Am I overthinking this?
I'm planning on making some 20* TQs. I've decided that for these a sewn footbox is a good idea. The things I am trying to figure out are how to do the vertical seam and if any type of differential cut is needed.
So, I'm picturing this is like I did my UQs where the inside layer determines the size and the outside forms around it. With this I'm picturing there being a gap in the insulation by the seam if I sew on the inside. It would seam like it would be neater looking to use the outer edge but that seams like it would make the rest of the quilt hard to work with as it would want to loft in rather than out.
Along these lines I'm wondering if I need to account for the difference in diameters for the inner and outer layers of cloth with a 2" baffle? If I don't do this will I end up loosing some of my loft?
I hope my questions make seance, it's a little after 4 in the morning and I'm over 10 hours into a shift.
Well that kinda makes sense. But I'm right there with you, I'm about to start a TQ of my own and wondering about differential cuts and which way I'm going to do my baffles.
Originally Posted by Mouseskowitz
I was looking at a friends Enlightened Equiptment RevelationX TQ and that has Karo Cuts. It looks like it might hold the down where you want it better but also looks like a lot more work, which i wouldnt mind if im gonna get a better product in the end.
I dont think you will lose loft by not doing a differential cut, (EE TQ did not seem to use a differential cut.) I think you only need a differential cut for UQ because of the way it should fit like a glove on the under side of the hammock.
Your heels are going to compress the down under them anyway, no matter which way the differential is sewn. I put a pocket in the footbox to hold a small ccf pad under my feet.
The heel compression issue is why I made a full length UQ. I guess I'm wondering if I would loose some of the top loft when I make it into a circle. It seems like the patterns I see are more of a flat quilt that is then closed at the bottom. The way I picture it, something will get squished when two pieces of fabric that are the same width are made into a circle.
Your thinking is correct. Without a differential cut the outside fabric will control the diameter and not loft out. However as you touched on, it can still loft inwards which would also reduce the amount of air your body has to heat (a good thing). Just make sure the diameter of the foot box is large enough that your toes don't compress the inner layer against the outer layer.
Originally Posted by Mouseskowitz
I like this idea
Originally Posted by WV
I have made 4 down top quilts and None have a differential cut. The notion that they will not loft properly is Not So...The baffle height will determine how far the shell fabrics move apart..w/o differential both layers will move apart the exact same amount..granted there maybe some loss of loft/baffle height at the very edges of the quilt but overall not enough to worry about. The Excess material from using two different shell fabric dimensions, however, will be of concern during construction as you will have to take up this excess material in the sewing process whether vertical or horizontal...and this can be a real headache. If you were building a mummy style close-fit sleeping bag then the liner shell movement inwards may compromise the loft..In a quilt though which rests on top of you it won''t be an issue.
Last edited by fortran42; 10-28-2013 at 06:01.