Whoopie Sling Suspension

[Frawg]

Okay, I got the 'kids' tucked in and the sky was clear....

TeeDee, re the picture you referenced:

The left side UCR measured 38.5", toggle to toggle. The tree strap measured 7.5" from the limb to the toggle.

The right side UCR measured at 68.5", toggle to toggle. The porch side strap measured 9.5" from pillar to toggle.

The ridge line measured 98.5". My end channel loops are shorter than I'd played with before, but I also have a little more sag than usual at the moment.

Distance between the pillar and the limb is about 195" -- 6-1/2 steps based on a 30" nominal stride. (I marched a lot in college)

Height of the limb is about 70"; height of the strap at the pillar is about 77". (guestimated; I'm 74" tall).

The ridge line is also essentially level.

I believe that, with gravity as a constraint, establishes the geometry. I can get more precise later if you need that level of detail.

HTH

[TeeDee]

.....

What's in the picture are actually UCRs and are 12' long from fixed eye to toggle, fully extended. Obviously they aren't fully extended in the picture, but I'll have to measure them for you later.

If I'm understanding the UCR method correctly, then the UCR method incorporates two sections with one section buried in the other. one section ends in the fixed eye and the opposite end of the other section ends in the toggle. The other end of each section also then has a short piece past the bury that is essentially what I term "dead rope", i.e., serves no purpose other than terminating the rope.

What is the length of "dead rope" that you use?

And how much rope do you use for the bury? Not how long the bury is after buried, but how much do you measure of the un-spliced rope for the bury. When the bury is accomplished, this section of the rope is significantly shorter. In measuring the length of rope needed, the original length must be used.

I'd imagine the fixed overhead to be less for a whoopie sling, since it can use a shorter bury than the UCR can, with a difference I'd posit as something around a foot or less. Call those Lw,min and Lu,min respectively.

If we call the amount of variable line L, then the UCR can span a range from Lu,min to Lu,min+L.

The range that the whoopie sling can span depends on the displacement between its bury and its fixed eye. If that distance is 'B', then the amount of line left for free play is L-B and the whoopie sling will span the distance from Lw,min+B to Lw,min+B+(L-B)/2.

I construct my Whoopie Slings with B zero.

The above are correct, but what I really wanted to compare was the length of rope needed to construct your UCR end for the suspension.

Essentially what I wanted to compare was the length of rope you start with to construct the UCR for one end. For the UCR, this then gets cut into 2 sections, which are probably not of equal length.

The UCR can definitely handle a greater tree span for a given rope length since it doesn't have to double. But as you state the UCR needs a longer bury to handle the loads and then you have the "dead rope". Also, If I'm reading what you are doing correctly you also need two knots to finish things off (is this correct?). The length needed for the knots must also be included in the needed rope length.. I am currently using the Samson Ropes directions on the Whoopie Sling adjustable bury and their directions for the eye splice (both interpreted correctly now I believe ) and the rope needed for a bury is 9.6" which yields and finished bury length of 8". That is for both the fixed eye splice and the adjustable bury, which yields a finished bury total of 16" with 0" between eye bury and adjustable bury.

I've completed my suspension triangle alterations and have used a modified Whoopie Sling. It has an adjustable loop on each end. I use a 10' piece of AS-78. The adjustable loops are threaded through fixed eyes on the rope ends coming from the arcs. This gives me the ability to quickly and easily adjust the suspension triangle sides from approximately 23" out to approximately 36". I started with 10' and haven't shortened the length yet, but since I never use more than approximately 28" for the side of the suspension triangle, I could cut a fair amount off each end. I'll wait until I'm sure before cutting though.

So far, I really like the set-up. Before I used toggled Zeppelin Bends on the suspension triangles and setting and then changing the side length was a tedious process of tying, hanging, lying in the hammock to pull the knots tight and then adjusting the knots to get the desired lengths. Tedious.

With the 2 adjustable loops, setting the length and then adjusting it later is easy and quick and I don't have to redo after lying in the hammock since the bury splices used for the adjustable loops don't change the length like knots do when pulled tight. I put marks on the adjustable loops so that I can read the length of the suspension triangles directly off the loop.

[Scratch]

Wow ... I made my first miniature whoopie sling! The wife thinks I'm nuts! (though probably not because of the whoopie sling ) I only used a couple feet of 1/8" Amsteel blue. The instructions made it easy to follow. Took maybe 15 min. Thanks SlowBro!

[amac]

***deleted, I accidentally posted this in the wrong thread ***

[SlowBro]

Wow ... I made my first miniature whoopie sling! The wife thinks I'm nuts! (though probably not because of the whoopie sling ) I only used a couple feet of 1/8" Amsteel blue. The instructions made it easy to follow. Took maybe 15 min. Thanks SlowBro!

Glad this is useful. I found this splicing to be a fun project and the fact that it might even be useful is frosting on the cake. It will be interesting to get feed back from hangers using this suspension to see how it fares.

-SlowBro

[fin]

This thread is just too cool. I have to try this.

[Frawg]

If I'm understanding the UCR method correctly, then the UCR method incorporates two sections with one section buried in the other. one section ends in the fixed eye and the opposite end of the other section ends in the toggle.

Right. ZA206 calls them a static section and the constrictor section. The static section is buried inside the constrictor. I put a fixed eye on the static section, toward the tree. I put my toggle in a slipped eye at the hammock end of the constrictor section. That way all my adjusting is done close to the hammock, and I can use any extra length of static section for a drip loop.

The other end of each section also then has a short piece past the bury that is essentially what I term "dead rope", i.e., serves no purpose other than terminating the rope.

The one on the static section also functions as a stopper, preventing the static part from slipping out of the constrictor section.

What is the length of "dead rope" that you use?

I terminate each of those ends with a back splice for neatness, using between 2 and 3 inches to make each one. I suppose I could save a little line if I just tied an overhand stopper and melted the ends instead.

On the toggle end of my latest constrictor section I left about 1" between the constriction bury and the bury of the slipped loop that holds the toggle. The slipped loop, its bury and its end splice took another 3 or 4 inches. On the constrictor's other end I use another 6" for the back splice and enough line to form a rolling hitch.

And how much rope do you use for the bury? Not how long the bury is after buried, but how much do you measure of the un-spliced rope for the bury. When the bury is accomplished, this section of the rope is significantly shorter. In measuring the length of rope needed, the original length must be used.

Is this a test? Actually, I eyeballed it to get the 14 inches I ended up with on the latest constrictor. Let me do a quick test bury.... Okay, I'm back. A 12" initial section yields a 9.5" completed bury, so my 14" finished bury must have required an 'original length' of just under 18" - probably somewhat less, actually, because my test bury would probably measure a bit longer than 9.5" under full load.

...what I really wanted to compare was the length of rope needed to construct your UCR end for the suspension.

Oh...

Constrictor section: 3" to 4" (say, 3.5"?) for the slipped loop, 1" of dead space, 18" for the (~14") bury and 6" for the rolling hitch and its back splice. Total cut length = 28.5", give or take.

Static section: The length you want to span + 6" (for the doubled back part of the eye splice) + 3" (for the back splice at the other end) - 2" (contributed by the toggle end of the constrictor). For a 12' finished UCR, the static line cut length = 144" + 6" +3" - 2" = 151", give or take.

Total cut length for a 12' UCR = 28.5" + 151" = 179.5", give or take.

Essentially what I wanted to compare was the length of rope you start with to construct the UCR for one end. For the UCR, this then gets cut into 2 sections, which are probably not of equal length.

Looks like it takes about 15' of line to make a UCR that can cover up to 12'.

So far, I really like the set-up. Before I used toggled Zeppelin Bends on the suspension triangles and setting and then changing the side length was a tedious process of tying, hanging, lying in the hammock to pull the knots tight and then adjusting the knots to get the desired lengths. Tedious.

Nice improvement!

With the 2 adjustable loops, setting the length and then adjusting it later is easy and quick and I don't have to redo after lying in the hammock since the bury splices used for the adjustable loops don't change the length like knots do when pulled tight. I put marks on the adjustable loops so that I can read the length of the suspension triangles directly off the loop.

Nicely done! I find that the way I feel varies from day to day so my preferred sag varies a little, correspondingly. What I like is the ability to fine tune settings on the fly. I need to play a bit more with my head/foot tilt scheme, but even just eyeballing things my initial setup is seldom far off so I usually just need to do some minor tweaking.

I've pretty much reached the "good enough" stage on this, I think. Time to start debugging my bug netting setup.

[Coldspring]

This thread has given me a headache!

Since I'm a lazy stooge...is there someone that is making these for the less mechanically inclined.

I want one for my Blackbird, to replace the strap system. It sure would be easier for someone to build one out of the materials they have on hand, and SELL IT to me.

[UncleMJM]

Once Coldspring's order is filled, I am up for a set too.

[Frawg]

Coldspring & UncleMJM -

I believe ZA206 said he makes UCRs and whoopie slings as a side business, so you might PM him.

I and others could certainly make something, as well, but I personally don't know how to attach them to the WB or HH. Seems to me you'd have to handle that yourself, anyway, and making a UCR or a sling surely couldn't be much harder than reworking the hammock attachment.

If you can't get someone else to do it for you, PM me and I'll do what I can. I just wouldn't want to get you halfway there and leave you (not) hanging.

Chuck