that UQ is nothing short of AWESOME!!!Originally Posted by theclark5
that UQ is nothing short of AWESOME!!!
Last edited by JmBoh; 10-10-2016 at 10:52.
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Surprised I've missed this thread. That's exceptional looking. Very nicely designed!
Nice work fella!
To answer the other question too-
60GSM (grams per sq. meter) or basically 2 ounce- 3" OC quilting in both directions is needed. (Patagonia Nano-Puff is an excellent example)
100GSM (3 ounce/yd) you can reduce quilting to 6" OC across the width of the roll. (one direction only)
120GSM- same deal.
Though as discussed- those are Primaloft's official recommendations. Climbashield requires 24" OC quilting when using APEX- something every vendor I am aware of violates. I think once we know more about PLG generally- it may be safe to encourage pushing those specs in much the same way. Especially in the relatively low stress application of an UQ. TQ's see much more tugging and twisting and caution is warranted there.
After that- to be blunt- much like Climbashield there is little to no benefit from continuing with synthetics unless cost is your only consideration. The weight advantages of synthetics fall off around 40* and down becomes the better choice from a weight, compression and performance standpoint. For some reason I can't quite quantify- field experience and conventional wisdom tells us that (unlike down) piling on synthetics is not a lineal progression of greater warmth and as you pass roughly 20* the intended ratings and field reports don't bear out properly.
On paper- PLG should be roughly 45* rating with 100GSM material. (technically 43.1*) On paper- every ounce past that adds 5* of warmth. (4.9* officially) though I think it's realistic to downgrade the finished piece 5*-10* for an UQ application. So one layer of 6 ounce should have put you around 30*- a second layer of it closer to zero. Though construction technique has some bearing especially as with these thicker layers you are losing more average loft to quiting. But point being- unless you compressed the two layers by supplementing; two layers of 6 ounce should have done much more for you than it did. But again- that's part of the problem with synthetics generally- the paperwork doesn't match up with the field reports and something in the model is broken at lower temps that escapes my carpenter brain as I didn't study enough of that stuff in depth to quantify it. So bottom line- understanding what PLG is good for and not good for is key to using it well. It's a very exciting insulation for all of us- but it does have some limitations that need to be addressed when selecting it. I do suspect that quilting the 6 oz (versus two layers of 3 oz) was a factor as well for this build. I think with Apex- you aren't subject as much to sewn through (quilting) losses- but then you are stuck with other limitations (bulk, feel, stiffness, slower to warm, breakdown with use, etc).
That said- there is a good argument to be made for doing a 45* (roughly 3oz PLG or 3.6oz Apex) synthetic as an OUTTER layer in a stacked UQ system. I think that a good 20* down UQ is a nice piece to own. A good synthetic 45* can serve well as a summer piece (40* and up) as well as second layer for winter use (20* down plus a 45* synthetic gets you to about zero) and most importantly this puts your synthetic layer in the portion of your sleep system where moisture (body vapor) is likely to hit a point in the system where it can freeze or get trapped. The synthetic layer is less prone to loss of performance overall. In addition- because the shell is a DWR and typically calendared fabric- it can serve as a windshell/mist cover and if you happen to nick the shell on some brush, catch a spark, or have a "breakfast from the hammock" incident you won't puke geese all over the woods with the synthetic exposed. This lets you use .67 ounce shells (like Membrane 10) with little fear of durability or damage since repairs are easier and not catastrophic.
I think it sounds like you are coming to some of these conclusions as well as we all learn more about some of these higher end combos of products and what does and doesn't work in Underquilts specifically. I have found that PLG has it's place- but synthetics don't do very well in volume unless you're really going overboard with them. I would say that 3/4 oz PLG is the premium product but beyond that in an UQ application there is not much benefit versus other insulations. In a top quilt- a double layer of 3 ounce is very effective to about 25*- but that performance doesn't transfer to an UQ application as well and in the smaller footprint of an UQ (especially a bridge) down is not dramatically more expensive for the DIY or even regular consumer. However at 45*, PLG can be lighter, cheaper, and better performing than down. Especially in the warmer, moisture laden parts of the year when you are out for more than a few nights.
I do have a pound of the PLG down combo (750 fill equivalent) that I plan to play with this winter in the form of an UQ experiment I have planned (virtually no baffles).
Anywho- Great job on this build overall! Don't mean to hijack things- but exciting to see more folks explore this stuff and to continue the discussion.
Both versions look great and congrats on following through and getting it done.
Fantastic craftsmanship right there!
Thank you all for the compliments. Kyle thanks for the continued innovation and design. I'm having a hard time enjoying one build because you keep coming up with better fabrics. I really encourage everyone to give the DIY a try. For me, after making lots of gathered end hammocks of different fabrics and widths and integrated quilts... I believe I have found my favorite hang with the bridge design. I like the integration and glad I pulled the trigger on the down. I have been holding off because I didn't want the hastle of stuffing down. I got over this and honestly really not that bad. Just realize you will get some flying feathers. I need to work on the design of the end caps as I'd like them to hang down a bit more. Again thanks goes to Grizz for his design and video. It's getting cold here in Central Oregon and hope to get out next weekend to give a field report. I would agree with Just Bill in that primaloft is a great synthetic but down I believe will surpass when it gets into the 30's.
Hi all !
This is my first post in this forum ...
I just wanted to thank you for the excellent instructional PDF posted. I just made my first DIY hammock based on it.
(Currently it's still somewhat work-in-progress : No end caps, gear pockets or pouches nor insulation yet ...)
The optimal spreader bar length is still a bit mystery for me. I started with 92cm, but it causes slight elevation just under the bars.
This elevation or bump could actually be beneficial as it feels like I wouldn't need any pillow at all ..
Or maybe it is just matter of finding the right tension on suspension ?
My solution for the spreader bar attachment points is perhaps a little different than described elsewhere.
I also did not stitch the channel right next to the fabric edge and near the cord but a bit further away because I thought it would be stronger there.
Also the channel portion extending beyond the bars is not currently attached to the cord at all. Seems to be fine so far ...
IMG_20161013_150950.jpg
From the famous ABoK I found a nifty way to attach three spliced loops together.
IMG_20161013_151051.jpg
Tree strap ends and the knot used to attach suspension line is my own devising.
The cord used is Southern Ropes Super-12 UHMwPE. I think it's probably very similar to Amsteel ..
(The attachment point area edges has been folded to the middle of the strap and stitched over. Then a loop is formed and the flat portion is stitched together.)
IMG_20161013_151641.jpg
I did consider UCR type of adjustment, but it seemed to add weight and complexity in addition to some limitations in the minimum distance.
Welcome!
That three loop combo is interesting, thanks for sharing.
I am also keeping my first stitch a bit further than Grizz (about a 3/4" away). Doubt it helps the strength but it makes it easier to get three even rows in (which is where the strength comes from).
There is typically a bit of rise under the bar in my hammocks but it's not quite as hard as you're describing... that could be the fabric but I suspect it's your choice of channel construction.
I would definitely put the part of the channel extending beyond the bars into the cord- it may relieve some of the tension at the bar itself as well.
Otherwise I personally find that the 45" fabric to 36" (92cm) bar is perfect so I'd lean more towards your other choices in construction as the culprit. If you have bars you can trim easily... I have found that shortening the bar does cause more drop/softness at that location but it may cause other issues for you like too much sag in the middle- though increasing the tension (a more level hang) overall can help pop the center up again.
that looks really good. I like the contrasting color blue/gold
Thanks !
I also considered splicing those three cords together (or even having one big loop and then splicing one cord at the mid point).That three loop combo is interesting, thanks for sharing.
But the I just happened to find this and it seemed the most straightforward and flexible. Now it's easy to disassemble if there happens to be a big trunk or two suitable smaller ones so that no spreader bar is needed. (Similar way as was advertised for MadTree Tarseer ..)
I read a lot of comments about dyneema cord slipping with knots. This might be true for many established conventional knots. However I was able to easily figure out by myself a knot which seems to hold well, is relatively easy to tie and then untie after loading. So far I haven't found this particular knot in any books .. However it seems so obvious that probably it has been used before somewhere.
I would appreciate any comment and any further proposals for hardwareless knotted approaches (excluding UCRs and whoopies as they consume quite a bit extra cord).
I have seen some similar fabrics tearing and fibers separating when stitching is too close to the edge. Of course the melted edge from hot knife help a lot .. but still. Then I added a fourth row of stitching just to be sure.I am also keeping my first stitch a bit further than Grizz (about a 3/4" away). Doubt it helps the strength but it makes it easier to get three even rows in (which is where the strength comes from).
I wouldn't say it's any way hard or extreme. Just something I noticed when quickly trying out. (And I do prefer quite flat pillows ...)There is typically a bit of rise under the bar in my hammocks but it's not quite as hard as you're describing... that could be the fabric but I suspect it's your choice of channel construction.
I don't think the channel end construction makes much difference. There seems to be potential stress point when the cord exits the channel. So I decided to cut the channel and double it at the exit point by folding over. The gap area is covered with a smaller folded over piece. (I doubt any opened portion of the channel really supports the fabric underneath.)
End channels are currently freely sliding on the cord to minimize any extra stress. Those seems to remain pretty flat and not crumble up.I would definitely put the part of the channel extending beyond the bars into the cord- it may relieve some of the tension at the bar itself as well.
But let's see over the time how things settle down ...
This is good information. I was quite uncertain if thing were way off. I didn't find any definite answer what was the design length for spreader bars. However it seems my reverse-engineered guess was spot on. As I lack any experience on bridge hammocks (and sewing, materials etc. fabrication) it's still pretty much trial and error style experimentation. I'll try things over the time as everything is still adjustable. There is no dedicated spreader bars yet, but adjustable hiking poles instead. (Maybe even self-adjusting if not tightened enough.)Otherwise I personally find that the 45" fabric to 36" (92cm) bar is perfect so I'd lean more towards your other choices in construction as the culprit. If you have bars you can trim easily... I have found that shortening the bar does cause more drop/softness at that location but it may cause other issues for you like too much sag in the middle- though increasing the tension (a more level hang) overall can help pop the center up again.
Is somewhere more information about different possible spreader bar materials ?
Aluminum electrical conduit piping and old composite skiing poles came in my mind ...
(Yes, I know there are fancy carbon-carbon composite and beryllium alloy pipes, but the budget is kept minimal by principle)
Welcome to the forums... I really like your spreader bar attachment solution. Going to incorporate that into my next build. I use a soft shackle to connect each leg together. I'm weaning myself off the Dutchware crack and I find that using the soft shackles allows me the freedom you describe. Great ideas all... thanks for Sharing!
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