Help with hybrid delta baffle design (topquilt)

Can't help you much on the down part of things- only done one regular baffled quilt.

On sizing though-
I'm 5'10" for reference.

What is your footbox? Just a drawcord?
I like the drawcord- because I can open a little to vent- or open more and let my feet hang out. On a chilly night though I found that adding a little 4" diameter "plug was a big help- I always had a little gap when cinched tight.

Point being- with size 12 feet I find I loose about 5" of quilt in the drawcord closure. So factor that into your length if that is part of your design. If sewing in an actual end- then you won't loose any height- but for longer duration use I would suggest the drawcord.

Sides- I like about 30" of sewn together area, after the cord is synched up that gives me about 2' sewn up ( to my knees) so depending on what you want- design your break point for the taper to hit that number IMO. It doesn't have to, just what I tend to do.

Overall length- I would measure from toes to chin standing up, add 5" to that for footbox if needed. Your 80" is probably close. Remember if you belly or side sleep your pointed toes can add 6-8" too.

You mentioned Plush. I take my height plus footbox. It's nice to have a few extra inches of slop for tucking around your shoulders. On a chilly night I curl a little and can then wrap the quilt over my head like a mummy bag. I make my plush stuff around 84" total.

If you want to trim it down but waffle a bit on the lenghth- one compromise is to sew a 6" single layer of shell material to the top to give you something to grab that adds grams.

You can also review some of the specs on Enlightened Equipment and Z-Packs sites to compare your dimensions to their models as a double check.

EDIT-
others may chime in but- I have only recently started using Argon as M50 was unavailable from thru-hiker for a bit. Nothing against the Argon, but M50 has a very solid track record and if you are going for daily use it's probably better safe than sorry. It's only a few bucks more per yard.

Christopher,

There is a Delta top quilt thread here somewhere that addresses some of your questions. It had a lot of great information. In general terms, a delta style baffle system will not have great down control, but your design should help with that. How much? Don't know. Worse case scenario add a couple ounces of down if you find it's not to your liking after a couple trips.

If in doubt and want something different, run a 10/6 KARO.

Ryan

Christopher,

I honestly think the gaps left between the openings will not hold down in place at all, even with 16oz of down.
You basically have 25×18 inch slightly tapered boxes with one strip of material in the middle. That strip wont do much.

I have made a 14-6 karo and the down shift was pretty bad.

I think a 12-7 would work better than a 12-6.
Having unwanted down shift after you spend so much time making something is not fun.

Yeah… poor down control. I went ahead and started putting it together today anyway. I may shorten the side baffles even more before sewing on the inner shell. Maybe add a few more small baffles (2 inches long?) to constrict things in larger spaces. I'll post a few more pictures when I get a chance tomorrow.

I did read the delta step design thread. In fact, that thread is significantly responsible for pushing me toward a more experimental design, rather than the (tried and true) karo step. I'll soon know whether or not to regret it!

Well this is exciting to see :)

Given that a number of commercial quilts have continuous baffles head-to-toe, I wouldn't worry about the lack of horizontal baffles, but over all I agree that the gaps between the baffles look too big.

Mind you, I haven't actually tinkered w/ a baffled design yet. However, when I do, I'll start w/ small mock ups (1.5yd x 1.5yd ?) made from plastic sheet (painters drop cloth) and packing tape. I'll inflate them w/ a hair dryer to get a sense for how much open space there is for a given baffle pattern, then dump in the contents of a 650FP pillow I picked up to get a feel for the down mobility.

I'm about to put in a materials order for a synthetic quilt (my first!) and I similarly mocked up the dimensions in plastic sheet and tried it on to get the size right.

If it's not too late and you have the patience for it, you might consider some plastic mocks before committing all that time and material to an unproven design.

On a related note, I picked up samples of a half dozen different types of mesh from my local fabric store and weighed them all. New rule of thumb says smaller holes and thinner/softer/more supple feel equals lighter. The lightest I found is ~0.3oz/yd (same weight as the lightest Cuben) and they all cost around $5/yd (60"). Any of them would work for karo baffles. This is most definitely what I'll use when I get to that project. Granted, the actual weight savings are absurdly small if you already have no see-um netting (0.7oz/yd) or even just left over shell material.

Good luck w/ the project and keep us posted!

Finished the quilt today sans accessories. In response to forecasts of excess down movement, I sewed the baffles to the inner shell on a curve, decreasing the baffle size at each end. 3" baffles narrowed to ~2" at their ends, 2" baffles decreased to ~1.25". This picture shows a curve-sewn baffle.

Reduced height at the baffle ends restricts down movement between cells at the cost of slight reduction in loft at the baffle ends, which I doubt will translate into noticeable cool spots.

Overall, I think it came out really well. I've tossed it around and stuffed it a bit, and I don't think I'll be having any prolems with down movement. With the extra baffle constriction, + 16oz of 850 in the first place, it's well filled out (over 4 inches of loft, 5+ here and there). Don't have a scale, but it's argon .67 and nano-seeum. Somewhere in the low 20s, I guess.

And already too warm.

Wow, looks awesome! Do you have any pictures of the footbox or of the top of the quilt?

You must be a speed demon at sewing to finish it so quickly!

Top of quiltFootbox
Not a speed demon seamster, just obsessive and underemployed.