Page 1 of 2 12 LastLast
Results 1 to 10 of 20
  1. #1
    Senior Member Timberrr's Avatar
    Join Date
    Jan 2011
    Location
    On the road - fulltime RVing
    Hammock
    WBRR
    Tarp
    UGQ Winter Dream
    Insulation
    UGQ TQ and UQ
    Suspension
    Straps, D. Buckles
    Posts
    1,687
    Images
    13

    Engineers, start your engines!!

    I need a horizontal bar that is strong enough to a hammock from each end. Basically, you have two of these bars, each attached to, or suspended from a tree (somehow). Then you would hang two hammocks between them.
    One of the possible materials for the bars is carbon fiber. Which I know close to absolutely nothing about. Here's a spec sheet. Does this say it could withstand the various dynamic forces? What do you think?

    http://www.rockwestcomposites.com/ck...pdf?1340058755

    I tried to insert a pdf but it didn't work. Sorry.
    How 'bout now?
    Nope, still didn't work.
    Attached Files Attached Files
    HangCon Sign Up:
    https://docs.google.com/spreadsheets...it?usp=sharing

    So many trees, so little time...


  2. #2
    Senior Member ahhhgladius's Avatar
    Join Date
    Aug 2012
    Location
    sumter
    Hammock
    eno double nest, 12'r, 90x132"r
    Tarp
    kelty noah 12 :D
    Insulation
    DIY down and VB
    Suspension
    cinch/whoopie
    Posts
    376
    illustration please?
    Glory to the Fallen, Honor to the Lost. Faith to the Missing. Carry on Forever.

  3. #3
    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 are kind of an engineer, but there's a verb missing or something in your description, so I'm not entirely sure I grok your problem.

    I'm gonna guess...you want to hang two hammocks side-by-side, off the same pair of trees, but separate them. So you're thinking some kind of spreader bars that would push the suspension lines of the two hammocks apart.

    I'm thinking maybe somebody has done this already. I think you need only separate the two hammocks at the head, the two hammock occupants can play footsies with each other OK. The compression forces on that bar would be a function of the weights, the length of the suspension triangle from the bar to the tree. Thumbnail sketch, twice the compression force you have on spreader bars for a bridge hammock, since there is twice the weight.
    Grizz
    (alias ProfessorHammock on youtube)

  4. #4
    Senior Member Timberrr's Avatar
    Join Date
    Jan 2011
    Location
    On the road - fulltime RVing
    Hammock
    WBRR
    Tarp
    UGQ Winter Dream
    Insulation
    UGQ TQ and UQ
    Suspension
    Straps, D. Buckles
    Posts
    1,687
    Images
    13
    @Grizz

    Yes. Your thinking is correct. Mostly.
    Here's what I'm still going after.
    http://www.hammockforums.net/forum/s...ad.php?t=35582
    As you can tell from the date of the thread, this is a work in progress.

    Thanks for your insights.
    I know from previous failures that there is much more than compression on the bar. I had a bar of 1.25" dia. poplar give way slowly and finally break on the third night.
    HangCon Sign Up:
    https://docs.google.com/spreadsheets...it?usp=sharing

    So many trees, so little time...


  5. #5
    Senior Member streamline's Avatar
    Join Date
    May 2010
    Location
    Greenville, SC
    Hammock
    diy HH
    Tarp
    10' x 8' diy cat
    Insulation
    Full down UQ
    Suspension
    Whoopies w/ straps
    Posts
    355
    People use trekking poles for this. Don't put the pole at the tree though, put it at the ends of the hammocks.

  6. #6
    Senior Member TFC Rick's Avatar
    Join Date
    Jul 2010
    Location
    Jacksonville, Florida
    Hammock
    DW netless/JS Full net
    Tarp
    Hex
    Insulation
    HG Incubator 40
    Suspension
    Dutch buckle/strap
    Posts
    1,511
    Tim is this hiking based or for your boat trips? Would pipe work? Obviously heavy as sin but stout enough to accomplish the deed?
    Look up before you hook up!!
    Originally Posted by body942
    Me big. Me like hammockgear burrow. Long. Problems no. People good.

  7. #7
    New Member Dustb2000's Avatar
    Join Date
    May 2012
    Location
    Brandon, MS
    Hammock
    DIY WBBBB
    Tarp
    DIY Hex Tarp
    Insulation
    DIY 3/4 Insultex
    Suspension
    Webbing/Whoopies
    Posts
    39
    Images
    13
    If your goal is to hang two hammocks just using two trees I've had success using the following method:



    Basically just took a 1" x 2" x 18" board and drilled a hole in each end to run the suspension to for one end.

  8. #8
    Senior Member Jayson's Avatar
    Join Date
    Dec 2011
    Location
    Ontario
    Hammock
    1.9oz DIY
    Tarp
    Superfly
    Insulation
    Down
    Suspension
    DIY UCR
    Posts
    1,243
    I have used my hiking poles to do this many times with my wife. They are cheapy twist lok poles and they held just fine. As was said just put them as close to the ends of the hammock as you can.
    No worries.

  9. #9
    Senior Member Detail Man's Avatar
    Join Date
    Aug 2010
    Location
    Knoxville, TN
    Hammock
    DIY or Bonefire Whisper
    Tarp
    DIY Silpoly
    Insulation
    Incubator, Burrow
    Suspension
    Bonefire Deluxe
    Posts
    889
    Images
    5
    Timberr, I'm assuming you want to use the spreader bars with your Chrysallis bridge hammocks. The spreader bars will function best at the end of each hammock, rather than at the tree. The forces on the spreader bar will be less at the hammock ends. If you try to put them at the tree, as in your diagram, the forces will be much greater, hence the poplar dowels failing.

    The downside to having the bars at the hammock ends is that one occupant transfers his/her motion to the other hammock. Once both occupants are settled in, it's no big deal in my experience.

    To place the spreader bar at the tree, the bar will need to be able to withstand lateral stress more so than compression. Tubing tends to withstand these forces better than solid material The thicker the wall thickness of the tubing, the stiffer the tubing will be.

    Carbon fiber withstands compression quite well, but I'm not sure it would hold up to the lateral forces involved if placed at the tree.

  10. #10
    Member
    Join Date
    Aug 2012
    Location
    MidWest
    Hammock
    DL 1.4 ripstop gathered end
    Tarp
    8x10 flat silnylon
    Insulation
    Down
    Suspension
    whoopie/shackle
    Posts
    73
    I'd probably go with titanium as it's much more forgiving to torque yet still very light.
    When torque is applied to Aluminum poles they bend and carbon shatters but titanium will revert back into it's original shape afterward.

    Ti poles will likely run you about the same as carbon would.

    If you use trekking poles that's definitely the way to go though.

    Another consideration would be to use 4 guy lines and stakes to pull the hammocks apart. Would be lighter and cheaper but some people like to swing so maybe that's not ideal for you.
    Last edited by jordo_99; 01-30-2013 at 12:33.

  • + New Posts
  • Page 1 of 2 12 LastLast

    Similar Threads

    1. Engineers can you help?
      By easyriver in forum Do-It-Yourself (DIY)
      Replies: 14
      Last Post: 09-02-2011, 12:40
    2. Blackbishop Help - Engineers Needed
      By StumpJumper in forum Do-It-Yourself (DIY)
      Replies: 10
      Last Post: 07-24-2010, 21:35
    3. Again, question re: cleats for the Engineers, also old yellow
      By BillyBob58 in forum Suspension Systems, Ridgelines, & Bug Nets
      Replies: 0
      Last Post: 08-15-2007, 16:39
    4. Cleat/Hitchcraft question for the engineers
      By BillyBob58 in forum Suspension Systems, Ridgelines, & Bug Nets
      Replies: 13
      Last Post: 08-04-2007, 11:51
    5. Start your kids hammocking from the start
      By Coffee in forum General Hammock Talk
      Replies: 2
      Last Post: 10-29-2006, 13:36

    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
    •