Ongoing DIY: Complete Hammock System

[Pipsissewa]

A question on this for those of you out there with more sewing experience than I: how hard is it to sew a stretchy spandex or lycra material while its stretched out to its maximum?

That's how you sew elastic to fabric to make a gather. It's not hard at all. Just stretch the elastic out and hold it tight as you run it and the fabric through the sewing machine. When you let go, voila! the elastic shortens up and the fabric gathers. Stretchy spandex or lycra should work the same. Good thread. I'm enjoying reading about your DIY analysis. Thanks, brother!

[FLRider]

Problems with setting up in the rain aside, I think the poncho/tarp ideas is good. A slight modification I would suggest is to offset the head hole towards the front (so the front is shorter) to keep from stepping on it, and to give more length for covering your pack.
Hope that makes sense.

PF

It most definitely does. I've been tied into the ol' GI poncho dimensions (since that's what I carry right now), but your idea has merit. Perhaps altering the back end to the tie-up point for the sides instead of the collar?

I think the front, assuming that I gather it in the manner I intend, should be the right length to cover me without tripping me (I find that the GI one fits near-perfect for me). The back, though, could probably use a little more coverage...hrm, I guess I'll have to take a few measurements with my current poncho and my pack on.

That's how you sew elastic to fabric to make a gather. It's not hard at all. Just stretch the elastic out and hold it tight as you run it and the fabric through the sewing machine. When you let go, voila! the elastic shortens up and the fabric gathers. Stretchy spandex or lycra should work the same. Good thread. I'm enjoying reading about your DIY analysis. Thanks, brother!

Thank you. It all may wind up being a lot of sound and thunder, signifying nothing...but it's worth thinking over, even if it winds up not working. Stay tuned, I'll post updates as soon as I get my sewing machine working again...

[FLRider]

So, I've gotten into and past the basic design phase to actual Alpha testing. I had several priorities when I started this project; they've changed somewhat due to experiences that I've had on the trail. Weight has become a much more important factor for me since my Foothills Trail trip, mostly due to bitter experience with an heavy pack on that one.

So, with that in mind, I've gone over to some more conventional design aspects in places and some...less so.

Let's start with the hammock:

It's a standard 11 ft by 5 ft blank to start.

I roll-hemmed the long edges and then roll hemmed the short edges to make a channel for a Warbonnet-style whipping (I used braided mason's line here; it's lightweight and cheap, and the whipping does not depend on the strength of that cord).

Then, I sewed the loop portion of hook-and-loop (Velcro) to the hammock body along the long edges, over the hems. I started from each end of the hammock with 24" of 0.75" wide loop. Once that was sewed in place, I sewed an 80" long piece of 1.5" wide loop in between the 0.75" wide stuff, along the hems once again. This provides a secure anchor for my under insulation and allows me to use the bug net with my undercover/poncho (more on that later).

I then added 1/8" Amsteel loops, using a triple fisherman's knot to hold them together. I then larksheaded those to a pair of descender rings on each end and larksheaded the whole mess to the hammock whipping knobs. I sewed loops in the ends of 15-ft lengths of 1" polyester webbing (five bartacks, spaced 3/4" apart) and am using those as the suspension system for it.

Before attaching the head-end Amsteel to the hammock, I sewed up a BlackBishop Bag for the hammock and under insulation (my top insulation goes in another bag, but I find it convenient to have the bottom insulation ready to go). I then ran the head-end Amsteel through the button hole and larksheaded it to the hammock.

I then added the CRL. I did not use an exact measurement for this; instead, I hung the hammock in my front yard and lied down in it several times, adjusting the suspension length in between tests, to ensure the proper length. Once the hammock was at the proper length, I cut a piece of 1/8" Amsteel and triple half-hitched it to each whipping knob.

I then cut and sewed the bug net. I used DIY Gear Supply's dimensions for the zippered bug net that they give on their how-to page. Instead of using a zipper, however, I sewed 0.75" hook (the other half of the Velcro) to the netting at the edge. The only difference I made in dimensions was to leave 5" at each end instead of tapering to a point the way the directions show; here, I sewed 2.5" of hook and 2/5" of loop to the netting, to allow it to close over the Amsteel loops at the ends of the hammock.

After some field testing, I added shock loops (1/4" non-roll elastic, 4" long) to the netting, approximately six inches up from the long edge and 30" from the head end, to accommodate a stick as a spreader bar in order to keep the netting off of my face.

Next, I made the tarp. Again, DIY Gear supply came to my rescue. I used their ultralight asymmetrical tarp, since I was trying to save as much weight as possible. The only modification I made to it was to use LineLoc 3s on the guyline tie-outs, to allow me to adjust the tarp without leaving its coverage.

Finally, I made a poncho/undercover/Garlington Insulator. Here, I took a piece of 1.4 Sil, 60" wide before hemming, and cut it to a length of 90". I hemmed the long sides. Next, I hemmed the bottom, leaving a channel for 1/8" shock cord. I ran the shock cord, tying a stopper knot at one end and putting the other through a mini cord lock. I then cut a 10" wide slit for an head hole and cut a 12" long slit for a front vent. I added OmniTape (the non-stick Velcro) for 30" from the bottom hems up the long sides for a closure and suspension system. I then roll hemmed around the head slit to make a channel for a collar drawstring (this was actually the hardest part). I then added Omnitape to the 12" vertical slit that I'd cut and added a piece of 0.5" grosgrain at the bottom to keep it from expanding downward on the front of the poncho.

The poncho is also an undercover for the hammock; I pull apart the side closure OmniTape and then press that to the bottom side of the 1.5" loop on the hammock body. The shock cord on the short ends of the poncho get pulled tight to provide end closure against wind intrusion, and the bug net gets pressed against the top side of the loop to close that (thus allowing for mosquito protection even in pouring, gusty rain).

I tested that last night and this morning during the fringes of Tropical Storm Isaac, and I'm happy to report that it worked well. Without the undercover, the wind-blown rain would have soaked the hammock body on the windward side. With it, I didn't notice any wind-caused water intrusion at all; it all beaded up on the outside of the sil undercover and ran off. However, I did notice that I was getting water intrusion through the head-end Amsteel loop; the descender rings were outside the tarp's coverage and weren't acting as a drip stopper. Easy enough to fix, though. I just need to shorten the loops.

Drawings, photos, video, and weights will come later this week or next week. However, I'm happy with my progress so far, and field testing has brought some minor tweaks to my attention. The spreader bar was one of them; shorter Amsteel loops (to keep the descender rings under the tarp's coverage) are going to be another.

It's held up well in heat, humidity, voracious mosquitoes, pouring rain, and high winds so far. I'm hoping for some cooler weather some time soon to test the under insulation...

[FLRider]

The inner of my modular underquilt design is a two-layer, full-length IX. I just tested this last night: it was a little less impressive than I'd hoped, but not terribly far off of my temperature expectations. It appears to be good to about 45* F with normal clothing for those temperatures.

Specs:

Length: 78"
Finished Width: 52", tapering to 25" at either end.
Raw Inner Layer Width: 52"
Inner Layer Darts: 4 x 6.75" W x 20.25" L per end
Raw Outer Layer Width: 56"
Outer Layer Darts: 4 x 7.75" W x 23.25" L per end
Attachment Method: 1.5" wide, full-length Velcro
Weight: 10.25 oz (this will increase when I add the next layer's suspension Velcro, probably by about 2-3 oz; will make a note of it when I do).
Temperature Rating: 45* F.