looks great grizz.
I think I'd probably go with 2X4s but if you say it's steady then smallers better.
looks great grizz.
I think I'd probably go with 2X4s but if you say it's steady then smallers better.
Scott
"Man is a stream whose source is hidden." RWE
Originally Posted by stoikurt
thanks, it's good to be done with it. I had a general picture in my mind of how it would go, but as they say, the devil is in the details. Took longer than I expected to get it worked out and put up.
Based on my Boy Scout experiences lashing together weight supporting structures using poles of similar diameter, I was reasonably sure that one frame end could be made as sturdy as needed (provided the weight is applied near places where 2x2's join), using enough cross-bracing. What I didn't know until I built it was how strong the inward force was going to be, and how much wood would be needed to counter-act it.
Having said all that, if this was to be a stand that would be left in the yard without expectation of it being transported, I'd build it around four vertical 2x4's for legs, with two long 2x4's on the ground connecting the triangular braces. But I'm glad for one that doesn't take up much room in the garage when dissembled, and can be lugged to a campsite if needed. It's still a lot of wood to haul around, but at least it is relatively short.
That's a really good suggestion, I'm going to try that.
Grizz
Well I've been busy with other things so I haven't had much time to play.
Here is a pic of my netting
I really don't like the velcro on the end. I just hate the stuff and how it sticks to the netting etc. Does the feel free velcro (or whatever it's called) stick to fabric?
I bought a pair of 0.625" tent poles from Quest
WITH the end tips the one with the insert weighs 76g and the other one 66g. they are 18" long so that makes my spreader bar 36"
Well they didn't bend or buckle out under my load
For that matter I didn't see them flex at all.
BUT as expected there is a lot of force going into the corners.
I sort of messed up and used a grommet that was too small. I had to pull it out and this jeopardized the fabric. I had reinforced the corner with seat belt webbing. As a result the hole got a little 'out of round'
Regardless, I put the proper grommet in and it felt good enough.
I tested it by pushing down and all looked good.
When I started to sit, it busted through one corner.....
So i needed to distribute the force a bit more so I got some washers from lowes.
I'm not sure the washers are necessary if the corner is properly reinforced and using a good grommet. I needed them so I could see if the pole would bend....
So I can tell you that two 18" 0.625" aluminum easton poles will work.
You may recall I tried some .344 nanolights I had on my tarptent and those couldn't make it past the 'push down' test.
1/2" may work...
Carbon fiber or some other light material could bring the weight down because thats 5oz per spreader.
Scott
"Man is a stream whose source is hidden." RWE
So I think we need to work on a good 'field' spreader bar solution.
I'd like to hear how people would make the poles I posted above work.
I think using the corners is ideal and the corner rings can be dropped.
The poles don't have to use the end tips.
I just used them because I thought they would work well with grommets.
A rubber cap could be put on them or some other end.
I went with the .625 because that is what the larger section of my hiking pole is.
There is a possibilty of going with smaller tubing but I wouldn't think too much smaller.
Perhaps a pole section could be 'affixed' to hiking poles somehow or inserted into the pole like TeeDee did with a dowel.
Using pockets or grommets in the corners and a two section lightweight pole is what I've come up with. This site has poles so the foot end could be 18 and a 13 and the head a 26 and 13 (or even 18).
Sorry just thinking out loud.
Scott
"Man is a stream whose source is hidden." RWE
yea pictures!Well I've been busy with other things so I haven't had much time to play.
Here is a pic of my netting
The under-netting piece is suspended by the red line, and if you pull that taut inside, then the under-netting will come up flush against you (so you can put an under-quilt or air pad or warm 'possums in there for insulation?
Free Magic is remarkably good around the netting. A tape side has both loops and hooks. Sometimes the netting will snag a little, but it's not the guaranteed snagging you get with ordinary velcro hook sides.I really don't like the velcro on the end. I just hate the stuff and how it sticks to the netting etc. Does the feel free velcro (or whatever it's called) stick to fabric?
Score! A source for spreader bars that isn't my hiking poles. You're a hero.I bought a pair of 0.625" tent poles from Quest
WITH the end tips the one with the insert weighs 76g and the other one 66g. they are 18" long so that makes my spreader bar 36"
Well they didn't bend or buckle out under my load
For that matter I didn't see them flex at all.
Gotta tell you, IMHO putting grommets in the fabric for spreading is asking for trouble. Get those spreaders attached to the rope that you're suspending from, or webbing with your next version. The fabric isn't designed to take that force, and putting the spreaders there causes the spreading force to sort of dissipate in the fabric, rather than carry back along the body of the hammock. I once had a conversation with TeeDee about this by PM and that was his opinion as well. But I bet you can figure a way to hang washers or something from the ropes that will let you use your new poles without threatening the fabric. Just my $0.05 worth.BUT as expected there is a lot of force going into the corners.
I sort of messed up and used a grommet that was too small. I had to pull it out and this jeopardized the fabric. I had reinforced the corner with seat belt webbing. As a result the hole got a little 'out of round'
Regardless, I put the proper grommet in and it felt good enough.
I tested it by pushing down and all looked good.
When I started to sit, it busted through one corner.....
So i needed to distribute the force a bit more so I got some washers from lowes.
I'm not sure the washers are necessary if the corner is properly reinforced and using a good grommet. I needed them so I could see if the pole would bend....
So I can tell you that two 18" 0.625" aluminum easton poles will work.
You may recall I tried some .344 nanolights I had on my tarptent and those couldn't make it past the 'push down' test.
1/2" may work...
Carbon fiber or some other light material could bring the weight down because thats 5oz per spreader.
I cut the body of v0.2 this afternoon. It's going to be the vehicle for playing around with the lowered spreader bar idea. But summer fun is over, and work is back with a vengeance. I expect I'll only be able to poke at this hammock stuff off and on now...
Grizz
That's correct...for a future version. This is a bugnet 'adapted' for this so it's not all that snug. Notice I don't have a zipper. I can just tuck the top in between the net bottom and the hammock.
I need to get a hold of that stuff.
I just looked at my hiking poles and saw the stiffness of the upper part. I still think there is a better/lighter option out there. I might go find those CF push rods headchange posted and get some in .625 or .5
Well I can see that for sure. I was hoping reinforcing the corners with seat belt webbing would be sufficient. I think it will be fine if done right, but I would like to do it right on the next version. I'm not sure if I'd like a 1/4" hole for the grommet going through 1/2" webbing....
Also, I was thinking moving the spreader down there would 'help' according to your analysis of moving it lower. Isn't it the same thing, but you just want to go lower?
I got all the stuff, just need to make the template and do some cutting. Testing the spreaders was something I wanted to try before doing that. Now I might have to play with that a bit before settling on a design.I cut the body of v0.2 this afternoon. It's going to be the vehicle for playing around with the lowered spreader bar idea. But summer fun is over, and work is back with a vengeance. I expect I'll only be able to poke at this hammock stuff off and on now...
Grizz
Scott
"Man is a stream whose source is hidden." RWE
you can get it here. Sold by the 25 yard roll. Enough to last a while (unless you use it the way I did for v0.1)
OK, I believe that with enough re-enforcement the fabric may take the strain. Seems still not to "focus" the spreading in the direction you want, but maybe that's my imagination.Well I can see that for sure. I was hoping reinforcing the corners with seat belt webbing would be sufficient. I think it will be fine if done right, but I would like to do it right on the next version. I'm not sure if I'd like a 1/4" hole for the grommet going through 1/2" webbing....
Also, I was thinking moving the spreader down there would 'help' according to your analysis of moving it lower. Isn't it the same thing, but you just want to go lower?
I'm not thinking of poking a hole in the webbing for the spreader. What I'm trying to do is find a way of using my poles as spreaders, which is going to mean lashing them to loops in something. Angrysparrow pointed out the icicle hitch, which grips smooth surfaces, so that's the pole end of the lashing. Now I can imagine 1/2" webbing running the length of the interior of the hammock, in a horizontal line that just passes under the lowest point of the suspension line, looped at both ends for the poles. Two remaining issues : (1) how to attach the extra webbing (ideally I'd like it to be removeable. It could be sewn, but then I'd be really committed!), and (2) will it work?
Adding webbing will increase the hammock's weight, but that has to be viewed as freeing me from carrying single use spreader bars, for an overall weight reduction.
I have a lot of the 1/2" webbing still, perhaps I can answer the "Will it work" question by sewing it into v0.0.
no kidding. Measure twice and cut once.I got all the stuff, just need to make the template and do some cutting. Testing the spreaders was something I wanted to try before doing that. Now I might have to play with that a bit before settling on a design.
Grizz
hey guys, what are the problems associated with using reg. hiking poles?
i remember the strength issue, but it seems like a regular tent pole section placed inside the hp would be enough reinforcement. seems like teedee said (who knows for sure now) that the dowel would keep the poles from compressing shorter, which makes sense.
What am i not thinking of?
hey, just had a thought, if the pole is moved down, the force on the spot where the bed fabric attaches to the spot where the spreader is attached, will not get distributed over the whole length of the arcs.
i think the spreaders would be strongest (less damaging to fabric) in the corners, and moving it down will disperse the forces to a much smaller area of stitches.
if the spreaders are left in the corners, the force is distributed to the whole cat cut side. i'm not saying it can't be lowered, i just think the same stress will be on a much smaller area.
if i understand you right grizz you are talking about having webbing running flat(not curved) under the cat cuts and across the "gap" on the ends making a rectangle at lowered spreader hight that encircles the user?
if that is right, i don't think sewing it on would hurt anything, as unlike a regular horizontal seam would do, it is one soild piece running through the seam, which would take the perpendicular load instead of being transferred to the stitching like on a regular a seam. the only thing would be the needle holes, i think they would be fine, after all fabric already has thousands of holes.
i don't know if running the webbing like this would do that much though, as force from bodyweight to the spreader attachment points would be comming up from below.
i think the best bet is to just mirror the main suspension arcs with lower ones for the spreaders. i mean if you're going to add all that webbing anyway. it's the same concept as why the main ones are an arc instead of a horizontal line to begin with. just distributes the load evenly along the arc rather than overloading the corners.
i suggest making prototypes out of 1.1 if possible, as weak points and possible fabric damage are much more easier to spot, as with heavier fabric there may be no visible immediate damage, but failure over time. constant high stress would be easier to spot with 1.1. the stitch holes will severely stretch with just a couple uses if there is too much stress in a small area, which i think, is the main concern of lowered spreaders, but who knows, maybe this wouldn't cause much more point stress than if high bars are used, but i have a feeling the force on the fabric at the pole attachment point will be enough to cause eventual failure, and it would be arcs that would distribute it evenly, although a lowered arc would likely go into the laying area of the hammock
Last edited by warbonnetguy; 08-26-2007 at 13:28.
TeeDee did a mod on his poles so that he has nice center nubby metal bits at both ends, like Scott's hiking poles. This puts the force straight down the center, which is where you want it.
The forces on that pole can be considerable, as most of us who have these things have seen spreaders bend or split can attest.
My personal objective is to find a way so that a stock pole can safely take off-centered forces. If I lash a pole to the webbing, then the forces won't be directly down the center, and will try to bend the pole because the force isn't exactly aligned with the axis of resistence.
Or maybe I can hack my poles a little to be a wedge between webbing or ropes, and then the strain is on the handle, and who knows how strong that will be. I don't think I can crack the cover on the pole to put re-enforcement inside.
Far as I know, none of us have snapped a pole yet, so maybe this all is just my conservative engineer's paranoia (obviously not shared by a guy who has climbed into a hammock suspended from a small sized figure-9 !!!
Grizz
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