Saturday, September 13, 2014

Twist and grist

I said, that for a hand spinner, inserted twist defines grist. A test is reported below showing that hand spinners can control grist to plus or minus 5%.  Can you control grist better?

This summer I have been spinning "10s" - worsted 5,600 ypp singles.

I wound a dozen hanks of 560 yards and weighed them.  Each should weigh ~45.4 grams.

I used a particular set of flyer bobbin whorls, spun 7 or 8 grams of single, then wound it off onto a storage bobbin. Then, I wound the storage bobbin on to a skeiner, blocked the hank with steam, and weighed it.

Mostly the hanks weighed right in the range of 43 to 48 grams.  Thus, by using DRS to control twist, it is possible for hand spinners to control grist to within plus or minus 5% over samples of 560 yards and maintain a specific grist over projects of many hanks.

Smaller samples tell me that this can be done with 20s or 40s.  I did samples of finer singles in the middle of the above test.  It is possible to spin 10s, then spin much finer 20s and 40s, and then go to back to spinning 10s at the same grist as before.

The 8 lb of  5s loom warp that I did last year with the smaller and less precise whorls, runs about plus or minus 12%.  (At the time, I thought the yarn was reasonably consistent for hand spun, and was very happy to have hanks anywhere in the range of 80 to 100 grams.)

By planning twist, one can control grist.  This is deep inside the world of  "the intentional spinner." The only path here, that I know, is DRS.  Without DRS I do not think you are going to be able to control grist to within 5%.  Without DRS, it is going to take you much, much longer to spin 7,000 yard of 5,600 ypp,  2,240 yd of 11,400 ypp and 1,120 yd of 22,400 ypp singles. Really, how many tries would it take you to spin a 560 yd hank of single that weighs between 10.5 and 12.5 grams? With DRS, I can be reasonably confident of spinning such a 40s on the first try.

It was not always like that.  Better tools brought better skills.  Better skills let me design and make better tools, and so forth.

Today, I find the omission of DRS by Judith Mackenzie to be grievous.  When my variation on grist  with DRS was 12%, and SG told me she could maintain grist within 10%,  I could give a pass to intuitive spinners who did not discuss DRS.  However, now that I know more of the control that DRS can provide, then failure to discuss DRS is a serious error and omission.  Alden Amos at least brings the topic up and discusses the math, even if he does not get into the details of hand movements and mechanics.

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