baffling questions about baffles

[hipockets]

I am planning to making a down underquilt. Why do the baffles perpendicular to the lenght of the hammock and not parallel to the lenght? Seem like the radius would be less if the baffles ran long ways. The baffles would deform less and hold a more consistent distance between the inside and out side of the quilt. Does cutting the baffles on a radius help? Could I put a 1/4 inch dart on the inside edge every 5 or 6 inches and create a radius with straight baffles?

[te-wa]

i touch on this subject on my blog. youre on the right track...
(sig link)

[Coffee]

I made 2 quilts with horizontal baffles. I notice the down settles a lot. I think whenever I need to make another one, I will make box baffles like TeeDee posted somewhere. I think that could be the best of both worlds.

I did a lot of thinking about how to make true sealed box baffles. I have a montbell bag I love that has that. I couldn't come up with any that would be worth the extra work.

[Dutch]

I've made both. If you want a poncho quilt I think it is best for perpendicular baffles. However all my quilts these days are with differential baffles and that makes more sense to have them run with the length. I also have narrowed the baffles to 4" which helps keep the down in place. Makes for a lot of sewing though. I don't think yo uneed a radius on the baffle b/c it is loose fill and should conform. although I think the snugfit uses it but that thing is a peice of art.

[TeeDee]

After much consultation on the forums and thought about the effects of side-to-side or end-to-end baffles I decided on end-to-end for really 2 reasons:

1. gravity induced compression. With side-to-side baffle on an under quilt, gravity can compress the down towards the bottom of the hammock, since gravity is operating the full half-width of the hammock. Think of it as a column of down. With a width of, say, 48" for the under quilt you have column of down 24" high for the gravity to act on. The down can start compressing towards the bottom of the hammock. Down is light, but gravity is relentless.
   
   With end-to-end baffles the gravity has only the width of the chamber to act. If the chambers are 4" to 6" wide, there is not enough of a column of down for gravity to induce any noticeable or appreciable compression.
2. baffle design. With side-to-side baffles and a differential cut on covers, the baffles have to either be cut with an arc or be sewn with pinch pleats to the inside/top cover. With end-to-end baffles the difference in arc between the top and bottom covers makes a differential cut on the covers much, much easier and hence the baffles cat be cut as straight lengths with a few or no pinch pleats. Makes the job of construction much easier.

So with those points in mind I decided on end-to-end baffles. For a Bridge Hammock the end-to-end curvature is non-existent and so I didn't have to design any arc into the baffles at all. Much, much easier construction.

[mmmm Scotch]

And now I want a te-wa!

[animalcontrol]

I understand the effects of gravity on a UQ and the benefits using side-to-side or end-to-end baffles.
But, does it matter as much on a TQ? Most major manufacturer of sleeping bags that I see use side-to-side baffles. (It seems that end-to-end would be easier with less # of baffles)

[animalcontrol]

bump (I'm really curious on baffle differences on top quilts)

[TeeDee]

bump (I'm really curious on baffle differences on top quilts)

I doubt it unless it was also doing possible double duty as a bottom quilt occasionally.

If it was purely a top quilt, myself I would calculate which way would yield the shortest total baffle length (assuming there was a difference - not obvious to me off the top of my head) and then use that option.

Another consideration: the end-to-end baffles would yield fewer chambers to fill and hence reduce the work involved.

What can I say, I'm basically lazy.

[warbonnetguy]

with side to side baffles on a tq, you could shift down from the edges to get more over your torso. don't know how practical that would be since tq's are somewhat minimal width to begin with. i wonder why nobody has made a sleeping bag with the baffles running head-toe?