Double and Single Drive

Finally, the sisters met.

We are calling them Blondie and Redwood (Red for short). Hopefully this won’t be too offensive to anyone with red or blond hair, as both of their spinners are brunettes.

Setting them side by side is the easiest way to tell the difference between the two flier types. For starters, Blondie (single drive only) has the whorl attached to the flier, and the whorl is closer to the spinner. Red (double drive) has a removable whorl at the back of the flier, because the drive band has to be able to attach both to the whorl and the bobbin.

The way spinning works is fairly simple: the drive band (the white string) goes around the drive wheel (the big wheel) and the flier (the thing with all the hooks). The yarn-in-progress feeds through an orifice at the front of the flier, allowing it to be spun around without getting tangled. The yarn is wound onto the bobbin by virtue of the fact that the bobbin is spinning at a different rate from the flier. This speed differential can be accomplished different ways, which is why you have different kinds of wheels.

Observe Blondie. She’s a scotch-drive-only setup. The drive band spins the flier, and the bobbin is made to go slower than the flier by a brake: the brake is a little plastic cord you can see going over the back of the bobbin, attached to a hook. On the other side of this assemblage, there’s a spring and a handle which allows the brake to be tightened or loosened, increasing or decreasing how hard the bobbin pulls on the yarn in progress. This set-up – drive band on whorl, brake on bobbin – is called “scotch tension,” and is one of two ways to do single drive.

Red is primarily a double-drive. With double drive, as it’s set up now, the drive band is twice as long, going once around the flier whorl and once around the bobbin whorl, and twice around the drive wheel. The difference between bobbin and flier speeds is accomplished by the fact that the bobbin whorl and flier whorl are of different diameters.

However, this wheel can also be set up for either of the two types of single-drive. You’ll notice the spring set up that is just sitting idly at the near side of the mother-of-all? That can be strung over the the bobbin whorl or the flier whorl. If the brake goes over the bobbin whorl and the drive band goes over the flier whorl, that makes scotch tension or “flier led” tension. If the brake goes over the flier whorl and the drive band goes over the bobbin whorl, this is called “bobbin led” tension, and has much the same effect. If you look at the above picture of Blondie, you’ll see that the whorl on the flier has three different circumferences, while the flier whorl on Red has only two. To get the smallest circumference (and fastest speed) on Red, you have to set up bobbin-led single-drive tension.

This post is sweet revenge, brought to you by all my friendships with engineers.

Mom and I spent yesterday afternoon geeking out about spinning. I got to see all mum’s new handspun, and discuss drafting techniques and wheel setup. I filled a bobbin through Avatar, mostly spinning like this:

This is my first attempt at woolen spinning, and I’m pretty proud of myself for figuring it out. I need a real class, though, because it’s rare that I could entirely let go of it. Really, I mostly did a semi-supported thing like this.

Sometimes my left hand doesn’t have to do anything, an I’m more or less woolen spinning. But it’s handy for my hand to be there, so I can smooth or pick out nupps and VM, and do a little drafting when I run into felty bits.

We do still have a brunette in the family. Doris came to mum’s house to live for a while, and Bethany learned to treadle.

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