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  1. #11
    Senior Member doogie's Avatar
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    Quote Originally Posted by gmcttr View Post
    The following photo of the head end corner of a TQ produced by one of our "cottage" vendors, has the inner shell stretched tight while the outer differential cut shell wraps around the edge allowing full loft.

    Attachment 45986

    Here's a sketch to further illustrate the principle.

    Attachment 45985
    That's not what we are referring to...at least I'm not. That is a given that you need extra fabric for the sides. I actually made true boxed sides to my TQ and posted how i did it. A differential is when the top is wider than the bottom due to it being a larger radius. So if we assume a person has a radius of 12" the minimum bottom layer of fabric would be 24*pi/2 (divide by 2 since we are only covering the top half of the person....about 38" The top layer of fabric for 2" of loft would need to be 28*pi/2...about 44" You would still need to add another 4 inches (2 for each side), but this could be added onto the top or bottom piece of fabric. The tricky part is figuring out how to make the baffles conform. I think these numbers a a little extreme, but hopefully you get the idea.

    Last edited by doogie; 02-06-2013 at 11:31. Reason: added image
    "Mountains should be climbed with as little effort as possible and without desire. ... To live only for some future goal is shallow. It’s the sides of the mountain that sustain life, not the top. Here's where things grow." - Robert M. Pirsig

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  2. #12
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    The illustration that gmcttr shows can be applied to this discussion the only thing that needs to be added is the baffle.

    So take the lower illustration and where the red line ends on each side add a strip of baffle material (however wide need for temp rating).

    The illustration clearly shows the differential cut.
    "yesterday is history, tomorrow is a mystery, but today is a gift---thats why its called a present" - Master Oogway
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  3. #13
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    Quote Originally Posted by doogie View Post
    T...A differential is when the top is wider than the bottom due to it being a larger radius...
    I'm well aware of that and agree that the baffles are not typically cut on a radius and sewn up to create a truly "differential cut/sewn" quilt. However, the extra width of the outer shell does act as a differential cut when you tuck the quilt in under your shoulders/sides and somewhat limits loss of loft.

    Just trying to ensure that the OP doesn't make the mistake of cutting the inner and outer shells the same width.
    Last edited by gmcttr; 02-06-2013 at 11:51.

  4. #14
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    Quote Originally Posted by gmcttr View Post
    Just trying to ensure that the OP doesn't make the mistake of cutting the inner and outer shells the same width.
    No worries.
    The outer shell width = inner shell width + 2* baffle height (also same for length).
    This allows for an "outer wall" and keeps the chambers at full loft.
    When I look at the photograph I see the tucks taking up the corner material created by the "outer wall" allowance (inplace of Doogies corner).

    I am still not clear if additional width (side to side) is needed in the outer shell.

    underquilt.parabolas_19256.jpg

    This pic from Grizz (http://www.hammockforums.net/forum/s...ead.php?t=6466) shows the differential in action - for the longitudinal baffles in an UQ.
    Ignoring the baffles (they would be in the same plane as the paper for TQ), the 2 arcs show the extreme difference in length required of the 2 shells and this is just a partial circle.

    At the foot end of the quilt, when sewn into a closed foot box, a 40" wide inner shell (now=circumference), with 3" loft/height, would need a 58" outer shell circumference. So I can't see how adding an inch or 2 (in addition to the "wall height," would make a significant difference in limiting down compression at such a severe curve (12" diameter foot box).

    I am not disagreeing, just not sure I understand completely. Thank you everybody for the replies.
    Jason

  5. #15
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    Quote Originally Posted by jwright View Post
    ...I am still not clear if additional width (side to side) is needed in the outer shell...
    Technically yes...in reality, I don't know that anyone is doing that. In order to fully take advantage of it, the baffles would have to be cut on a radius as well.

    My experience is, when laying in a hammock with the TQ tucked in at my sides, there is sufficient quilt left to pile on top of me with lots of loft.

    Leave the answer at "yes, but no" and don't worry about it.

  6. #16
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    Ding! Ding!

    We have a winner!
    I agree. I think that the sheer volume of the TQ will make up for any compressed or 0 loft areas at folds/wrinkles.
    Now to cut some m50/NoBul.
    It will be hard to worry about anything encased in all that downy goodness.
    Thanks again to all who took the time to reply. I do think these discussions would take about 1/10th the time if done in person with a beer and pencil/paper.
    Jason

  7. #17
    Senior Member doogie's Avatar
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    Quote Originally Posted by jwright View Post
    Ding! Ding!

    I do think these discussions would take about 1/10th the time if done in person with a beer and pencil/paper.
    Jason
    The actual time discussing the issue would probably be a lot less, but drinking and talking about other things a lot more....more enjoyable too

    Are you going to MAHAA.....I think I'm going to be able to swing it.
    "Mountains should be climbed with as little effort as possible and without desire. ... To live only for some future goal is shallow. It’s the sides of the mountain that sustain life, not the top. Here's where things grow." - Robert M. Pirsig

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  8. #18
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    Agreed.
    I hope to make it. The fall get together was a blast.
    Awaiting the work schedules to come out before I can sign up.

    jason

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