over fill and it's effect on sizes

[the_gr8t_waldo]

i'm gearing up to build an top quilt . designed to be in the 40-30degree range. thinking that tubes will be down filled 1.2"high and 3.5 wide.. baffels running ina cross the torso direction. the whole quilt will be aprox 10-15% over filled. now as i visualze this, the over fill will "blosson" the tubes and the result will be that the designed length will shorten. being that this is my first attempt at working with down, i'm a bit unsure that the shrinkage is something that must be addressed while in the design stage, if so, what kinda factor should i plug into this project.... or am i over thinking the this?

[HanginLight]

You won't see much difference in length, maybe 2-3 inches would be my guess. The geometry is going from a flat plane to half of an ellipse where the height of the ellipse is only 0.1 extra inch. (maybe 3% difference)

Other thoughts:
- if you want 1.2" with a 1" high baffle, calculate the required amount of down as if the whole quilt was 1.2" high. Then overfill that by 10% or so.
- 3.5" baffle spacing is pretty tight (and its a lot of work too). You can probably get away with 5"-6" or so. Overstuffing will help keep the down from developping voids (cold spots); these are more common when the chambers are stuffed "just enough".

Good luck on the quilt. Lots of good videos on the site to help you...

[JohnSawyer]

Sounds like you're over thinking it, unless you're trying to make an UQ that's an exact fit to your body... an inch too long or too short on a partial quilt probably isn't that critical.

There's a spreadsheet out there that will help you calculate a differential cut... where the fabric against your backside will be taut and smooth, and the lower fabric will contour to a partial-cylindrical shape to maximize loft...

Um... I'll have to find the link... it's here somewhere...

edit: Found it: http://www.hammockforums.net/forum/s...eet+underquilt

[the_gr8t_waldo]

last night i found a spread sheet for top quilts..still, it dosen't seem to even consider this shrinkage. i am a bit afraid of adding an inch here, and another 2-3 "'s there. that kinda approch always seems to end up making something that's only adds weight..and i intend for this to be back pacing gear. still i apprciate your imputs on this

[HanginLight]

Just a thought...
Post your height, weight, quilt dimensions and the hammock / style you'll be using. I think someone here will be able to give you some guidance based on that (not necessarily me, but someone will be close and tell you if they'd feel pinched or not).
I say this because alot depends on details (footbox or not, width, position you sleep in, draft collar or not, what you sleep in / add for cold weather, etc.).