Baffle Direction

[traftonm]

Is one direction better then the other? Side to side or top to bottom.

[Otter1]

Top quilt or under quilt?

[TiredFeet]

Assuming you mean under quilt, then...

I just asked TeeDee and he decided to make the baffles in his Bridge underquilts end to end for 2 reasons:

1. differential cut - if the baffles run side to side, then you have to make the baffles differential cut to avoid down compression due to the top and bottom (inner and outter?) shells being pulled together because of the curve of the hammock. Running the baffles end to end avoids this problem and added complexity.
   
   For a Bridge Hammock this is especially true since the end to end curvature is essentially non-existent for a properly hung Bridge.
   
   For a gathered end hammock, you can only avoid the worst of the problem running the baffles end to end. For a gathered end hammock you still have curvature end to end, but the curvature is still a lot less than the side to side curvature. To fully avoid the problem you would have to make the baffles compensate in both directions. But running end to end would still be the best to avoid compression due to hammock curvature.
2. gravity down compression - this problem is a lot less than the first problem above, but when TeeDee reviewed images of hammocks hung with under quilts suspended beneath, the ones with side to side baffles appeared to show considerably less down at the top of the down chamber as gravity pulled the down towards the bottom of the hammock. Hence gravity induced down compression. Neither he or I think this is a serious problem, but end to end baffles still avoid the problem altogether since the weight of down only acts across the width of the chamber and not the length of the chamber which gives you a smaller column of down to compress the down at the bottom of the column.

No matter which problem is the most serious, running baffles end to end means that you can make the baffles a constant width. You only have to compensate for curvature by making the outer shell bigger than the inner shell.

Running the baffles side to side means that you have to make the baffle width vary along the length of the baffle with the the largest width at the middle and tapering towards each end of the baffle. More complexity to compute in designing and more complexity in the construction.

Also, for a gathered end hammock, running the baffles end to end means you can still make it a double differential cut and compensate for the hammock curvature much easier than side to side. Running end to end, the much reduced curvature means that the variation in the baffle width is much reduced and easier to design, cut and sew. That is if you decide to do a double differentially cut under quilt.

[traftonm]

Thanks Tiredfeet I have to redue my under quilt. First one was 60in long and my feet freeze below 40* and was'ent sure which was best. What you say makes sence..

[Neutron]

1. It looks like if you could do cross baffles easily as shown by boothill in the following link that would solve both problems.

http://www.hammockforums.net/forum/s...ad.php?t=38247

However, he did not sew the cross baffles completely closed in the middle and that could let down shift form one baffle to the other.

Has anyone a method to stuff and sew cross baffles easily? It looks like you would have to take your sewing machine into your "Stuffing Tent" to accomplish true cross baffles. That would require stuffing a center baffle, Sewing it shut and working your way outward a baffle at a time

2. Reading, It appears that stuffing any quilt and sewing it is a mess. I saw water soluble Doggie poop bags on the internet. http://flushpuppies.com/ If you loaded these with the down, threw them into the baffle and then sewed it shut, It looks like this would be a no mess solution . . . or . . . at least less messy then stuffing baffles and trying to sew them shut while loaded with down. Anyone think this would work or see any problems with this method? I do not want to waste the cost of down and screw something up. That way if one did cross baffles, that would solve the mess and you could sew with your sewing machine in a clean environment. Anyway, just trying to think outside of the box.

[Catavarie]

1. It looks like if you could do cross baffles easily as shown by boothill in the following link that would solve both problems.

http://www.hammockforums.net/forum/s...ad.php?t=38247

However, he did not sew the cross baffles completely closed in the middle and that could let down shift form one baffle to the other.

Has anyone a method to stuff and sew cross baffles easily? It looks like you would have to take your sewing machine into your "Stuffing Tent" to accomplish true cross baffles. That would require stuffing a center baffle, Sewing it shut and working your way outward a baffle at a time

2. Reading, It appears that stuffing any quilt and sewing it is a mess. I saw water soluble Doggie poop bags on the internet. http://flushpuppies.com/ If you loaded these with the down, threw them into the baffle and then sewed it shut, It looks like this would be a no mess solution . . . or . . . at least less messy then stuffing baffles and trying to sew them shut while loaded with down. Anyone think this would work or see any problems with this method? I do not want to waste the cost of down and screw something up. That way if one did cross baffles, that would solve the mess and you could sew with your sewing machine in a clean environment. Anyway, just trying to think outside of the box.

What Boothill did is called a Karo Step Quilt. Mostly used for Top Quilts and not under quilts. The advantage to a Karo quilt is that the baffles don't connect, so you can sew the entire quilt up leaving one corner open to stuff through. The Karo stepped baffles help to prevent the down from shifting too much, but don't prevent it completely.

[Neutron]

Thanks Catavarie. It all in a name knowing what to search for.

[Boothill]

in the thread about making the quilts i have a picture of my bottom quilt i made and i just ran the baffles side to side with a sewn through design, the main reason i did this was

1) i really had no idea what i was doing
2) seemed like it would be the easiest
3) i really had no idea what i was doing

but it turned out ok and seems to work good......not really sure if running the baffles the long way would make any difference for the better or the worse in the performance of the quilt, i'm sure i'll make another one some day and find out then

boot