Sunday, June 01, 2008

Another Way to Calculate Sett

By Leigh

I've just finished winding on my next warp, so I don't know yet how satisfactory the sett I calculated will be. There are other ways to calculate sett. Trapunto pointed out another one in the comments to that post, and I thought it would be helpful to blog about that one too. The formula is....

Sett = WPI x R ÷ I + R

WPI = wraps per inch
R = warp threads in one repeat
I = intersections of weft with warp in one threading repeat

This formula is found in Sharon Alderman's Mastering Weave Structures, which I don't have, but it's also in Interweave Press's The Weaver's Companion (page 36) and in Peggy Osterkamp's Winding a Warp and Using a Paddle, on page 98. The terms vary a bit in each version, but they all do the same thing.

The formula requires a little more information to get started, so I admit I haven't used it more than once, especially since I usually use charts.

Of course my curiosity is up, so I've decided to give it a try. First I need to know a few things.

My threading draft is a four block pattern with 5 warp ends per block, so there are 20 warp threads in one pattern repeat.

From the tie-up, I can see the interactions of warp and weft, and count 4 interactions per block. Multiplying this by the four blocks in the repeat gives me 16. So....

WPI = 65
R = 20
I = 16

Let me plug those in and see what I come up with.

WPI x R = 65 x 20 = 1300
.I + R ..= 20 + 16 = ..36

= a sett of 36

The sett from the other method? 34

I'm officially relieved!

Next I'll thread the heddles and then on to sleying. Hopefully I'll be weaving by Monday.

Posted 1 June 2008 at http://leighsfiberjournal.blogspot.com

Related Post - Calculating Sett

3 comments:

  1. I have just worked out with fear and tripidation my sett for a handspun shawl. I think I will try this formula to double check my results as the epi I have come up with seems ridiculously low.

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  2. I will definitely be interested in what you come up with. Please let me know!

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  3. This is the method that I go by. It is easier for me to picture in my head (literally.)

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