Tuesday, April 01, 2014

The Accelerator Revisited

It has been weeks since I made another version of the accelerator. With this version I have spun, plied, and cabled miles and miles of yarn.  It works.

With the accelerator, the Ashford Jumbo flier (ST) will run at between 1,000 and 1,600 rpm.  I was very pleasantly surprised at how well it works, running at over 1,200 rpm.   The Ashford Lace Flyer (ST) will run at just under 3,000 rpm. And the AA competition flier will run fast enough to spin woolen fines at 300+ yards per hour. This is all  much faster than I ever approached just using tiny whorls - even with elaborate bumpless drivebands and careful attention to whorl profiles.  All in all, everything runs about twice as fast as I could get it to go without an accelerator wheel. On the other hand, I do have a double treadle wheel and am willing to treadle hard.  I expect that a single treadle wheel would only go half as fast.  I also go through drivebands fairly rapidly and I use a lot of driveband dressing.  I keep an oil bottle of Royal Purple handy and I oil everything frequently.

This is not to say that driveband slip is always bad.  It can also act as a clutch in single drive systems to help avoid break off when spinning higher grist singles.  Another advantage of DRS DD is being able to come up to full spinning speed much faster without breaking the fine yarn.

I also have given up understanding why modern wheel makers have become so fixated on screw devices to control the tension of  drivebands.   Such devices make it hard to get reproducible levels of drive band tension, and almost ensure high loads on flyer bearings.

 The Ashford standard DD fliers will run at near 1,800 rpm with the accelerator.   Years ago, when I first tried to get the Ashford standard DD flyers to go faster, I thought the limiting factor was that the flyers were not balanced and that they had a high aerodynamic cross section. Now I think it more likely that the problem is that the Ashford DD axles flex at the joint with the flyer whorl and cause the vibration.

I took half of the heck array (hooks) out of the Ashford (ST)  Lace Flyer, and with ball bearings at each end, it runs twice as fast with an accelerator as it ever did without the accelerator. Without an accelerator, the drive ratio said it would go this fast, but it never did.    The new speed was a pleasant surprise.  I dislike having the whorls at the front so that there is a long barrel that the yarn must be threaded through.  

Somehow the net productivity of spinning on the Ashford Lace Flyer is not nearly as high as with the Alden Amos fliers.    Thus, these days, all the spinning of singles  is done on the AA fliers, 2-ply is made on the Lace Flyer which will hold full hank of  5,600 ypp 2-ply, and big stuff is assembled on the Jumbo.

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