I have been wanting to make an ergo hammock for a while but I have found no real plans or dimensions. All I have found is this video, it is the 3rd one down.
https://www.hammockforums.net/forum/...ad.php?t=46288
My plan is to use a 30" pad in a sleeve. The overall width can be up to 60" and the length can be anything under 118"
If anyone has any experience or ideas would be keen to hear.
Good for you! I have adjustable strings on the ends of some of my hammocks, and I started a right-angle hammock a couple of years ago that I mean to get back to. I see in the video that the shroud lines are attached to webbing loops sewn to the hammock. That looks pretty strong, but I chose to reinforce the edge and make a channel with a length of amsteel or dynaglide reinforcing it. Then I used a soldering iron to melt through the multiple layers of fabric just inside the reinforcing line so I could attach the shroud lines with larks head knots. When I used very thin spectra 130 lb lines the larks head knots alone would slip, so I backed them up with tiny whoopie slings. However when I used 150 lb or 200 lb dacron kite lines the larger diameter of the lines gave the larks head knots enough friction to hold while I made adjustments. (I later added whoopies for security.) I expect something like paracord would take the larks head knots fairly well, so you might be able to dispense with the guy line tighteners. The stretch of paracord may help some, too. There is a lot of stress on the fabric at the shroud attachment points. I suggest folding it over twice to make a channel, with one thickness extending at least 4" into the hammock bed.
Good luck! Post your results.
That's the current state of it, I have just relied on the strength of the fabric and my sewing to hold on the side attachments, should be strong enough given i am only 8 stone. Going by the massive ridges when I lye down in it it definitely needs to be refined. I think making the lines longer would reduce the ridges?
You could try doubling the number of shroud lines and also lowering the suspension angle (though that will make it less stable). You've probably noticed that the pad is the only thing that keeps it from collapsing. You may want to try guying the head and foot ends out to help out, though that complicates site selection and line complexity. One advantage of those ridges is that you can fine tune them by adjusting tension of the shroud lines. I get better support for my neck, lower back, and knees by tightening up the lines to lift the hammock in those areas.
I separate the shroud lines on each side into two groups and use trekking poles as spreaders to help maintain the length of the bed. This lets me use two different ridgelines, one for the upper body and one for the leg area. It turns out that a shorter ridge line for the legs provides stability without affecting comfort, and a longer ridge line for the upper body reduces shoulder squeeze.
If you try all these things at once, there are so many variables that adjustment becomes very difficult, and it's harder to enter or leave the hammock. If you figure out what size and shape tarp fits the resulting hammock, let me know.
Great project! Please keep us up to date with lots of pics here!
I own & use an Exped Ergo, but have never tried to copy it, though I can sew.
A few thoughts:
As you know, the angle of the hammock body to the line of supports is important. In a gathered end hammock, that angle is zero and the hammock is continually trying to form a long tube, squeezing your shoulders and legs.
It looks like your design is at 90 deg to the line of supports? You will have a difficult time (I think) keeping the hammock from trying to 'get shorter' when loaded. The Exped is more like 45 deg to the support angle, perhaps a bit more.
The number of suspension lines (and darts) is important. The Exped has more than your prototype, I think- something like 10-12 strings per side.
I'd suggest putting a stiffly-inflated pad or a piece of rigid material (stiff insulating foam, or better- plywood) into the pocket to establish the shape you want, and then think about how to engineer the darts, ends and suspension.
For suspension lines, I'd try dyneema - something like this from BearPaw:
Scroll down this page:3/32" (2.5mm) Braided Polyester and Dyneemaź
This 3/32" (2.5mm) braided polyester and dyneemaź is perfect for guylines using LineLocs 3 fittings and/or mini clamcleats (2-5mm). {Does not work with the micro clamcleats (1-3mm).} The cordage is weather and sun resistant and can be tied into knots. The right size to handle easily. Extremely strong for its diameter with a 450 lbs breaking strength and it does not stretch. It is tangle resistant.
http://www.bearpawwd.com/fabrics_misc/fabrics_misc.html
BearPaw shipped to me in Canada with no fuss, so would probably ship to you as well- hopefully at reasonable expense, though you realize that Canda/US postal rates are a lot higher than in the UK (I'm amazed at how cheaply I can get stuff from the UK).
However any non-stretchy cord will do for non-human testing, IMO. Just put a few weights on your 'platform'.
A small scale (1/4?) 'model' might make prototyping more manageable, and mistakes less costly.
I'll try to remember to pull out my hammock and get you some numbers, soon.
PS- 8 stone is 112 lbs???
Just been outside to try it with wider attachment points but it was to windy and it acted just like a kite so I gave up. Hands were frozen to. Inside when hanging higher it was much better, just one easily fixable ridge. I plan to use this mainly indoors so I will not need a tarp for a while.
Yes VictoriaGuy 8 stone is 112oz. very useful comments. Unfortunately i live in the UK and supplies are harder to find and i have to buy from many different websites. The cord I have been using is a combination of para cord, nylon rope and twine (very bad idea)
It snapped... All was ok though due to it being an ergo hammock : ) 50ft of para cord is on its way so soon I will be able to use just para cord.
I have also left a large channel at each end do I might experiment with pvc pipe. I might try that walking pole idea.
Last edited by Logie; 02-08-2014 at 11:50.
I think that it would be better with wider suspension points so might try and get a longer piece of wood to save drilling more holes in the roof.
They get more comfortable when you adjust the cords so the hammock body is turned slightly.
Very sound analysis from VictoriaGuy. I agree on all points except the line choice. Even though I use spectra (i.e. - same as dyneema) myself, I think it's stronger than needed except in very thin lines, which are more difficult to secure and adjust (requires tiny splices). Also a line with some stretch, like dacron (polyester) puts less stress on the fabric at attachment points. Look at dacron kite lines in the 150 to 250 lb. range. They'll be cheaper, too. Or else use paracord, but I think it's susceptible to UV damage.
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