I continue to struggle with how much yarn is needed for a project.  I get the number of ends per inch -  based on the thickness of the yarn, wraped around the 1inch.  If I look at a completed project "Table Runner for Nancy". ( Submitted by Padre Wayne)

Sett:20.00 EPI (ends per inch)  Length on Loom: 72.00 in Width on Loom: 19.00 in InFinished Length: 70.00 in Finished Width: 18.50 in   If the piece is 19 in wide, there are 20 Ends per inch, then I would need (19x20) 380 warp lengths on the loom.  I need to add about 20 inches to tie off the loom (right?)  (72 + 20=92) Then multiply 380 by 92inches; =34,960 inches or 972 yards.  Then I need to have more yarn for the weft.  This is where I get lost.  I have only done a basic even weave so far.  Does the amount of yarn needed change if you are doing a different type of weave?  How do you compute the information when you are given ounces instead of yards?  I am working on a new to me used 4harness Leclerc.  Thanks; Debbie

Comments

Tue, 01/24/2012 - 05:06

laurafry

Figuring weft is a little more challenging than figuring warp, partly because you have to know how many picks per inch you will be weaving.

I use the chart in the back of Shirley Held's book "Weaving".  Basically you need to calculate the number of picks that will be woven (ppi x length woven) and multiply that by the length of a pick, which will be about 10% longer than your warp is wide.  It gets a little confusing sometimes when you have to change inches to yards.

As for ounces, if you know the number of yards per ounce, multply by 16 to get the number of yards per pound.  But you only need to figure out how many ounces you need if you have yards/ounce....

Tue, 01/24/2012 - 05:26

cmaur811

Hello,

I just bought a used Structo Artcraft loom ,4 harness,18 inches wide ,oak.

Could you suggest a beginners book on weaving.

I'm looking to find Mary Meigs Atwater  "Manual of Instructions for Structo Artcraft  to download -I haven't found it yet-any thoughts on where I might locate this.

Thank you

 

Tue, 01/24/2012 - 07:01

laurafry

There are a number of books appropriate for beginners.  For a quick look you can go to the Leclerc Looms website and download Robert Leclerc's book Warp and Weave for free.  

If you want a more in depth look at weaving, Laila Lundell's The Big Book of Weaving covers a lot of ground.  My personal text books were Mary Black's New Key to Weaving, Shirley Held's Weaving and M. P. Davison's green pattern book (title escapes me at the minute).  You don't need a book specifically for the Structo - any good beginning book will let you dress your new loom.  

Welcome to the wonderful world of weaving.  :)

cheers,

Laura

Tue, 01/24/2012 - 07:41

w178 (not verified)

When I started my weaving studies (a long time ago) The head of weaving gave us all a rule of thum that once you have calculated the amount of warp you use the same amount for the weft, and what is left over you add to your stash for sampeling etc.

w178

Tue, 01/24/2012 - 12:04

Michael White

Here on the University of Arizona web site: http://www.cs.arizona.edu/patterns/weaving/index.html

You can find thousands of articles, periodicals, books etc. all in the public domain. This information is on weaving and all aspects of textile.

Michael 

http://www.handweaver.us/georgia_yarn_company.htm

Wed, 01/25/2012 - 00:11

Debbie NC

Ok, Now I am goingto ask a "dumb" question.  when you say "pick"  or PPI are you refering to ends per inch?  is a pick different?  My instructor did not use that term.  I am ok converting inches to yards as I work in a fabric store.

Debbie

PS. I have no idea why this message is typing in bold.

Wed, 01/25/2012 - 00:26

laurafry

A pick is a weft thread, and end is a warp thread.  So you have epi (ends per inch) and ppi (picks per inch).

cheers,

Laura

Wed, 01/25/2012 - 02:16

Debbie NC

I get it.  I woud calculate it the same way I calculate the EPI, wraping 1 inch of a ruler; correct?

I can over estimate,  I do not want to not get enough to finish a project.

Thank you for your help. 

Wed, 01/25/2012 - 02:46

laurafry

How many picks you will have will depend (I know, I know).  For example, it will depend on how many epi you have and the weave structure and whether or not you are using the same yarn for warp and weft.

Based on a 'balanced' cloth (same number of epi/ppi) you use the same number of picks per inch as you have ends per inch.

The 'trick' becomes what happens when you start to do something other than a 'balanced' cloth - and then you will have to weave some samples and record your results so that you know how many ppi you achieve given a particular set of circumstances.

For the time being, go with a 'balanced' cloth, if you are using the same yarn in both warp and weft.

There are times when I will use a much thicker warp and a very fine weft - then I increase the epi, higher than I would if I were using the same grist (thickness) of yarn for weft.

One good exercise for new weavers is to get their hands on actual fabric samples with all the draft info for them, then study what the designer has done and analyse the quality of cloth that results.  And then speculate what would happen if - you changed the thickness of the warp, changed the set (epi), changed the weave structure, changed the colours, changed the weft to something thicker, thinner or of a different texture......

If you have a guild nearby they might have a library with books of sample swatches.  Sometimes you can get sample collections from study groups, or if you belong to the Complex Weavers (or in Canada, the Guild of Canadian Weavers) they have many binders full of samples that can be examined.

cheers,

Laura

Fri, 02/17/2012 - 19:09

Woodburner

I'm having a bit of trouble with this myself atm, and notice that Debbie seems to be making one of the same mistake as I think I was. Could someone please confirm, that for an even balanced tabby weave with the same thickness of thread for warp and weft: you need to divide wpi by two to get epi?

I am sure I have read this in simple plain english somewhere, but can't find it again, only complicated formulae with a lot more variables. :(

 

eta, It's not where I read it before, but it's in Leclerc's pdf, p22. Thank you Laura. :)

Fri, 02/17/2012 - 21:48

sally orgren

OH MY! Yes. We all struggle with this in the beginning!

OK. Here's my take. Dividing your "wraps per inch" by 2 to get your epi is a place to start, assuming you have not jammed the wraps together tightly, and were not winding them on too loosely, either. How do you know? (Well, that was my problem as a newbie, I wasn't sure!)

So I tend to look at sett charts to get an idea of where my sett should be and then compare the ruler wrap to the chart recommendations.

Allowing a bit more warp for sampling at the beginning of your project helps build experience and confidence. Daryl Lancaster always points out that resleying the reed to adjust your sett is one of the easiest things to do after you have set up your loom if the fabric isn't looking right.

Also, as w178 mentioned above, a good rule of thumb for balanced weaves is your warp calculations = your weft. In reality, you should have some weft left over, because you have loom waste accounted for in your warp that won't be present in your weft.

To compute using ounces, you need to know the ypp (yards per pound) of a given yarn. Halcyon among others are very good about providing sett and ypp for their products. 

So here's an example - I am using 16/2 cotton sold on tubes. My warp is 600 threads, (20" in the reed at 30 epi), 8 yards long. Each 8 oz tube of 16/2 holds 3,360 yards. 600 warps x 8 yards = 4,800 yards. So I would need more than 1 tube for the warp. If I am weaving a balanced weave, all the same color, I could get three tubes and have enough for the whole project!

4,800 X 2 (for warp and weft) = 9,600 yards total 

3,360 x 3 tubes = 10,080 yards

Extra credit! If you don't know the yards per pound for a given yarn, that is where having a McMorran Yarn Balance helps. It's just a plexiglass balance. You cut a long piece of yarn, hang it over the arm, and gradually trim the tails until the balance arm is level. Once level, you measure the length of the yarn, multiply by 100, and that equals the yards per pound for that yarn. 

Final tip—Keep good records. That way, the next time you use the same yarn, it will be w-a-y easier. ;-) I'll bet a year from now you'll be sailing through your project calculations!

Sat, 02/18/2012 - 05:43

Cat Brysch

There is a Structo Group here on Weavolution and also there's a yahoo group called all_things_structo.  Also, there's a Weavolution person named Franco Rios (I think is his name) who has Mary Miegs Atwater's "Manual..." There is 3 resources for you...I hope they help!

Sat, 02/18/2012 - 11:25

ReedGuy

Like Mike said there is a wealth of information in those archives. There are some books with drafts and many help calculate warp and weft yardage. There are also guild monographs with tips of all kinds.

Sat, 02/18/2012 - 15:57

francorios (not verified)

Good morning,

Structo manuals can be dowanloaded at the yahoo group

All Things Structo
http://groups.yahoo.com/group/all_things_structo/

You have to register (free of charge) and request to join.
Tell them you have a structo. It may take a day or two.

Then you can download from their files section.
It's a good group to join because it is fairly active with ideas and comments. I have the manuals in PDF downloaded from there that I can send you.

There is also a Structo group on Weavolution

http://weavolution.com/group/structo-central


 

Have a good day!
Franco Rios

Wed, 02/22/2012 - 10:44

ReedGuy

I ordered "The Big Book of Weaving" and "Warp and Weft", both books I thumbed through quickly last night and I am pleased with my purchase. The seond book there goes into weave structures and all kinds of pictures and drafts to try the various weaves. It's a little more advanced I think than beginner, but once you've learn the basics like in the first book I think you'll be a happy weaver. :)

Thu, 02/23/2012 - 01:50

Michael White

Now that very one has used Sally'S figures and knows just how much yarn you need. You will  need to take into account the shrinkage and loom waste. Each type of fiber has a different rate of shrinkage and the weave structure will also effect the shrinkage. Each loom will have a certain amount of warp yarn that you will not be able to use. This is call loom waste.

Thu, 02/23/2012 - 22:17

Claudia Segal (not verified)

There is a weaving calculator in the Resources section of Weavolution that can help you with all the calculations you are struggling with.  It can be found HERE.  Give it a try.

Claudia