Insultex Bridge Hammock

[TeeDee]

I've seen this phenomena also (the arc depth being significantly larger than the cut depth). Helps some to pull the hammock ends farther apart. At least when I have, the arc depth is no longer 12" on a cut 6".

Yes - this is where I'm heading currently. Laid in the hammock again yesterday trying to imagine how to compensate for the tension. Adding to the end width would be hard since the final width, no matter what, still has to match the Bridge itself at 44". Thought about trying to add to the length. Same problem, it still has to match the Bridge.

Got up and took the hammock down and changed the ridge line from 114" to 116" and re-hung the Bridge. That helped quite a bit. Then put back to 114". I'm going to change the SLS for a 120" ridge line. That's one of the things I like about the SLS, it's so easy to change and experiment and know just what you are setting it to.

I had already made the suspension triangle pretty small to help compensate and trying to keep the 114" ridge line.

[TeeDee]

Okay - I've had time to test lengthening the ridge line.

It helped somewhat, but not all that much.

Had to pull version 1 apart and essentially start over again. Trying to save what Insultex I have instead of using it up on the design phase, so I had to sew the cut layers of Insultex back together to get whole pieces, then re-cut to the new shape.

I had to make the the outside shell and the Insultex layers much, much wider than the Bridge itself. Also, to solve the problem of the material at the top of the arc pulling the Insultex and outer shell layers up and above the arc in the middle, I had to cut the Insultex and outer shell with a 50% deeper arc than the Bridge itself.

The deeper cut solved the problem of the Insultex and outer shell material being pulled up above the arc in the middle of the arc.

That then lets the greater width of the Insultex and outer shell hang loose and prevent compression.

Of course the greater width and deeper cut created another problem of how to get everything to match up on the perimeter. Darts! Very strategically placed darts with a carefully computed and measured width. Needed some more computer time to compute the needed width of the darts on the arcs.

The extra Insultex and outer shell 1.1 ripstop nylon increased the weight from 25.55 oz to 28.00 oz. I used the full 60" width of the Insultex and the full 64" width of the 1.1 ripstop to get the new extra width. The full width and 50% deeper arc cuts may not be necessary, but I would have to make quite a few Insultex Bridges at intermediate widths and arc depths to find the exact extra measurements needed. That would use up the supply of Insultex I have. I'll just stick with the extra material.

I'm still saving 6.05 oz over the separate Bridge and down under quilt: 12.30 oz and 21.75 oz respectively for a total of 34.05 oz. That's ignoring the 8.75 oz of the Dri Ducks Poncho weather shield I feel I need for protection for the down under quilt.

That's all assuming that the Insultex performs as I hope and expect.

Laying in the Insultex Bridge with my down top quilt really felt great, even in the cold basement. Between the top quilt and the Insultex, it was very nice.

Next I have an Insultex top quilt to design and make. I might make the Insultex top quilt design the same shape as our down top quilts. The size and shape has proven to be very good.

Now, I'm anxiously awaiting cold weather . Maybe I'll just mousy on over and join Dutch

[Mule]

Have you thought of Spandex around the perimeter of the bridge? Mule

[TeeDee]

Have you thought of Spandex around the perimeter of the bridge? Mule

No. But I had thought of shock cord or other expandable material around the edges.

Unfortunately it wouldn't solve the problem. The goal is to keep the Insultex from even touching the underside of the Bridge Hammock fabric proper. In order to accomplish that the Insultex has to be hung loose.

Spandex, shock cord, etc. needs to touch the Bridge in order to stretch.

The experience of people using the i.d.i. gear Arctic Armour and my experience with version 1 is that you want a small air gap. With version 1, the Insultex was tight against the underside. I still had good heat build-up under the torso and legs. But I didn't trust having it tight against the underside. I may have been wrong in that assumption and I may have introduced too great a gap. Have more experimentation to do.

[TeeDee]

Have you thought of Spandex around the perimeter of the bridge? Mule

Mule - Thanks for the suggestion. It cleared my head and got me to thinking - always dangerous.

I needed some means of adjusting the gap between the Insultex and the bottom of the Bridge proper.

After some experimentation, I installed a draw cord channel from end-to-end, threaded some guy line cord down through the channel. I can tie one end to the corner on that end and run the opposite end, the head end, around the corner there. I can lay in the Bridge and pull the draw cord, thus adjusting the air gap. I can pull the Insultex up tight with the draw cord. With the Insultex tight under the Bridge fabric, the heat starts building immediately. In less than a minute, the back feels very warm, almost hot. I can slack off and cool off the back.

The occupant can adjust the desired temperature on the back simply by adjusting the air gap with the draw cord.

Think of it as a thermostat for the under quilt.

When you go to bed, if the temperature is warm enough, just leave the draw cord loose. As it cools off during the night and you wake up, simply pull the draw cord to increase the temperature.

The draw cord is working so well, I'll probably make it a permanent part of the design.