Sunday, July 10, 2016

Limits to DRS

I have been spinning about 7 years, and I converted my wheel to differential rotation speed (DRS) about 6 years ago.

As a DRS wheel, my traddy is likely nearing its maximum potential.

# 0 flyer (The Competition)

With its accelerator, it will insert twist at speeds approaching 5,000 rpm.  I do not think there is much room for improvement.  Ball bearings on the drive wheel and accelerator would reduce effort, but are not likely to allow much faster spinning.  While others are modifying e-spinners to DRS, I doubt if they will actually produce yarn any faster.

The other flyer/bobbin assembly is:

#1 flyer
(The Airplane)

With a range of flyer whorls for this flyer/bobbin assembly, I can spin yarns at desired twists between  about 9 tpi and 30 tpi.   For example 9 tpi yields a firm worsted single of  ~ 5,600 ypp and a medium woolen yarn of ~ 4,800 ypp - about the lowest grist yarn that I produce.  And, 26 tpi yields a worsted single at about the spin count ( ~75 meters/ gram) of the Rambouillet  that I get from Anne Harvey.   (The higher twist flyer/bobbin assemblies were set aside when I installed the accelerator.)  Compared to most modern spinners, I like thinner singles, and the yarns constructed from thinner singles, so this system produces the range of singles that I like.  The Competition runs noticeably faster, and is prefered for high twist singles.

On the other runway, The Airplane will produce a hank (560 yd) of 5,600 ypp singles in an hour. While it is actually slower than the #0 flyer, the Airplane is large enough to produce a full continuous hank of 5,600 ypp single, or 1,200 continuous yards of 11,200 ypp singles.  This allows plying 500 yards of 5-ply gansey yarn from continuous singles; and  allows plying  1,000 yard long skeins of  6-ply, 1680 ypp sock or "gansey" yarn from continuous singles.  

The Competition could produce continuous 1,200 yarn lengths of fine singles ( 30,000 ypp and finer, if I  just made another whorl for it. It is not a priory at this time.  

I do not need singles longer than 1120 yards, so I am not going to make the effort to get a larger DRS flyer

 Plying is done on a ST Ashford Jumbo flyer running at ~ 1,600 rpm.  It allows me to easily produce  500 yards of 5-ply sport weight or 250 yard skeins of 10-ply Aran yarn from continuous singles.  That is as close to "ART" yarn as I want to be.

There is a universe of different yarns out there. It is just a matter of  dreaming them, and sitting down in the morning's light to conjure them out of the chaos of a bin of fiber.  Commercial producers are constrained by the cost of twist, and perceived price points in the market.  As dreamers, we can consider durability, warmth,  luster, care, flammability, softness, color, grist, drape, hand, and other issues as we plan the yarns for our fabrics for our objects.  With an accelerator/DRS wheel,  the effort to spin fine singles becomes much less of a consideration.

 For a class of objects such as seaman's sweaters, there are still a galaxy of suitable yarns.  There is nothing sacred about worsted 5-ply.   If it is a voyage to the poles, 6-ply (840 ypp) or even 10-ply (500 ypp) may be better. If you are crossing the equator, then 3-ply (1,680 ypp)  may be better.  If the boat is leaving this week, then MacAusland's Heavy 3-ply is the faster knit. If I had to have such a fast knitting yarn tonight, I would spin it up on the Ashland Jumbo flyer without resorting to DRS.)

Why?  Because with a thick yarn and small bobbins, the change in the effective bobbin circumference and hence the rate of takeup increases so that the inserted twist is reduced below what is required for a yarn competence.  Likewise, plying changes the effective diameter changes rapidly.  Commercial  DRS systems use large bobbins, and  mechanical systems to continuously detect the effective diameter of the bobbin and change the rate of wind-on, so that twist insertion remains constant.  DRS for the hand spinner is much easier with fine singles and big bobbins.

If you really like thick singles, then DRS is not for you.  If you spin fat singles because thin singles seem like too much work, then you should know that DRS may be a path to fine and/ or very fine  singles.

And truly, there are good olives and bad olives.
This olive wood bobbin is perfect for fine singles 
on The Competition. 

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