Wednesday, November 19, 2014

Revised Geometry

Last spring, as I started using accelerator wheels, the advances came fast and furious.  And then things stabilized for months.  It was a time of learning to use the tool.  After all, while I have seen drawings of such tools, I have never seen such tools actually being used by any other spinner.

Anyway, for the last month, I have had thoughts that the geometry could be better. First trials of first prototype are very promising.  What I had thought to be a reasonable rate of production is clearly the bottom end of the reasonable rates of production that can be easily achieved when the tools are properly adjusted.

In this version, it is about 30" or 36" from the orifice to the drafting hand.  The longer distance between drafting and bobbin allow more distance for the single to "settle", allowing the production of a more uniform yarn.  And, there is slightly more tension in both sets of drive bands, limiting drive band  slippage.  Top  flier speeds did not change much, but speeds of 3,500 rpm are quieter and less effort, so that I am routinely able to spin much faster.  Now, I can hear the movie while spinning 5.600 ypp/ 12 tpi woolen singles at more than 7 yards per minute.  Worsted at that grist goes at ~10 yd/min.

I am surprised at how much a 6" change in geometry changes the system.  I know I should not have been surprised given that even very tiny changes in whorl diameters dramatically change the system.

My two take away lessons from this experiment are 1) the importance of wheel/spinner geometry to yarn quality; and, 2) that a loose and self-adjusting system can run smoother and with less vibration than a system built to feel solid and well built when it is not running, but where vibration generated by the knot in the driveband can propagate through the system.

A system using relatively crude bearing technology can run at flyer/bobbin speeds in excess of 4,000 rpm. It is a matter of isolating and damping vibration.

I am sure that the rubberneckers will take this post to mean that I have not known how to adjust my wheel - despite that fact that I have been spinning twice or 3-times as fast as they have been. Now, if they want to keep up with me, they will need to spin much faster.  Good luck to them.


Anonymous said...

1) I can't imagine why you would butcher that wheel rather than just buying a wheel that was designed for the type of yarn you want to spin.

2) I can't imagine why you'd want to spin mediocre yarn more quickly, especially since you never actually do anything with said yarn.

Are your finished products are as difficult to photograph as your magical singles? Are you knitting new clothes for an emperor?

Given how boastful you are about all of your other (imaginary) successes, I can't imagine you wouldn't be showing off your finished knitted/woven items as well.

Aaron said...

Most commercial wheels are designed to insert twist at no more than 1,000 rpm. None are designed to insert twist at more than 1,600 rpm.

Just looking at the ratios, it appears that some wheels will insert twist faster, but when you put a tachometer on them, it turns out they do not actually go that fast. Mine does.

Ask around the folks that have the super-high ratio wheels. How long does it take them to spin a few pounds of high grist, high-twist warp for a bolt of fine woolen cloth?

Good yarn is yarn that serves its purpose. Yarn for a decorative shawl will be different than yarn for a seaman's sweater that must keep the seaman warm. Both will be different for the yarns spun to make woolen flannel, woven worsted wool cloth, or storm cloth.

You may not think much of a yarn designed to produce a fine nap on a woven fabric, but until you have produced a variety of wool flannels, you are not qualified to judge my yarns.

Anonymous said...

How do you know how fast strangers on the Internet spin?

You don't. Idiot.

Anonymous said...

I agree with you. Vibration is a huge problem with spinning wheels operative over 1600rpm. Improper balance, and air resistance I find to be the main culprits, however other factors such as bobbin clatter, drive band etc, have all proved difficult areas for me to fix.
Realistically, there IS no wheel on the market today that will spin the way you want to spin. Sure, you could probably twist the arm of a good wheelmaker to make it for you, but it may be prohibitive cost wise, if you can do it for cheaper.

I go for a slightly different approach with my wheels - I tend to ensure there are no causes (or as few as possible) of vibration,rather than damp them.

Aaron said...

By using, commercially available (wheel & flier) products, a bit of homemade stuff (Accelerator & Mother of All) and some vibration damping, I got a wheel that spins the way I want it to for much less than the cost of a custom wheel.

This morning, while I was spinning the bobbin was running at ~ 3,800 rpm, and the whole rig was quite enough that I could hear the weather channel.

Bobbin clatter in particular is easy to control. Often grease, rather than oil will take care of it. Then try Delrin bearings. As a last resort, the ball bearings sold for skate boards work if they fit the axle.

Aaron said...

Results of spinning competitions are posted on the Internet. The good judges describe the various yarns and measure grist. If you know grist, spinning style, and how firmly the yarn was spun, one can calculate twist. From twist and time, one can calculate how fast the spinning device was turning.

And, I talk to folks who do go there. These are guys with the eyes that can tell me if there was any custom work done on the wheel. If not, I know how fast the stock wheel will insert twist.