Just another WordPress.com weblog

All looms have limitations.  The most frequent limitation we hear discussed is about the number of shafts a loom has available . . . no matter how many we have, every once in a while all of us seem to want a few more.  But, just as challenging is the possibility for looms to run out of treadles.

For a modest four-shaft loom, there are a total of 14 possible ways to tie-up a treadle as shown in the image below.

Tie-up possibilities for a four-shaft loom

I have yet to see a four-shaft loom with 14 treadles (although, I know of one in LaConner, WA that has 12).  If a treadling sequence for a particular pattern requires more treadles than the loom has, it’s easy to do a direct tie-up.  This means treadle 1 is tied to shaft 1, treadle 2 is tied to shaft 2, and so forth and so on.

Four-shaft direct tie-up

To treadle a direct tie-up, one or more treadles will be stepped on for each weft pick as shown in the following image

2/2 twill treadling on a four-shaft direct tie-up

Another approach that may be possible is to tie-up the treadles as a “skeleton” tie-up.  This is similar to a direct tie-up because weaving may require more than one treadle to be stepped on for a single weft pick . . . however, a skeleton tie-up differs from a direct tie-up since more than one shaft may be tied to a treadle.  Below is the most common skeleton tie-up I use when I weave double weaves on a four-shaft loom.

One way to tie-up and treadle a four-shaft double weave

All of this is manageable on a four shaft loom; however, things get a little more complicated when more than four shafts are involved.  It becomes easier to run out of treadles when one considers that there are over 250 possibilities for tying up a treadle on an eight-shaft loom . . . over 65,000 possibilities for a 16-shaft loom . . . and by the time we move on to 24 shafts, there are nearly 17 million possibilities.  Looms, rooms, and hips are definitely not wide enough.  So, what’s a weaver to do?  Imagine if an eight-shaft loom only had eight treadles . . . How could the following be treadled?

Eight-shaft, 10-treadle sequence

Well, would a direct tie-up be possible?  Probably not for this particular example.  Why?  The direct tie-up treadling sequence for the above 10-treadle sequence shows a weaver would need up to four feet at a given time for some picks.

An impossible direct tie-up treadling sequence for an eight-shaft loom

This is an opportunity for a skeleton tie-up.  There are two challenges when figuring out a skeleton tie-up.  1)  Determining whether a skeleton tie-up is an option, and 2)  If a skeleton tie-up is possible, what it looks like.  This is where my latest “favorite things” comes in handy in helping make the process easier and faster . . . Tim’s Rudimentary Treadle Reducer  http://www.cs.earlham.edu/~timm/treadle/index.php.  This is an on-line tool available to aid weavers in figuring out whether a skeleton tie-up is possible and if so, dissecting the original tie-up into fewer treadles.

First, enter the number of shafts and treadles for the original draft and the number of available treadles on the loom.

Next, enter the tie-up for the original draft.

Within seconds, it will give you one of two results.  It will confirm if a skeleton tie-up is not possible.  If it is, it will provide an alternative skeleton tie-up.

10-treadle tie-up reduce to eight treadles

It will also provide the reduced treadle equivalent for the skeleton tie-up.  In this particular example, each pick will require two treadles to be stepped on for each weft pick.

Unfortunately, not all drafts can be reduced into fewer treadles and woven with a skeleton tie-up.  But, this is one of the reasons dobby mechanisms are so helpful.

In the meantime, I would like to publicly thank Tim McLarnan, Tremewan Professor of Mathematics who developed Tim’s Rudimentary Treadle Reducer  http://www.cs.earlham.edu/~timm/treadle/index.php.  It has saved me a great deal of time and numerous moments of aggravation.

Advertisements

Comments on: "These are a few of my favorite things – #7: Tim’s Rudimentary Treadle Reducer" (4)

  1. I use Tim’s treadle reducer all the time! I love it, too!!! It cuts down on so much extra [not as much fun] work.

  2. Peggy Osterkamp offered a basic tie up on her website (thanks to Jim Aherns) which will handle most 4 shaft possibilities. You will have to treadle between the peddles tho.
    #1 tied to 1, #2 tied to 3, #3 tied to 4 and #4 tied to 2.
    This will allow your feet to ride between the peddles to create most if not all of the combinations possible on a 4 shaft. I have yet to try it, but it does appear to be ‘feet friendly’. I do have 6 treadles on my loom so there’s always something extra in case I can’t reach the combinations. I have seen many 4 shaft drafts on Handweaving.net which require well more than 4 different combinations, sometimes up to 12, so this arrangement seems helpful.

    • loomchick said:

      What you’re describing is a type of direct tie-up. This is extremely helpful to overcome treadle limitations. On a four-shaft loom, there are 14 different ways to tie up a treadle . . . So, it’s easy to run out of treadles.

      I tend to do my direct tie-ups as follows: Tie treadle #1 to shaft #1 Tie treadle #2 to shaft #2 Tie treadle #3 to shaft #3 Tie treadle #4 to shaft #4. Depending on the shafts I need to lift for a particular weft pick, I can step on one, two, or three treadles by using two feet. Sometimes one foot steps on two treadles that are side-by-side.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Tag Cloud

%d bloggers like this: