Planning Stage

[XTrekker]

Been doing a little research here and there and some planning for my Full Length 0°F UnderQuilt. Whipped up a quick sketch of the Outer-Shell for the UQ. My expected finished length will be 72" x 48".

Anyways, wanted to get some feedback. I will draw up the Inner-Shell later but wanted to know if I was forgetting or miscalculated anything. Any improvements?

[Mountnman]

I hope we get to see a video of your project.

[Boston]

I'm planning an UQ right and so this is relevant to my interests.

Here are my observations:
1) You are SOOO an engineer...nice drafting though ;-) I like to use excel to sketch this stuff lol.

2) Are your "darts" true dart's (sewn down the length) or just pleats? If shaping the quilt you'll probably want to sew a true dart.

3) Are you doing a differential cut? Looks like it based on baffle size and pleats (6" chamber width on the inner shell?). You need to add you're baffle height to the outer shell width on each side - which will impact your overall baffle size, and will probably affect your quilt width due to fabric width limitation.

4) Consider a differential cut in the L dimension too. Use a pleat to take up the slack.

5) Are you sure 72" is enough length? Most commercial quilts are around 78". Depends on your height, obviously.

6) I'd recommend using CatSplat's underquilt calculator. I copied it to a new sheet (because it's protected) and added seam allowance and dual differential to the fabric size calculations.

[VictoriaGuy]

Interesting project! I've built a sleeping bag (never again!) but never UQ...
I'll follow your progress on this - lots of drawings & pictures, please!

A few questions:
-Does anybody take measurements from the ('loaded') hammock to see what width (and taper) of UQ is needed? I'd have thought a 'barrel' shape would result...or is the rectangle to accommodate diagonal sleeping in an end-hung hammock?

-A lot of the UQ pics I see, show a setup with a big 'air pocket' between the UQ and the hammock body. Doesn't this 'free air' reduce the efficiency of the UQ?

-Your 60" - is that the fabric width, and is the 2" your outside hem & channel allowance? I understand that 60-12(8x1.5 darts)=48.

-It looks like the plan is to make the inner layer 48" (no darts) ?

[aka.jobbe]

The cuts you are making in each end. Did you remember seem Spice on Them.

[XTrekker]

I'm planning an UQ right and so this is relevant to my interests.

Here are my observations:
1) You are SOOO an engineer...nice drafting though ;-) I like to use excel to sketch this stuff lol.

Thanks. I'm in school for it right now. MechaTronics (Automation)

2) Are your "darts" true dart's (sewn down the length) or just pleats? If shaping the quilt you'll probably want to sew a true dart.

I was going to do darts but I dont want to sew down the length of the dart so I guess the correct term would be pleat. I think the pleat will allow the chamber to expand unrestricted closer to the hem vs a dart that will constrict the chamber size for several inches away from the hem.

3) Are you doing a differential cut? Looks like it based on baffle size and pleats (6" chamber width on the inner shell?). You need to add you're baffle height to the outer shell width on each side - which will impact your overall baffle size, and will probably affect your quilt width due to fabric width limitation.

Yes, it will be a differential cut. And yes 6" chamber width. I didnt think of adding the baffle height to the outer shell width but I will be sure to add it in now. I honestly didn't think it would affect it that much but it won't hurt to add it so might as well. I'm guessing i can just add 1.5" to each side.

4) Consider a differential cut in the L dimension too. Use a pleat to take up the slack.

Need alittle more elaboration here. Do you mean a pleat midways down the Length of the UQ? I was considering that but opted against it for simplicity vs effectiveness.

5) Are you sure 72" is enough length? Most commercial quilts are around 78". Depends on your height, obviously.

I have gone back and forth on the length for several months and to be honest I am still not set on the length yet so I may consider a longer quilt length. I am 6'1"

6) I'd recommend using CatSplat's underquilt calculator. I copied it to a new sheet (because it's protected) and added seam allowance and dual differential to the fabric size calculations.

Wouldn't mind seeing your modified copy... And thanks so much for your informative response. I would rather expose the design flaws now than during the review of the finished product. I am always open to any recomendations.

[XTrekker]

Interesting project! I've built a sleeping bag (never again!) but never UQ...
I'll follow your progress on this - lots of drawings & pictures, please!

A few questions:
-Does anybody take measurements from the ('loaded') hammock to see what width (and taper) of UQ is needed? I'd have thought a 'barrel' shape would result...or is the rectangle to accommodate diagonal sleeping in an end-hung hammock?

-A lot of the UQ pics I see, show a setup with a big 'air pocket' between the UQ and the hammock body. Doesn't this 'free air' reduce the efficiency of the UQ?

-Your 60" - is that the fabric width, and is the 2" your outside hem & channel allowance? I understand that 60-12(8x1.5 darts)=48.

-It looks like the plan is to make the inner layer 48" (no darts) ?

Yes, 2" for channel and hem.. But that number may change. This is just the first design draft. After a lengthy discussion here I will redraw the design with final modifications added.

Yes inner layer is 48" no darts. Just dont see the need for darts (or actually pleats in this case) on the inner layer.

[XTrekker]

The cuts you are making in each end. Did you remember seem Spice on Them.

I am assuming Spice means space.lol
Yes, but if 2" seems alittle low then I may increase it a bit. I can always use a hemmer foot to get a rolled hem of 0.25" and then fold over 1.5" for the channel and still be within my 2" allowance.

[Boston]

I was going to do darts but I dont want to sew down the length of the dart so I guess the correct term would be pleat. I think the pleat will allow the chamber to expand unrestricted closer to the hem vs a dart that will constrict the chamber size for several inches away from the hem.

Are you planning to try and shape the quilt, or just doing a rectangle? Dart's will shape the quilt to the bottom of the hammock, a pleat is a dart with zero length, basically, and can still allow air gaps. The dart will narrow the chamber, but if done correctly I don't see it affecting loft.

Yes, it will be a differential cut. And yes 6" chamber width. I didnt think of adding the baffle height to the outer shell width but I will be sure to add it in now. I honestly didn't think it would affect it that much but it won't hurt to add it so might as well. I'm guessing i can just add 1.5" to each side.

This is a critical part of a differential design, to prevent the fabric from compressing the down when the quilt is snugged up to the bottom of the hammock.

Need alittle more elaboration here. Do you mean a pleat midways down the Length of the UQ? I was considering that but opted against it for simplicity vs effectiveness.

Basically the same thing as above. You add extra length to the quilt to create a "Box". (If planning 8 6"x2" baffles with a 1" differential and liner is 72" x 48" + seam allowance than shell is 76" x 60"+ seam allowance {72"+2*2" x 8*7"+2*2"} ) It's not as critical but is easy to do. The pleats are to take up the extra material so your edges align. I'd do 1 at each end (4 total for L direction)

I have gone back and forth on the length for several months and to be honest I am still not set on the length yet so I may consider a longer quilt length. I am 6'1"

I'd def go longer if I were you.

Wouldn't mind seeing your modified copy... And thanks so much for your informative response. I would rather expose the design flaws now than during the review of the finished product. I am always open to any recomendations.

Attached. I also added the Jardine formula for loft vs temp rating to the Temperature Estimate section as a reference. My modified sheet isn't protected, so you can screw with the formula's if you want, just be careful. The original is still protected.



Also, one more thing: I realized I had to reduce my width to fit in a 58" fabric width (using Argon). To accomodate this I plan to do a 1/4" rolled hem on the long edge, and add channels after if needed. I'm going to prototype my liner to shape the quilt with darts so I'm hoping I don't need the side channels.

[XTrekker]

Are you planning to try and shape the quilt, or just doing a rectangle? Dart's will shape the quilt to the bottom of the hammock, a pleat is a dart with zero length, basically, and can still allow air gaps.

Air gaps. I was just going to fold the fabric and stitch over it down the ends of the UQ. I guess I could go with Darts but I just wanted to allow the UQ to puff out as much as possible and darts seemed to constrict the chamber until it tapers off.

This is a critical part of a differential design, to prevent the fabric from compressing the down when the quilt is snugged up to the bottom of the hammock.

Gotcha, ill add it in..My baffles will be either 2.5" or 3" so i'm guessing I should add 1.25" or 1.5" to each side of outer-shell dimensions.

Basically the same thing as above. You add extra length to the quilt to create a "Box". (If planning 8 6"x2" baffles with a 1" differential and liner is 72" x 48" + seam allowance than shell is 76" x 60"+ seam allowance {72"+2*2" x 8*7"+2*2"} ) It's not as critical but is easy to do. The pleats are to take up the extra material so your edges align. I'd do 1 at each end (4 total for L direction)

I think I get it but I am worried I may be picturing it wrong.

I'd def go longer if I were you.

Might as well..

Attached. I also added the Jardine formula for loft vs temp rating to the Temperature Estimate section as a reference. My modified sheet isn't protected, so you can screw with the formula's if you want, just be careful. The original is still protected.



Also, one more thing: I realized I had to reduce my width to fit in a 58" fabric width (using Argon). To accomodate this I plan to do a 1/4" rolled hem on the long edge, and add channels after if needed. I'm going to prototype my liner to shape the quilt with darts so I'm hoping I don't need the side channels.