Thursday, May 19, 2011

DIY: high speed production wheel for high grist singles

In 2009, I decided that commercial gansey yarns were not as good as what they could be and that I should spin my own. (These singles are about 5,600 ypp grist.)  After some thought, I bought my Ashford Traditional (Traddy) in April 2010.  By August, I wanted more speed.  The Ashford Lace Flyer Kit was a step in the right directions, but I wanted more speed. The Ashford DD Kit actually provided more speed.  However, it became clear that belt slip was the big problem and at higher flier speeds, was the dominate issue. Then, I became interested in higher grist singles and the problem became acute.

A very careful reading of Chapter 8 from Alden Amos Big Book of Handspinning, suggested that the solution was a "one-yarn"  double drive wheel, where a precise relationship between the size of the flier whorl, the size of the bobbin whorl, and the diameter of the bobbin core allow the use of a tight drive band with limited slip.  Thus, in this setup of a DD wheel, there are two drive bands suppling power to the flyer/bobbin assembly.  Such wheel setups were common from circa 1600 until WWI.  However, they are notably absent from the famous "Canadian Production Wheels."  And, such DD setups are not offered by any of the manufacturers that mass market spinning wheels. That is because they take some skill to setup and keep operating correctly.  However, that extra effort is repaid with real spinning ease and speed.

It looks like an ordinary "Traddy", but it is wicked fast.


Understanding "DRS", as the term is used by Alden Amos in his Big Book of  Handspinning (or Preistman's discussion of Saxony Wheels in  his 1925 Principles of Worsted Spinning) is critical to making this work.

An  Ashford high speed flyer whorl and bobbins made for yarns in the 5,000 to 10,000 ypp range.

I started by turning new bobbins to work with the high-speed  Ashford DD whorl at specific DRS for specific yarns with twist calculated for the bobbin cores.  These did not have any bearings, so they chattered and were noisy. However, they proved the concept and allowed me to spin 560 yard hanks of 5,600 ypp single in about 4 hours, which was  faster than I had been spinning such singles with the Standard Ashford High Speed DD kit, and was faster than I had been spinning those singles with the Ashford Lace Flyer Kit.  Moreover, the spinning of such singles on a one-yarn DD wheel was less effort and provided a more consistent yarn.   I was hooked.  What opened my eyes to the possibilities of the technology was a bobbin that I made with a DRS of 1.02 that allowed the effortless production of 30,000 ypp singles.  Yes, it was slow, taking a full 8 hours to produce a hank, but still, it was not something that I considered to be within the range of a first year spinner.  It was an epiphany.

Then, one of my Ashford flyer whorls warped and I had to replace it. Afterward, I knocked the warped  wood off of the steel core and epoxied a piece of walnut burl onto it and turned it down to a (flier) whorl with a diameter of  0.6275", which gives a flier ratio of ~35:1. However, the bobbin whorl diameter for a DRS of 1.02 is 0.61" for a bobbin ratio of ~40:1.  Since this setup is run with a taut drive band I get a useful 2,200 twists per minute from the bobbin, which allows spinning a 560 yards of firm twist 5,600 ypp in a couple of hours or 560 yards of firm twist 9,000 ypp singles in well under 3 hours.

Ashford DD flier with whorls and bobbins to produce yarns in the 5,000 to 10000 ypp range with firm twist. These have a wheel to bobbin ratio of 40:1.  They are very fast.

The required wood working tools are a small drill press, a small wood lathe, and turning chisels.  I cut the bottom of the flier whorls with the back of a skew chisel, and the bottom of the bobbin whorls with a skew chisel that has been rounded into a scraper.

The last sets of bobbins have either  plastic bearings from Ashford or sintered bronze bushings from my local industrial hardware store.  Both work, and I have not made up my mind yet as to which is better.

I wind off when there is half or a third of an ounce of single on the bobbin, and thus the bobbins do not need a large capacity, and there is a relatively small change in the bobbin diameter as a result of accumulated yarn on the bobbin to change inserted twist.  This program is for fine singles.  I have a little bobbin winder that supports very rapid wind off without taking the spinning bobbin out of the wheel.

My Traddy has vibration at about 1,600 rpm.  I put on a set of better hinges under the MoA, and I use a white rubber vibration damper under the tension screw, all of which help but do not solve the problem. I can either loaf along at less than 1,500 rpm or treadle hard and get the rpm over 2,000, when vibration dies down again.  Thus, I have a sweet spot for bobbin rpm between 2,000 and 2,200 which is fast with little vibration.

I had some problems with a prototype bobbin whorl swelling in unseasonably wet weather to the extent that it changed the DRS.  However, when both bobbin and flier whorls are made of similar materials (wood) , similar dimensions,  have similar finishes (oil/varnish);  then they expand and contract at similar rates and to similar extents and this ceases to be a problem.

In summary, this is an old, but recently neglected spinning technology that requires a good bit of knowledge and skill to implement.   However, it offers a way to easily spin very soft and very fine yarns that are very difficult to spin with any other technology, and it offers a way to spin  fine yarns very consistently and very fast.