Monday, April 24, 2017

Summer and Winter Weaving Tie-Up

I had sent my Strickler 546 provided tie-up off to Tim's Treadle Reducer, because the tie-up for a dedicated treadle for each pick wanted 14 treadles.  My loom only has 10.

Strickler 546, Summer and Winter weave structure. Getting better.

The tie-up I got back was do-able, but I had to check a cheat sheet for each block, because it wasn't a logical arrangement.

So, I was chatting with Hilary, a fellow student at the Multnomah Art Center, who is ALSO weaving a summer and winter project (summer and winter being the weave structure; we were both working from profile drafts, which are a shorthand way of describing a weaving design).  She didn't have a cheat sheet taped to her loom.

Her tie-up was MUCH more logical, so I went home and changed the tie-up on my loom.  No cheat sheet required.  I can use this tie-up for every summer and winter weaving project I do going forward as well, which is a bonus.  The tie up essentially mimics the profile block tie-up.

We are using 8 shaft looms, so the profile drafts we use can have up to 6 design blocks.

The algorithm (all credit to Hilary) is as follows:

tie
shaft 1 to treadle 1
shaft 2 to treadle 2
tabby b (usually shafts 3-8) to treadle 9

tie the pattern shafts in each block to the corresponding treadle, knowing that multiple blocks are lifted in each treadle.

So, here's treadles 3-8

Profile Treadling Pattern Shaft
F F F F F 8
E 7
D D 6
C C C 5
B B B 4
A A A A 3

where
treadle 3 gets ABCF (shafts 6 and 7)*
treadle 4 gets AB (shafts 5, 6, and 7)
and so on

The draft is treadled in "Pairs X" fashion, and there are 8 picks for each row in the treadle diagram.
Here's a subset of the treadle diagram:

3 4 5 6 7 8
8
3
4
4
4
5
6
6
6
The treadling algorithm is 2-1-1-2, where the 1 and 2 mean that shaft 1 or 2 is to be included in the lift.  Shafts 1 and 2 are lifted together to make Tabby A.  The result is a little "X" in the fabric.

So, substituting the appropriate treadle, to complete treadling the 3,

T+2
1+2
T+1
9
T+1
1+2
T+2
9
where T=3.

Easy peasy.  No cheat sheet.

* you MIGHT think that the tie-up for treadle 3 should be 3, 4, 5, and 8, rather than 6 and 7.  And that's what they call "Tromp as writ".  Which is all good for a SINKING shed loom; the tied shafts go down when the treadle is pressed.  However, for a RISING shed loom (jack looms are rising shed; my loom is a jack loom; it is the most commonly available type of loom used in the USA, I think), one ties up the opposite treadles.

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