Karo step underquilt plans and question

**htom_servo** · 01-31-2017, 20:33

OK so i'm moving on to my newest project, the all important underquilt. i really like the look of the karo step quilts so that's what i'm going for. ive got me some fabric on the way and just wanted to put my basic plan past all of you much smarter people too see what i'm missing.

basically i'm looking to build this https://youtu.be/lhVgUGx0xAM
utilizing this basic walkthrough

so for my dimensions im looking at a final quilt 60 inches long by 45 inches wide with 1.5 inch baffles. the boxes will be 9x10 with and extra 1/2 inch to all sides for the outer shell. my main question is what lof should i be looking for to get a 30F quilt? reading around it looks like 2-2.5 inches of loft should do it. imputing the numbers into the underquilt calculator and the karo step calculator i looks like i will need just under 7oz of 800 fill down, does that sound right, and will that get me where i want to be on a karo step design? any input is welcome

also a quick thank you to everyone whose info, and resources i'm using here. i think id be lost without all the shared wisdom.

**Trail Troll** · 01-31-2017, 21:04

There be plenty more folks smarter then i bUT I got about that for 2 inches of loft, for 2.5 it was around 8.5 oz, no over stuff. I hadn't done one yet but Tacblades has some pretty nice karo quilts too. I'd like to try one my self soon.

**Rain Man** · 02-01-2017, 10:52

I've made two DIY modified KARO UQs. Don't recall where I read it on here, but I adopted the rule of thumb of 2" baffles for 20 degree and 3" baffles for 0 degrees. Of course, the center of the KARO squares will "poof" out more than the baffles.

**Just Bill** · 02-01-2017, 11:30

http://www.zpacks.com/quilts/down_loft.shtml

The Z-packs chart- (via Backpacking Light) has become a reliable source for MYOG use.
30% overstuff is the generally agreed upon number when calculating fill as well.

**Trail Troll** · 02-01-2017, 12:37

Thanks Just Bill, I couldn't remember where I'd seen that chart before, so I couldn't find it.

**PharmGeek** · 02-01-2017, 13:56

please let me know how it goes....I have decided that I have no good reasons particularly why I chose traditional baffle designs for my TQ and now pending UQ being built, but suspect all work if built well enough.

I plan to make my kids a couple kid sized down TQ's and may try my hand at karo step later on.

I may make another TQ for myself later on as karo step just so I can play with both in real time and see for myself.

Best of luck!

**Just Bill** · 02-01-2017, 14:28

The karo is a good pattern for UQ's IMO. Gravity is on your side and you won't be thrashing around much.

For a TQ... not so much.

**htom_servo** · 02-01-2017, 17:10

Originally Posted by Just Bill

http://www.zpacks.com/quilts/down_loft.shtml

The Z-packs chart- (via Backpacking Light) has become a reliable source for MYOG use.
30% overstuff is the generally agreed upon number when calculating fill as well.

Some great info. Thanks for the link.

Ill try to keep posted on my progress, and will definitely post the final product and all relevant info.

**Trail Troll** · 02-01-2017, 22:31

Originally Posted by Just Bill

For a TQ... not so much.

Any reason why? I ask cause I was thinking of making me a set soon (I hope).

**captainhaddock** · 02-02-2017, 06:10

Hey there,

I thought the common overstuff for a TQ was 20% and about 10% for an UQ?
Isn't the overstuff mainly to compensate for the missed volume during calculation?

The formula to calculate amount of down is pretty easy for a Karo step, if I'm not mistaken: (L*W*BH*OS)/FP.
L = Length in inches
W = Width in inches
BH = Baffle Height in inches
OS = overstuff; for 20% => 1,2
FP = the fill power in CUIN/OZ.

In your case:
(60*45*1.5*1.2)/800 = 6.075 oz

This will get you the approximate amount of down required to fill the area of your quilt. It gets a bit more complicated if you have tapers etc as you need to calculate for the removed area.

Hope this helps!