DIY Top Quilt questions

[staringcontest]

Hey all. In the process of designing my first TQ and some questions have arisen that I've had trouble finding answers to on here. First off, it's going to be a kero step quilt that I'll be using on the ground 99% of the time. I'm 73" tall. I'm planning on the finished dimensions being 80"L and 56" wide at the head with a full taper to 44" at foot end, using 16oz of 800f down, including 20% overstuff and down used for foot box, with 2.5" baffles. So, my questions are: How long should I cut the fabric to account for the amount of finished length being lost due to loft (not including seam allowances) in order to achieve the 80"? And if I want 2.5 inches of actual loft, should the baffle height be 2.5 as well or shorter? All tips are appreciated.

[CountryRoads]

If your baffles are going vertically, then I think the loss of length will be negligible. Width might be slightly different. 2.5 inches of loft seems like a lot to me. You would need 2.5 inch baffle material if you wanted 2.5 inches of loft throughout 100 percent of the quilt? That is going to be toasty! What temps are you expecting to use it in?

[Scotty Von Porkchop]

How much loft will depend on how big the 'squares' are in the karo pattern as a well filled quilt will balloon out as it goes away from the baffle and the greater the distance between baffles the larger the effect. So a 2" baffle will balloon to greater than 2" but by how much depends on overstuff and karo distance. I usually need a out 3 inches extra for hemming the edges (1.5 each side) but that's because I like extra folds and stitching on lightweight fabrics. You WILL loose length with karo baffles from the ballooning but again it'll depend over fill and distances between the baffles, I remember loosing quite a significant amount on my cold weather karo quilts.

Basically make it way bigger I made mine huge for ground sleeping and love it (stupid big in the hammock though)

Good luck though as karo is king!

[rais'n hammock]

If you want a loft of 2.5" and are going to overstuff then your baffles will be shorter than 2". OR you can use the 2.5" baffles and end up with a higher loft with the overstuffing. If you are limited to the 16Oz of you will need to understand the relationship between the weight and volume of down.

Fill power indicates the volume of a given amount of down. Specifically, it measures how many cubic inches an ounce of down occupies under standard laboratory conditions.
Divide your total volume by the fill power and you will know how many ounces of that fill power down you will need. Add 20% for over stuffing.
Change the variables to know the volume if you start with weight and adjust the thickness of the quilt until you find a happy thickness to hold your 16oz of down.
Area X Thickness = Volume
Volume / Fill Power = Weight
Weight X Fill Power = Volume
Thickness = (Weight X Fill power) / Area

There are calculators out there to help. This one is for UQ but you can get the idea. https://www.hammockforums.net/forum/...=1#post1317305
The TQ Area will be more complicated than the simple rectangle of an UQ and you will need to consider the footbox.

+1 Karo is King. Here is mine... https://www.hammockforums.net/forum/...-Style-Footbox
I love it and it has been good to 30°F so far. I hope to test it down to 20°F this weekend. I had planned for between 5 or 10°F

For the loft allowance, if you want the seam in the middle than add half of the loft height to the cut size +seam allowance. If you want the seam on the bottom at the loft height to the cut size of the outer material +seam allowance.

[CountryRoads]

Oops. Missed the karo baffle part. Listen to Scotty Von Porkchop. I've only made one TQ.

[staringcontest]

It's definitely not going to be a summer quilt, mostly for fall winter and early spring over here in Washington, and some trips to Rainier and Baker I have planned.

[staringcontest]

If you want a loft of 2.5" and are going to overstuff then your baffles will be shorter than 2". OR you can use the 2.5" baffles and end up with a higher loft with the overstuffing. If you are limited to the 16Oz of you will need to understand the relationship between the weight and volume of down.

Fill power indicates the volume of a given amount of down. Specifically, it measures how many cubic inches an ounce of down occupies under standard laboratory conditions.
Divide your total volume by the fill power and you will know how many ounces of that fill power down you will need. Add 20% for over stuffing.
Change the variables to know the volume if you start with weight and adjust the thickness of the quilt until you find a happy thickness to hold your 16oz of down.
Area X Thickness = Volume
Volume / Fill Power = Weight
Weight X Fill Power = Volume
Thickness = (Weight X Fill power) / Area

There are calculators out there to help. This one is for UQ but you can get the idea. https://www.hammockforums.net/forum/...=1#post1317305
The TQ Area will be more complicated than the simple rectangle of an UQ and you will need to consider the footbox.

+1 Karo is King. Here is mine... https://www.hammockforums.net/forum/...-Style-Footbox
I love it and it has been good to 30°F so far. I hope to test it down to 20°F this weekend. I had planned for between 5 or 10°F

For the loft allowance, if you want the seam in the middle than add half of the loft height to the cut size +seam allowance. If you want the seam on the bottom at the loft height to the cut size of the outer material +seam allowance.

That's a gorgeous quilt you have there. That macaw green illume15 looks slick, I actually ordered the same stuff a few days ago. So using your calculations, it puts me at a quilt volume of about 10,000 cu/in, and about 12,800 cu/in of down inside the 10,000 cu/in of quilt (for 16oz of 800f). Some of that 12800 will go into the footbox. However I'm not sure I understand your loft allowance calculation. If i used half of the actual loft height or thickness which comes out to 3.2 inches, I would only be adding about an inch and a half to the cut length +seam allowance? I'm by no means experienced with quilt making but that doesn't seem like it would be a significant enough of additional length.

[rais'n hammock]

That's a gorgeous quilt you have there. That macaw green illume15 looks slick, I actually ordered the same stuff a few days ago. So using your calculations, it puts me at a quilt volume of about 10,000 cu/in, and about 12,800 cu/in of down inside the 10,000 cu/in of quilt (for 16oz of 800f). Some of that 12800 will go into the footbox. However I'm not sure I understand your loft allowance calculation. If i used half of the actual loft height or thickness which comes out to 3.2 inches, I would only be adding about an inch and a half to the cut length +seam allowance? I'm by no means experienced with quilt making but that doesn't seem like it would be a significant enough of additional length.

Thank, it was a lot of fun and very satisfying once done.
Sorry for the confusion on the allowance. You will need to add the same amount to every edge. Meaning, if you have a loft of 2.5" you would add 1.25" +seam allowance to every edge. This will put the seam in the middle. Adding 2.5" +allowance to the outer shell will put the seam on the bottom edge of the quilt.