Tuesday, March 19, 2013

3D Orthogonal Draft - less muddy?

I realized my post yesterday was probably pretty unclear, without a draft. Here is my best attempt at a draft:

That does convey more-or-less what I'm doing, in that if you were to thread this up and weave it you should get the same result, but it does not convey well how it actually works on the loom.

In reality, all the purple picks in each of those triangles of purple stack up on top of each other, so I have 7 picks of purple one atop another, as I look down at the fell. Then I change the tabby shed in the black/gray/white threads on 1234. Because they fell is really tall, from all those purple wefts, the black/gray/white threads end up going all the way from top to bottom of this stack of yarns, or vice versa, when I change sheds. A little dot of black or gray or white shows on the top & bottom surfaces, the rest of the thread goes vertically straight down between those surfaces.

What about that weird tie-up?

For a countermarche, this is not a normal tie-up. In order to weave this with one treadle for each weft shot, I would need 14 treadles. But I also want to try weaving twill on shafts 1234, so I wanted to keep some treadles available for that.

Also, in reality I'm weaving shafts 5-10 in order for one "pick", but then 10-5 on the next, so I don't get a big float on the side when the weft goes back to the top.

A skeleton tie-up seemed like a good way to deal with that. With a skeleton tie-up, you can treadle with 2 feet to get more combinations than you have treadles for.

I didn't know if that was possible on a countermarche, so I Googled it, and found a great article by Madelyn Van Der Hoogt on the subject, here is a link to the PDF:


My weaving software doesn't show the bubbles one would normally draw on a countermarche tie-up. If it did, you would see that the 2 treadles for shafts 1-4 are tied up fully, so when 1&3 go down, 2&4 go up, and vice versa. On shafts 5-10, those treadles are tied so that any shaft that isn't going down is going up. So in a sense I've tied up as if I had 2 countermarche looms, one for shafts 1-4, and one for shafts 5-10.

Yes, this means I've effectively avoided doing a proper countermarche tie-up! I'll get to that eventually, I'm sure.

Monday, March 18, 2013

Orthogonal Weaving

A friend loaned me her 12-shaft countermarche loom while she is moving.

My first thought: Lovely!

My second thought: Eek!
I've never tied up a countermarche loom before.

My third thought: Eek!
I couldn't think what to do with 12 shafts. I have up to 8, and I want to make the most of this opportunity.

So, I Googled. First I googled "weaving", and went to Images. There I found several images of handwovens that inspired me. (Who'd have thunk I'd be interested in Crackle? But maybe I'll do that sometime soon.)

Next I Googled "woven", and went to Images. There I found more things that inspired me - but often they were images of things that were not woven. Like quilts, for instance.

But then I found this:
It's the full text of a book about advances in weaving, and about new ways of using weaving in other fields, like architecture.

Then an image in Chapter 5, Multiaxis Three Dimensional (3D) Woven Fabric really got my attention:
The image on the right, a cross-section of a side view of a loom designed to weave the fabric shown in the images above these, was something I could almost understand. My way to achieve better understanding was to set the loom up and weave it.

Here is the result:

This fabric requires 7 weft picks to make 1 "row" of fabric. I was having trouble with the orange/yellow warp yarns not getting caught by the weft, so I used 2 bobbins (one blue, one purple) going in opposite directions in each shed. The orange/yellow warp ends up completely covered.

The black/gray/white warp is actually weaving in the Z-axis. It's doing plain weave, and after 7 shots (between warp layers) in Tabby A, it switches to Tabby B. So it's going up, then down, through the woven structure.

The orange/yellow warp yarns are not weaving around anything. They are straight, and 6 layers deep (threaded on 6 shafts). I'm using the loom to lift each layer so I can put the bobbins through between layers.

The weft yarn is also straight, and not actually weaving around anything (except at the edges when they turn to back through a different shed). The section of toothpick weft conveys that more clearly, I hope.

So, the only yarn that is actually required to be soft and pliable is the black/gray/white yarn. In architecture, this structure could be used with rebar in place of the orange/yellow warp and also in place of the weft, as long as something more pliable (wire?) was used in the Z-axis, the way the black/gray/white warp is here.

Clear as mud?

If there was a way to make all these fibers stick together (i.e. glue, felting, etc.), a loom could weave a solid that then could be machined into shapes. You could weave the 2x4's to build your house with. Except that, even though this fabric is solid, it is pliable. I can twist it. I guess if you wove it with fiberglass and then melted it into a semi-solid blob, it wouldn't flex so much.

So, what's it for? Any ideas? I'm working on a list of thoughts, so far it's things like making a square rope, or decorative ideas. With enough shafts, it would be possible to weave a bag with thick solid sides. Joe suggested a yoga mat, which would probably work well. That made me think of a saddle blanket. I don't think this would be hard-wearing enough for that, though.

If I treat the 6 shafts with orange/yellow as a tripleweave, I could weave a folded fabric like a letter Z, and then stitch the layers together with the black/white, or leave them unstitched so they could unfold. Woven pleats! But if one pleat requires 6 shafts, a fabric with several would be a real shaft hog.

Please share your ideas!