Tuesday, October 13, 2015

Whorls

See https://www.academia.edu/11841581/Efficiency_and_technique_Experiments_with_original_spindle_whorls

A good spindle is faster than most modern spinning wheels!!

The factors are the moment of inertia of the whorl, the total weight of the whorl, the diameter of the spindle, and the weight of the spindle.  (http://www.feynmanlectures.info/ )

Moment of inertia determines how long the spindle will rotate.  The moment of inertia also controls how fast the spindle can be spun. 

The total weight of the whorl and spindle determines how thin a single can be spun.  Removable whorls, allows longer and finer threads to be spun.

A light weight, high moment of inertia spindle is good for fine worsted warp that with high twist.  The required inch worm drafting limits the total yarn production. The high moment of rotation gives time for drafting a good draw.

A light weight, low moment of inertia spindle is good for fine woolen threads, particularly with small diameter spindles to deliver very high spindle rpm. Fine spindles with low moments of inertia spun with a thigh roll can achieve speed of more than 3,000 rpm, allowing very fast production of  woolen yarns, where one hand controls the spindle, and the other hand drafts. It is wicked fast, and Karina Gomer  misses just how fast it can be. It is much faster than any portable wheel. For this, I like a metal blade.  Or, I like a very thin wood blade with a small (removable) brass whorl.

In either, case, a whorl that can be removed so the copp can act as the whorl, keeps the process fast  as the moment of inertia of the copp increases

Heavier whorls are good for heavier yarns.  Heavier yarns need higher moments of inertia to overcome the higher torsional rigidity of thicker yarns, and the thicker yarns can support greater spindle/whorl weights.  Thicker yarns require much less twist, and thus less rpm.

A good spinner will choose the right spindle for the task.  In the old days, spinners had a great many tasks. And spinners had a wide selection of spindles, and they know which spindle to use on a particular task.

Respect the spindle!  Know your tools!  Use the right tool for the job.

Karina Gomer misses the physics of spindle. She gets the generalities correct such as heavy whorls working for thicker yarns, but she misses things like diameter of the spindle as affecting total spinning performance.


1 comment:

Teri said...

My Bulgarian spindle is here: http://www.spindlitis.com/2013/05/finally-got-my-new-spindle/

It was clearly loved as they put a lot of work into those repairs. I don't really use it because it's just too heavy for me.

I've been fascinated by Turkish spindles. I discovered that I can turn out a low twist yarn. I work mostly with longer wools and they can be harsh as a high twist yarn.

Picked up on how to spin cotton when an Ethiopean woman showed me her spindle. It was made of gourd, with a cane shaft and a staple for the hook. Started spinning supported then used a thigh roll for extra twist. I do like spindles made of pretty wood, but they aren't keepers if they don't spin well.