Dynaglide Whoopies

[opie]

I was there and it is true. I myself hung from 7/64 dynaglide the same night and I weigh in just over 200 lbs. This stuff it tough.

Did you mean 7/64 dynaglide? Is there such?

The Dynaglide is 2mm, while the 7/64 Amsteel is 2.5mm, or therabouts.

[opie]

Opie im considering making some, what would you say the weight savings are vs 7/64 amsteel at 9 foot lengths? just a guess would suffice. BTW do you remember how big the dg we did in the group buy was, was it 7/64, cause if so, thats what i have, in orange.

It should be 2mm. Some vendors have it labeled as 1.8mm. But I believe its all 2mm.

[SGT Rock]

It should be 2mm. Some vendors have it labeled as 1.8mm. But I believe its all 2mm.

I was looking at a site thinking about getting some for bear bagging. It was listed as 1.8mm but 1000lb capacity like your stuff. So this is probably the same material?

[opie]

To be clear, I have no axe to grind here; I'm simply giving notice for those who might be unaware.

So, lets put 300 in the hammock. Now assume, for whatever reason, that it gets hung at 20° instead of the recommended 30°. That gives a *static* load of 439 on each side.

It's easier to bounce a bit when moving around (changing position, adjusting bedding, &c.), especially with so much weight. This *dynamic* loading can be more or less, but lets call it double: a static load of 300 becomes 600 in dynamic loading, 877 on each side.

Dynaglide (*when new*) has an *average* breaking strength of 1000 but *minimum* breaking strength is 90%. Assuming the cord has no defects and uses only careful splices (no knots, marlin spike hitches, or other sharp bends), breaking strength is further reduced by 80% for a Whoopie Sling according to Samson but lets say it's as good as 95% anyway: an average breaking strength of 1000 yields a minimum of 900 with splice reduction to 855.

877 > 855

There are many reasons (not just liability) to use a significant safety factor.

In any case, do as you will; it's good to test things!

My safety factor is a 250 pound limit. I.E. I wont sell them to you if you weigh more. I believe this is in the first post of this thread.

So far what Im getting for an average weight is 150# for folks that purchase the DG for slings.

Again, thanks for your concern.

[opie]

I was looking at a site thinking about getting some for bear bagging. It was listed as 1.8mm but 1000lb capacity like your stuff. So this is probably the same material?

Should be, yes.

[RePete]

Just went back and looked at the group buy listing and Opie did list it as 2 mm. Not sure where I got the 7/64 number from. This stuff is even smaller and tougher than I thought.

[Albert Skye]

My safety factor is a 250 pound limit. I.E. I wont sell them to you if you weigh more. I believe this is in the first post of this thread.

That post is 2 months old. And this newer one seems to imply a 300 pound limit.

Anyway, replacing 300 with 250 in my previous illustration brings the load on each line to 731, and if we *do* use Samson's 80% reduction for Whoopie Slings, minimum breaking strength is 720.

[opie]

That post is 2 months old. And this newer one seems to imply a 300 pound limit.

Anyway, replacing 300 with 250 in my previous illustration brings the load on each line to 731, and if we *do* use Samson's 80% reduction for Whoopie Slings, minimum breaking strength is 720.

Yes.. I said 300 in the post you just linked to. My mistake. I stand by 250.

720 is well below the 930 the ones I tested failed at.

You must keep in mind the minimum breaking strength that manufacturers put out is very conservative. For liability reasons.

Much the same reason I put a 250 limit on a DG sling, for liability reasons.

Then there is the real world result of a set of DG slings holding me up... 265#, bouncing around creating dynamic loading. They have held me in both a DIY and a BMBH.

While I agree with you that a certain amount of common sense must be put into place when pushing the design limits of a given product. Please dont assume I havent given proper thought to offering those products for sale. Everything I sell I have tested. Not just with me physically trying them out, but also pulling them apart. Yes sometimes things get past me like the original toggled TRL where the line toggle was to short.

It appears that most of the folks that have replied to this thread are all under 200. Closer to 150.

Im bad at math, can you do your calcs using what the actual weights are of the members using them?

[Schneiderlein]

Anyway, replacing 300 with 250 in my previous illustration brings the load on each line to 731, and if we *do* use Samson's 80% reduction for Whoopie Slings, minimum breaking strength is 720.

In your previous post, you also assume that you hang at an angle of 20º and that you can double the load by a bit of bouncing. The minimum breaking strength of 720 lbf you assume now is at odds with opie's testing.

From what I have read here on HF, and from my personal experience, a lot of people have used ropes with breaking strengths between 1,000 and 2,000 lbf for a long time. And everybody, including myself, used some sort of knot before splicing became all the rage. I am convinced that these suspensions had a lot lower failure loads than the Dynaglide whoopies due to all the knots that were used.

[SGT Rock]

You must keep in mind the minimum breaking strength that manufacturers put out is very conservative. For liability reasons.

Much the same reason I put a 250 limit on a DG sling, for liability reasons.

And when it comes to customers like me (and I imagine some others here) - when I order something like this I understand there is no warranty given or implied. It's pushing the limits, so I take a chance I could brake a sling and fall 18" on my ***. It wouldn't be the first time. It isn't like I am going to hang over the Grand Canyon with one.