Thursday, June 16, 2016

Comprehensive revision

I have Lyme Disease.  It crept up on me, starting circa 2005, and I did not realize how very disabled I was.

It dramatically affected my strength, endurance, vision, balance, and coordination.

Thus, circa 2011, as I set out to discover just how fast a professional hand spinner could spin in the era 1550 to 1750, I was significantly disabled.

 Now! after more than a year of intensive antibiotic treatment, I am better.   I am not well yet, but I am better. Today, I have more strength, endurance, and coordination than I had in 2011 and a great deal more than I had in say 2014.  Thus, today I do spin spin faster. Therefore, all of the timed spinning in previous posts is conservative.

One could expect a healthy, professional hand spinner with moderately good equipment to spin faster.

My current considered judgment is:

  •  That a DRS controlled flyer/bobbin assembly with an accelerator wheel operated by a professional hand spinner should be able to produce 560 yards of worsted spun 5,600 ypp commercial grade warp yarn (10s) per hour, even if the spinner has substantial health issues.  Woolen spun yarns of about the same twist ( 9 TPI) can be spun faster. 
  • That a a DRS controlled flyer/bobbin assembly with an accelerator wheel operated by a competent hand spinner can spin woolen or worsted yarns with ~ 20 wool staples in cross-section at a good commercial pace. Romney is easy to spin at more than 20,000 yards per pound, Shetland can be spun at more than 30,000 ypp, and  fine wools such as Merino or Rambouillet can be spun at more than 40,000 ypp.  Fine worsted singles can be reasonably spun at rates of more than 3 yards per minute. Thus, 20,000 ypp 2-ply worsted yarn can be prepared at an over-all rate of 60 yards per minute.
  •  20,000 ypp 2-ply is finer than any American entry in the last longest thread competition.  A reasonable time budget to spin, and ply, 10 grams of 20,000 ypp 2-ply using  a DRS controlled flyer/bobbin assembly with an accelerator wheel is on the close order of  25 hours.
  • Wool yarns of less than 20 fibers are either fragile or require excessive twist resulting in a unpleasant yarn. I stopped producing wool singles finer than ~ 50,000 ypp.  My goal is to spin better yarns, not finer yarns.
I thought that I needed to make a new spinning bobbin for the Aldan Amos #0 flyer that I was using for fine singles. Along the way, I was going to photograph and describe the DRS spinning bobbin production process. With my revived coordination, I find that a new bobbin is not necessary, so I am just going to post pictures of the spinning bobbins that currently fit the AA flyers.

The AA #0 flyer/bobbin as delivered :
 Single on bobbin is the test single spun by SG.

  AA bobbin detail (ends bored out, brass flange bearings inserted, wood rings glued in to cover brass bearings)

Detail of AA whorl

Flyer with the (2d generation) DRS bobbin/whorl by me:
Bobbin and whorl of  tropical hardwood with Delrin bearings (thanks to Henry Clemes).  The wood was a scrap picked up inexpensively at a Rockler promotion.

Flyer/bobbin disassembled

Ends of bobbin bored out to receive bearings

AA #1 Flyer bobbin with 3d generation - DRS bobbin and whorls

These 11 whorl diameters provide ability to spin woolen and worsted singles from ~3,000 ypp to more than 45,000 ypp. Note the difference between whorl diameters is small.

Bearings for this flyer/bobbin assembly are replacement bearings for skate boards.  Bearing wise, this is over kill as differential rotation is only ~50 rpm.  However, the center of the bearing fits AA's flyer shaft, and this saves me some effort. The skate board bearings are much better than what my local hardware store sells, and much cheaper than what the local bearing specialist charges.

Detail of borings to receive bearings

Detail of bobbin shaft inserted into board cut bobbin end/whorl

All in all, not particularly pretty, but wickedly effective. The oak in the #1 bobbin is recycled from our kitchen remodel. Since then, I have moved to turning ALL whorls from maple to get a more even texture around the whorl, and avoid belt dressing build up at the cross grain.

Storage bobbins to fit 0.25" spindle:

 Front,  Right to Left; board cut redwood ends on redwood barrel, 2x redwood turned from solid blank, blank
Back, Right to Left;  reels for blocking singles, 2x board cut maple ends/whorl on maple barrel, blank for maple barrel. 

Turning tools:

For 5,600 ypp singles, and 50 mm whorls, required accuracy of whorl diameter is about 0.5 mm.
For 40,000 ypp singles, required accuracy of whorl diameter is higher.  Thus, turn a little larger than needed and sand down to final required diameter.  (If your tools are really sharp, no sanding is required for appearance.)

Use HSS tools and keep them very sharp.  A good procedure is to grind to shape, and then hone.  For honing, I use 400 grit emery belts on the Sorby Pro, or a diamond hone.  Do not try to burnish HSS turning tools.

My OLD Bedan  is carbon steel, and it can be BURNISHED and is sometimes used to clean up where the ends meet the barrel. (But was not used on the current generation of spinning bobbins  : )

Burnished tool steel is sharp, but does not hold an edge 
as well as honed HSS.  

If you use a good hone, and get the angles correct, then HSS is as sharp as the very best burnished tool steel edge, but a HSS edge lasts 10 times longer.  Finishing whorls, I figure the edge on my HSS tools lasts 10 minutes, thus a burnished tool steel edge lasts for ~ one cut.  Turning redwood bobbins from solid blanks, I can do a dozen bobbins in a hour without honing the HSS skew chisel I use.  Using tool steel tools, I have to stop and sharpen frequently, and only get half as many bobbins made in an hour.

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