus Database: 2637/5968 - Release Date: 12/18/12
          Internal Virus Database is out of date.

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