View Full Version : minor mod for widening tarp near the top
GrizzlyAdams
08-17-2008, 01:36
One of the challenges of hanging with a bridge hammock is that the spreader bars are wider at their customary height than a gathered end hammock typically is. A normal tarp has to be pitched higher and flatter above a bridge hammock than it is above a gathered end hammock, to avoid having its walls close in on the spreader bars.
A variety of solutions have been bandied about this last year, and I can now offer another, fresh back from field testing.
I bought lightweight tent poles (http://www.questoutfitters.com/tent%20poles-cart.htm) from questoutfitters. 0.344" diameter nanolights. Two sections that make up one 36" pole weigh together 1.15 oz. The pair cost $5.15. I sewed in special tabs on the edge of my JRB 11'x10' tarp, that create a pocket for the pole end. The tabs are 20" on either side of the center pull-out tab. The new tabs both create a pocket for a pole (http://www.hammockforums.net/gallery/showimage.php?i=3919&c=7) end (by a little sewing on the grosgrain) and work as ordinary pull-out tabs as well.
A pole is slipped (http://www.hammockforums.net/gallery/showimage.php?i=3920&c=7) into opposing tabs on one end of the hammock.
Cord is tied to the tie-out loops, looped back and around the tree, and tensioned up on both ends. This creates a sort of ridge, so that the tarp slopes at a more shallow angle up high (and this angle is fixed) and then can slope at a sharper angle to bring the tarp sides down to give better side coverage to the hammock. Here's the result (http://www.hammockforums.net/gallery/showimage.php?i=3921&c=7).
Even with a gathered end hammock this technique will create a bit more head-room. It's a keeper for me.
Grizz
Gailainne
08-17-2008, 04:36
I like that, I was thinking of a similar shape but I was going to use grip-clips, which would need either long poles or trees in the right place, I wonder if the grip clips would allow me to fit a spreader pole on the inside ? that would also allow me to change the shape.
One thing that struck me tho, with the length of the tarp, is sag in the middle, I noticed yours is nicely taut, so perhaps not so much.
Great stuff, next time I'm out for the weekend, I'll have to try it.
Regards
Stephen
Nice Grizz! As usual, of course. Just finished placing order with Quest. That is a lot easier to setup and carry than the quanson hut rig you had at Mt. Rogers. You should submit to The Jacks to include those special tieouts as standard equipment...with proper royalties! :eek::D
FanaticFringer
08-17-2008, 07:36
Great idea Grizz. I'll have to give it a try with mine.:cool:
FanaticFringer
08-17-2008, 08:02
What item number or size grosgrain do you recommend from Quest?
Also, what kind of knot are you using to tie the cords around the tree?
Yep, saw this mod this weekend, and it's a keeper. It widened the tarp just enough so that the hammock spreader bars weren't rubbing on the tarp. Nice work again, Grizz.
Nice Grizz! As usual, of course. Just finished placing order with Quest. That is a lot easier to setup and carry than the quanson hut rig you had at Mt. Rogers. You should submit to The Jacks to include those special tieouts as standard equipment...with proper royalties! :eek::D
I'll bet the Jacks would add the aforementioned "Pole Pockets" for anyone who asked for them. Just point them to this post.
p.s. Grizz, what were we just talking about with the tags. Bad Boy! I added a couple for you.
GrizzlyAdams
08-17-2008, 08:52
Gailainne-I tried the grip clips last winter. They work fine, but you need a really large footprint for the tarp because the lines come off the tarp at a shallow angle. Can be shorter of course if there is cooperating vegetation in the area so you can tie it off rather than stack it in. There is no sag in the tarp middle because there is a lot of tension pulling those spreader bars towards the trees. I belatedly realized that the photos don't capture the line that goes from each corner of the spreader tab, straight back to the tree.
The trees I used this last week were close enough so that the line would go from the tab, straight to the tree, around, back to the opposing tab and through it, then tied off with a taut hitch. I was then able to pull both ends tautly and get the sag out of the middle.
FanaticFringer- I have 1" grosgrain. Item #2032 from Quest.
FishinFinn, on tags. My bad. But hey. Yesterday I was busy for 19 miles on the Brule trying to stay ahead of you, then an 8.5 hour drive home, and THEN the post. I wonder if I used the spell checker.... (thanks for putting the tags there!)
Grizz
schrochem
08-17-2008, 09:25
Wonderful Grizz!
I'm so far behind on the cutting edge of Bridgeology I need to set aside a whole weekend to catch up....
rigidpsycho
08-17-2008, 09:28
nicework as always Grizz.
FanaticFringer
08-17-2008, 09:41
Just ordered my supplies. Under $17 shipped.:cool:
Grizz, really nice. With that huge tarp of mine, the 13 x 14 I need something like that so that the footprint won't be as large. I can bring down the sides under the spreader bars on the tarp nearer to vertical when I want. Thanks for these great ideas. Mule
So the tarp spreader poles are 36" total length.
What are the lengths of your hammock spreader poles? From the picture, it appears to be quite a bit under 36".
My head end spreader pole is 39" and about 41" to 42" tip-to-tip. Seems like I would need more than the 36". My foot end spreader pole is only about 34" tip-to-tip so the 36" tarp spreader pole would give a good margin there.
Also, would it be possible to use spreaders picked up from the ground? Might have to search a bit and use a knife on the ends to shape, but maybe doable also???
Great idea.
One of the challenges of hanging with a bridge hammock is that the spreader bars are wider at their customary height than a gathered end hammock typically is. A normal tarp has to be pitched higher and flatter above a bridge hammock than it is above a gathered end hammock, to avoid having its walls close in on the spreader bars.
A variety of solutions have been bandied about this last year, and I can now offer another, fresh back from field testing.
I bought lightweight tent poles (http://www.questoutfitters.com/tent%20poles-cart.htm) from questoutfitters. 0.344" diameter nanolights. Two sections that make up one 36" pole weigh together 1.15 oz. The pair cost $5.15. I sewed in special tabs on the edge of my JRB 11'x10' tarp, that create a pocket for the pole end. The tabs are 20" on either side of the center pull-out tab. The new tabs both create a pocket for a pole (http://www.hammockforums.net/gallery/showimage.php?i=3919&c=7) end (by a little sewing on the grosgrain) and work as ordinary pull-out tabs as well.
A pole is slipped (http://www.hammockforums.net/gallery/showimage.php?i=3920&c=7) into opposing tabs on one end of the hammock.
Cord is tied to the tie-out loops, looped back and around the tree, and tensioned up on both ends. This creates a sort of ridge, so that the tarp slopes at a more shallow angle up high (and this angle is fixed) and then can slope at a sharper angle to bring the tarp sides down to give better side coverage to the hammock. Here's the result (http://www.hammockforums.net/gallery/showimage.php?i=3921&c=7).
Even with a gathered end hammock this technique will create a bit more head-room. It's a keeper for me.
Grizz
GrizzlyAdams
08-17-2008, 14:00
So the tarp spreader poles are 36" total length.
What are the lengths of your hammock spreader poles? From the picture, it appears to be quite a bit under 36".
Actually no. The spreader bar for the hammock is also 36"---they are the heavier-weight cousin of the spreader bars for the tarp, ordered from the same quest page. There's a nice symmetry there.
My head end spreader pole is 39" and about 41" to 42" tip-to-tip. Seems like I would need more than the 36". My foot end spreader pole is only about 34" tip-to-tip so the 36" tarp spreader pole would give a good margin there.
It is really just a matter of working out the geometry which you no doubt have done already. If the tarp spreader is shorter than the hammock spreader, there will be a limit on how far down you can drop the sides.
Also, would it be possible to use spreaders picked up from the ground? Might have to search a bit and use a knife on the ends to shape, but maybe doable also???
Sure. What I would do though is instead of whittling down tips of trail sticks, I'd lash them to the extra tabs. You don't have to be so exact then about length. And you could be sure to make it as wide as your hammock spreaders.
Grizz
GrizzlyAdams
08-17-2008, 14:04
...I wonder if the grip clips would allow me to fit a spreader pole on the inside ? that would also allow me to change the shape.
I missed this sentence this morning. Dutch has done a mod like this, maybe he will chime in and explain how. When I was fooling around with trying to push out the tarp from the inside with poles this winter, I was very concerned about the tips of the pole pushing into the side of the tarp. So the tips would have to be outside, I can see that it would be worth a try with grip clips to hold them. Let us know what you come up with.
Grizz
headchange4u
08-17-2008, 17:27
Nice mod Grizz. I think I'll perform this mod on my JRB 11x10.
schrochem
08-17-2008, 19:17
I think this would be a good use for hiking poles....
There wouldn't be as much pressure on them as it is for spreaders, so it's just a matter of making pockets for the poles.
FanaticFringer
08-17-2008, 19:24
I think this would be a good use for hiking poles....
There wouldn't be as much pressure on them as it is for spreaders, so it's just a matter of making pockets for the poles.
I've thought about that also. You could make one pocket (grip side of pole) bigger.
FanaticFringer
08-23-2008, 15:18
Finished this mod yeaterday. Took less than 2 hours. Will get pics of it on my next outing. Grizz you da man!!!!!:cool: Because of your killer ideas, I've made a cool DIY bridge hammock, modified my JRB No Sniveller to be used as a double underquilt under my bridge (JRB bridge), and now this tarp mod which should really help with more room with both my bridge hammocks.:cool::):cool:
GrizzlyAdams
08-23-2008, 16:44
Thanks FF. We appreciate your business :D
Grizz
My supplies for this mod should be here next week. It's gonna be a good thing.
BTW, using the heavier version, the 5/8 inch diameter tent poles works great on both the Bear Mountain modified to use 36 inch spreaders and my three DIY bridges. But don't try going much wider. I took an extra pole and added half of it to the 36 inch setup, making the spreader 9 inches wider..... big mistake. I am glad I only did one side. It immediately broke the spreader bars at the insert pin and flung them about thirty feet away. Could have broken window. I think I am going to stay with the 36 inch ones. Mule
GrizzlyAdams
08-23-2008, 21:02
My supplies for this mod should be here next week. It's gonna be a good thing.
BTW, using the heavier version, the 5/8 inch diameter tent poles works great on both the Bear Mountain modified to use 36 inch spreaders and my three DIY bridges. But don't try going much wider. I took an extra pole and added half of it to the 36 inch setup, making the spreader 9 inches wider..... big mistake. I am glad I only did one side. It immediately broke the spreader bars at the insert pin and flung them about thirty feet away. Could have broken window. I think I am going to stay with the 36 inch ones. Mule
Mule, you live out on the edge! You and RamblinRev gonna give the bridge a bad name what with you snapping poles and threatening windows, and him cutting BEEPs and threatening to increase business for chiropractors. :D
My thumbnail sketch, to a first approximation, assuming your suspension sides are the same length as mine, says you increased the compression force on the spreader bars by 50% - 60% .
The "insert pin" is at the very end of the pole where (on mine) you'd stick the pole into a grommet if you were using it on a tent? If so was that pin head the main point of contact with a cap or something (so that more than just force is going on here, there is the increased angle of stress on the pin...) Or do you mean the connector that holds segments of the poles together (which is where I'd expect a snap).
Grizz
Ramblinrev
08-23-2008, 21:05
Now wait... the BEEP ain't just my idea. And it did serve it's purpose.
GrizzlyAdams
08-23-2008, 21:19
Now wait... the BEEP ain't just my idea. And it did serve it's purpose.
Indeed, you'd still be trapped in that bridge without it, till the search party found you...:)
As you discovered experimentally, any cut that is between speader bars is going to want to open up if cut in the direction of the long dimension of the hammock. If you'd done a cut in the short dimension I don't know if you could have gotten your shoulders through, but if you could have, then I think the cut would not open that way, at least not until you hung it in gathered end mode, at which point you'd probably see the end of the hammock tear off. And you sayin' you aren't out on the edge too???? :D:D
Grizz
Mule, you live out on the edge! You and RamblinRev gonna give the bridge a bad name what with you snapping poles and threatening windows, and him cutting BEEPs and threatening to increase business for chiropractors. :D
My thumbnail sketch, to a first approximation, assuming your suspension sides are the same length as mine, says you increased the compression force on the spreader bars by 50% - 60% .
The "insert pin" is at the very end of the pole where (on mine) you'd stick the pole into a grommet if you were using it on a tent? If so was that pin head the main point of contact with a cap or something (so that more than just force is going on here, there is the increased angle of stress on the pin...) Or do you mean the connector that holds segments of the poles together (which is where I'd expect a snap).
Grizz
It broke in the center of the three pole setup and broke on the connector, as you guessed. I am looking for a strengthening insert to put inside the connector to make it a little bit stronger now that I know where the week point is. I still ain't going past 36 inches. It is soooooo comfortable already.
One thing I still have to do is put end caps on my two latest bridges, but the problem is, I really like it without them. I am kicking around in my mind a universal bugnet that would just hang freely over any type of hammock. I was considering too sewing some of that fuzzy fabric, anything that will be gripped by Omni Velcro, on the bottom of the netting so that it would be easy and silent (almost) to get in and out of. I like my zippers in the bug nets I have now, but it would be lighter without all the Omni and zippers. I will run whatever idea I come up with by the Master as soon as it jels. Mule
schrochem
09-14-2008, 10:55
Catching up on cool mods.....
Anyone ever try hiking poles for this?
If the footend has a smaller spreader (say 18"), you might only have to mod one end of the tarp. Would that work or does it throw off the ability to get taut?