Plying such thin, wriggly singles is a pain if you don't have a tensioned lazy kate and I don't have one. So I need some way of adding more friction to the system so the spindles don't immediately unwind on me when I yank on them a bit.
I've already added an "eye" to my untensioned lazy kate so that at least the singles all get led to the same point and don't end up winding around the kate's axles, see picture below. This helps already. I've also clamped the kate to the coffee table.
[note eye that 3 singles go through]
I googled around and there is something called a "tension box" that weavers use to control their warp yarns (during some mysterious weaving step) which looks like just the ticket. I don't have one of these either, but I thought that I could rig something pretty similar in a pinch just using the back of one of our kitchen chairs. Basically you need a bunch of dowels that you wind the singles through. Below is my solution!
[kitchen chair as tension box]
This arrangement has really, really helped. The singles don't unwind from the kate too fast now, it's very controlled, and the plying is much easier and more uniform. This means my yarn is better!
[success! 520m of 3-ply southdown!]
I am very happy with the end result: a grist of 440m/100g - lightweight fingering, just what I was aiming for, with a nice tight ply. Yay!! I am getting better at spinning so the yarn is more consistent; fewer spots where it is too thick or too thin (they are still there, though!). More plies means "more averaging": the thick/thin spots become less and less visible the more plies you use. I'd really like to be able to spin thin enough for 4-ply sock yarn. That'll be my next goal: 120WPI singles....but not until I make some changes to my spinning wheel for more speed.
I still need to learn how best to handle broken singles. Right now I'm just knotting them and continuing to ply (I figure I will deal with them during knitting), since there are not that many of them.
Now I am looking forward to knitting up a pair of winter cycling socks!