Page 1 of 2 12 LastLast
Results 1 to 10 of 14
  1. #1
    New Member
    Join Date
    Jan 2012
    Location
    Ruston, La
    Posts
    3

    Eliminating the Weak Spot - Whoopie Slings

    I'm new to the forum, but I've dived headfirst into hanging and diy'd my whole set up so far. The one piece that's stuck in my head is the whoopie sling. It's simple, but manages to do something that could easily be overcomplicated with other methods. That being said I do see that it could be improved slightly by eliminating the weak spot that lies between the two buries. It's the only part on the sling that isn't doubled up in some way.

    My idea is simply to overlap the buries. The adjustable bury would simply come out of the line some distance past the end of the bury for the eye. The two inner lines run beside each other not through one another.

    I've just done this with some mason line, and it's still easy to adjust. I don't see any issue with this on small line. The thing I'm most curious about is if two pieces of amsteel will fit inside the other part and still function. There's also the possibility that this much material will weaken the line to the point that this isn't a useful method.

    If this were to work in theory it may be worth trying on smaller line than usual since it will increase the breaking strength. That might eliminate some of the issues with the larger line.

    I also think that if I can figure out how to bury part of the adjustable bury inside of the fixed bury(don't ask me how) it may work better and possibly eliminate the need for the locked-brummel at the eye splice. That will be a bury in a bury. We'll call it whoopie-ception or something.

    I think that's all I had to say. Chime in with comments and whatnot. The one I've already made is going to stay that way. Another is on the way for some unscientific testing.

    Oh, if this doesn't make sense then let me know. It's late.

  2. #2
    Senior Member GrizzlyAdams's Avatar
    Join Date
    Apr 2007
    Location
    Illinois
    Hammock
    GrizzBridge Ariel
    Tarp
    HG Cuben Winter
    Insulation
    DIY UQ
    Posts
    4,777
    Images
    564
    I understand the idea, I think.

    Tension is what keeps the fixed eye bury from moving when under load. The locked brummel keeps it from pulling out when not under load....but, significantly perhaps, under the assumption that the buried line is left alone inside the cord.

    If you overlap the buries, then as you shorten the whoopie sling, the sliding of the sling loop against the the fixed eye bury will....I dunno. Seems like it would encourage that bury to back out a bit. Not liking that prospect.

    I don't overlap the buries, but I do have the exit point of the adjustable line right at the point where the fixed eye bury ends, not so much as to "minimize the weakest point" as to minimize the shortest length the whoopie sling can span.

    just my $0.05 on the question...
    Grizz
    (alias ProfessorHammock on youtube)

  3. #3
    New Member
    Join Date
    Jan 2012
    Location
    Ruston, La
    Posts
    3
    Quote Originally Posted by GrizzlyAdams View Post
    I understand the idea, I think.

    Tension is what keeps the fixed eye bury from moving when under load. The locked brummel keeps it from pulling out when not under load....but, significantly perhaps, under the assumption that the buried line is left alone inside the cord.

    If you overlap the buries, then as you shorten the whoopie sling, the sliding of the sling loop against the the fixed eye bury will....I dunno. Seems like it would encourage that bury to back out a bit. Not liking that prospect.

    I don't overlap the buries, but I do have the exit point of the adjustable line right at the point where the fixed eye bury ends, not so much as to "minimize the weakest point" as to minimize the shortest length the whoopie sling can span.

    just my $0.05 on the question...
    Thanks for your input and your videos! Those videos really pulled everything together in my initial state of confusion.

    I don't disagree with your concern about the adjustment messing with the fixed eye bury. I had thought about it and decided it would make it self evident at some point before I start doing this on a scale that would risk my butt.

    I also made another from mason line, and broke it. It certainly felt more difficult to break, and broke in the loop. Seems as though it works to some extent.

  4. #4
    Senior Member
    Join Date
    Jan 2011
    Location
    IN
    Hammock
    WBRR, Lots of DIY
    Tarp
    MacCat; Cloudburst
    Insulation
    Lynx, HG T/UQ, AHE
    Suspension
    Varies
    Posts
    8,464
    Quote Originally Posted by jrh065 View Post
    ...by eliminating the weak spot that lies between the two buries. It's the only part on the sling that isn't doubled up in some way...
    By my understanding, the area of single line is not the weakest point in a whoopie. It is the distorted area of the constrictor where the free end of the adjustable bury exits the constrictor. Overlapping the buries would further stress this area making it even weaker.

    Again...this is my understanding, but I am fairly confident it is correct.

  5. #5
    Senior Member
    Join Date
    Jan 2011
    Location
    IN
    Hammock
    WBRR, Lots of DIY
    Tarp
    MacCat; Cloudburst
    Insulation
    Lynx, HG T/UQ, AHE
    Suspension
    Varies
    Posts
    8,464
    FWIW...

    "Test samples were consistent for breaking strengths and exhibited a single failure mode. The Whoopie Sling broke at the exit point of the adjustable tail with the butt splice."

    Quoted from this paper.

  6. #6
    Senior Member GrayDog's Avatar
    Join Date
    Jan 2010
    Location
    Orlando, FL
    Hammock
    Skeeter Beeter Pro
    Tarp
    WB Mamajamba
    Insulation
    WL3/4 - GoLite TQ
    Suspension
    Whoopies
    Posts
    358
    Images
    8
    If break strength is your concern, why not go with a larger diameter amsteel?

    Just moving from 7/64" to 1/8" increases break strength from 1600# to 2500# with weight only increasing from 4.8oz/100ft to 8oz/100ft.
    hammock [ham-uhk] noun
    Man's successful attempt to sleep on a cloud

  7. #7
    Senior Member JerryW's Avatar
    Join Date
    Jul 2009
    Location
    West Central Illinois
    Hammock
    DIY Bridge
    Tarp
    DIY Hex/Grizz Beak
    Insulation
    DIY UQ and TQ
    Suspension
    Whoopie Slings
    Posts
    1,143
    Images
    101
    I believe you are over-thinking the whoopies. Even using Dynaglide, the single portion is strong enough to support a huge load. If you're really worried, just follow GrayDog's suggestion above.


    Jerry
    The "Search" function is your friend!

  8. #8
    Senior Member SmokeBait's Avatar
    Join Date
    Sep 2009
    Location
    Defiance, Missouri
    Hammock
    Warbonett BB 1.1 DL
    Tarp
    BWDD Winter Dream2
    Insulation
    Winter Crowsnest
    Suspension
    whoopieslings.com
    Posts
    1,337
    What Grizz says...

  9. #9
    Senior Member Rain Man's Avatar
    Join Date
    Nov 2007
    Location
    Nashville, TN
    Hammock
    Hammeck Netty
    Tarp
    HG dyneema/MacCat
    Insulation
    DIY UQ and UGQ TQ
    Suspension
    whoopie slings
    Posts
    2,907
    Images
    8
    Quote Originally Posted by GrayDog View Post
    If break strength is your concern, why not go with a larger diameter amsteel?

    Just moving from 7/64" to 1/8" increases break strength from 1600# to 2500# with weight only increasing from 4.8oz/100ft to 8oz/100ft.
    Many of us do just that. Matches the safety margin professional riggers go by. 10-to-1. With no weight cost to speak of.

    Quote Originally Posted by gmcttr View Post
    By my understanding, the area of single line is not the weakest point in a whoopie. It is the distorted area of the constrictor where the free end of the adjustable bury exits the constrictor. Overlapping the buries would further stress this area making it even weaker.
    You beat me to it. I also think it might actually make the whoopie weaker to overlap those buries, not stronger.

    Rain Man

    .
    "You can stand tall without standing on someone. You can be a victor without having victims." --Harriet Woods

    http://www.MeetUp.com/NashvilleBackpacker
    .

  10. #10
    Senior Member Knotty's Avatar
    Join Date
    Mar 2009
    Location
    Denville, NJ, USA
    Hammock
    DIY Stretch-Side
    Tarp
    DIY Cat Cut Hex
    Insulation
    Phoenix and Nest
    Suspension
    cinch buckles
    Posts
    4,377
    Images
    227
    The weak point is the exit of the adjustable bury, as documented in an email to me by a Samson Rope R&D Engineer.

    Overlapping the two buries may create an uneven transition area, which will weaken the rope at that point. That's why the fixed bury has to be tapered. Cutting it off flush creates a localized load.
    Knotty
    "Don't speak unless it improves the silence." -proverb
    DIY Gathered End Hammock
    DIY Stretch-Side Hammock
    Stretch-Side "Knotty Mod"
    DIY Bugnet

  • + New Posts
  • Page 1 of 2 12 LastLast

    Similar Threads

    1. Weak spot in DIY Tablecloth hammock?
      By alexpotato in forum Do-It-Yourself (DIY)
      Replies: 5
      Last Post: 08-19-2013, 21:58
    2. SOLD: Whoopie hooks on Whoopie Slings
      By harleynemo in forum [SOLD/WITHDRAWN] Items no longer available
      Replies: 5
      Last Post: 12-29-2012, 12:50
    3. To buy Whoopie Slings, Or not to buy Whoopie Slings
      By HHanginrookie in forum Suspension Systems, Ridgelines, & Bug Nets
      Replies: 13
      Last Post: 07-12-2012, 09:07
    4. Eliminating Carabiner from Whoopie/Treestrap Setup: New Hardware Idea - DUTCH?
      By thesergeant in forum Suspension Systems, Ridgelines, & Bug Nets
      Replies: 17
      Last Post: 05-30-2012, 20:52
    5. Whoopie slings on the way
      By GGT in forum Suspension Systems, Ridgelines, & Bug Nets
      Replies: 9
      Last Post: 02-17-2011, 15:14

    Tags for this Thread

    Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •