Saturday, November 30, 2013

Trouble With Take-Up

The past ten days have been filled with baking, cooking, roasting, and dog sitting. Cakes, pies, sauces, turkey, potatoes, salads, and the regular dog walks. A fabulous way to spend time.

I spent the earlier part of November spinning and knitting. I finished spinning 2 pounds of wool/mohair roving that I’d purchased in October. I spun 6 skeins of 3-ply yarn. That means I filled 18 bobbins with singles. A marathon, of sorts.

As I spun the last 3 bobbins of singles, I noticed that the drive band on my trusty little Reeves upright wheel was looking ragged; it was fraying and going to break any second. Before spinning the very last bobbin, I took the pre-emptive step of changing the drive band. I cut off the old cotton band, and replaced it with a linen string. Now, I’ve changed bands on this wheel many times without mishap. But I’d never used linen before. Just cotton.

I merrily started spinning the last of the fiber for this large project. The first few minutes went as smoothly as always, but then I started having trouble with the take-up tension: the singles were not going on to the bobbin. How annoying.

Take-up tension – how hard the wheel is pulling on the yarn you are spinning – is simply a matter of friction. If the take-up tension isn’t right, then one of two things is wrong: either you have too much friction where you shouldn’t have friction, or you don’t have enough friction where you should have friction. Solving the problem is just a matter of friction trouble-shooting.

Because I’d just – just – changed the drive band, I assumed that it was the likely culprit. My first step was simply to tighten the drive band (thereby increasing the friction of the drive band on the whorl and bobbin). That did not work. No amount of tightening had any effect on take-up tension. How could that be?

I then considered that the linen string was not a good choice for the drive band (insufficient coefficient of friction, perhaps?). So, I changed the drive band again, using a cotton string instead.

Still, the take-up tension was wimpy. Sheesh! I had only one more bobbin to fill. I was so very close to finishing this spinning project. How frustrating.

Since it appeared that my problem was not the drive band, I considered the possibility of there being friction where there shouldn’t be friction. I removed flyer, unwound the whorl, removed the bobbin, wiped off the shaft of the flyer, and re-oiled the flyer. I was about to put the bobbin back on the flyer but decided to examine the bushings on the bobbin. Nothing obvious. I then got out a q-tip cotton swab and poked it into the ends of the bobbin. Whoa! I cleared out a gob of grimy fiber out of each end of the bobbin!

After I re-oiled the bobbin and put the bobbin-flyer back in place, all was right with the world . . . and with my take-up tension.

In all my years of spinning, I’d never had this happen. This gob in the bobbin. In my assumption of the guilt of the drive band I overlooked a simpler problem. Here’s hoping I won’t do that again. Systematic trouble-shooting is better than assuming.