Tuesday, May 05, 2015

Numbers

Once again, somebody complains about all the "unhelpful" numbers that I spew out.  I do admit that I like numbers.

Actually, the numbers would help, if she knew how to use them.  I do not use unhelpful numbers. However, I sometimes allow people who do not know how to use a number to see it.

The fastest way I know how to spin is double drive - without slip.  That means differential rotation speed (DRS) between the bobbin and flyer. DRS doubles or triples the speed of my spinning wheel. It is the difference between spinning 150 or 200 yards per hour and spinning a full hank of 560 yards all skeined per hour.   The math is in Alden Amos's Big Blue Book.  It is pages and pages, so I am not going to repeat it here.

To make the bobbin and flyer whorls, I must do the math.   A few minutes of math and wood turning to save hours and hours of spinning.

To do the math, I need to plan the kind of yarn, its grist, and calculate the twist.  See Alden Amos BBB pg 383.  I calculate DRS and make the whorls.  Grist. Twist. Yarn Construction (woolen/ worsted).  Give me 2 of the 3,  and I can tell you the third. The Bradford spin count system and DRS makes spinning specific yarns easy.  DRS defines the twist.  Each twist defines the grist of two yarns -- one worsted and one woolen.

Once I have the whorls, I can spin fine and fast for a long, long time. The whorls will last for millions of yards of singles.   A few hours of math and wood turning, and in a month I can spin what would take others 3 months to spin.  Of course, if you are the fastest spinner at the fair, it will take you 3 only 3 months and the others will take much longer.  It is a matter that DRS can control drafting at higher speeds than you can.

Now, you show me a pile of fleece, and tell me that you want as much yarn as possible spun from it.

I take out my "twisty stick" estimate the spin count, and given the weight of the fleece, I can easily calculate how much yarn can be spun from the pile (spinning at the spin count), and how long it will take.  Every contract spinner needed to be able to make these calculations.  Likewise, every factor needed to be able to make these calculations.  It was by getting such calculations correct that the Medici family made their fortune.

Or, if you want a particular grist of yarn, I can tell you if that grist can be reasonably spun from that wool, and if it can, how long it will take. Or, I take my twisty stick to the fair, and estimate how much effort it will be to spin THAT sack into THE yarn that I want.  Or, I can order 56 count long wool and know how it will spin. The Bradford system tells me what I need to know.

In spinning, time is money. The Bradford Spin Count system was the conversion factor for:
 pounds of wool <=> yards of yarn,
from which twist and time could be easily calculated.
It worked for many hundreds of years.  It still works.

I spent 50 years in the metric system. I loved it.  I still love it, but for spinning, the Bradford Spin Count System is easier.  It was developed and refined by generations of professionals.  For spinning wool, it is more helpful than metric.

I do not waste my time with unhelpful numbers.


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