Halloo - I’m a new weaver with insufficient experience to sort out the answers to some problems for a new project I’ve been assigned (my teacher gave me the assignment but has instructed me to ask others for the answers to any problems). So I’m reaching out to you.
A little background: This project is towels, red and white gingham. The original pattern has a red stripe on the left and a white on the right. Each stripe is 24 threads. However, the EPI is 18. Right away my math-averse brain started whimpering.
To add to the fun, teacher has added a red stripe on the right for balance, and provided the additional info that this increases the total epi to 408. I’ve figured out that this requires 102 heddles per shaft for my 4-shaft loom.
The EPI is 18, which is sleyed 2,1 in a 12-dent reed, with a finished width of 17”. Additional instructions for selvedge are to sley either 3 in the last dent, or 2 in the first and last. I understand that with the additional stripe, the EPI and sley order is the same, and the finished width would be 18”. Good so far.
Each shaft is 46” wide, divided in 1/3s by the clips holding the spring steel heddle bars top and bottom. The center section in the shaft is 16” wide. My problem is figuring out how many heddles should be in the center section of the shaft and how many in the left and right 1/3s.
I’ve put 80 heddles in the center section of each shaft and 18 on either side, for a total of 116 per shaft. If there was a reason for picking 80, I don’t recall now.
In my current pattern, if I do the math right, 16” x 18 epi / 4 = 72 so perhaps that would have been a better choice for the middle section, with 15 on each side. Luckily, if that is the better choice, it can be easily remedied before dressing the loom!
There is also information that the threading is 21” wide in the reed. This is 3” more than the finished width is supposed to be (accounting for the additional stripe), so i'm confused there - is this pre-shrinkage? I’ve not encountered this piece of information before - my 1st project was to have a finished width of 7” and we slayed the reed at 7.5”. With this piece of information, factored in, I would probably reduce the number of heddles in the middle section even further, to 48 in the middle and 27 on each side, but that seems really spread out. Showing my work: 1.5” x 18 epi = 27, x 2 = 54, so 102-54=48,
And perhaps none of this matters? I’ve got 116 heddles on each shaft, and I only need 102, so I have more than enough. It’s the centering that has me messed up, and trying to avoid impact from the spring steel clips, which are a pain to move unthreaded and worse once the loom is dressed.
What I do is wind the warp to be slightly wider than the finished width, start threading from the middle, going to the left and then right, and let the heddles wind up werever they want. If you want to to detailed calculations on how many threads are going to be in the middle and end sections, you can do that, based on what the epi in the reed is. Much of your entry is very difficult to understand, and you make a mention of "pre shrinkage" which is a mystery to me. It doesn't matter whether you have an "additional stripe" or not, the width of the piece is the number of threads/epi in the reed.