Thursday, July 14, 2016

An update on Irish tension

On pages 214-215 of Alden Amos's Big Book of Hand spinning, Alden discusses single drive - bobbin lead flyer/bobbin assemblies, noting on page 215 that a small flier (e.g. AA's # 0 competition flyer.) will allow spinning carded Targee at ~19,000 ypp.

In fact, with the addition of ball bearings to such a flyer, it can spin such 58 count wool at its spin count of  ~32,000 ypp  (65 m/g.). I did so yesterday.   This morning my # 0 flyer running single drive, bobbin lead was spinning 80 count Rambouillet at ~ 45,000 ypp (90 m/gram).  Spinning "fines" at their spin count can be done with Irish Tension.  How fine will Irish Tension spin?  I have no idea.  It tends to be a fine meditative process.

I was spinning worsted using the accelerator, so I had more speed than I could use. There were 2 limiting factors. The first was that I had to draft  "inch worm" style. It was the drafting that slowed me down. The fastest bobbin speed that I could keep up with was ~1,000 rpm.  The second factor is that with single drive - bobbin lead, take up tension increases as the cube of the rpm, so fine singles tend to break at higher speeds.

 Differential Rotation speed allows  different, and much faster, drafting styles for both woolen and worsted spinning.  And DRS isolates tension on the single from the speed of the  flyer/bobbin assembly.  With DRS, the single being spun can be kept at low tension, even when spinning at very high speed.

DRS also allows controlling the spinning process by changing the flyer whorl, rather than changing the whole flyer/bobbin assembly.

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