I've had a few requests for a how to on this, so here goes; I hope my explanation is helpful (my printed instructions are somewhere in my studio).
The Dharuma Home Twister plies different yarns evenly, for balanced color and/or texture distribution. Normally, when you knit with two or more colored strands held together, you get "runs" of color bands throughout your piece (crochet distributes color more evenly, due to the turning of the yarns with your hook).
On maintenance: I've had my little do-hickey since '86'; thank the ancestors. Although they're back on the market, they're not cheap. If you have one, treat it with respect. Don't make it do what it doesn't want to. It has a purpose.
One Picture, Is Worth A Lot, But…
Here's my experience. It obviously clamps to a table. The white cone ball-maker simply attaches and removes by turning it in the direction shown on the arrows. I don't use it as a ball-winder, as I found the switch from one purpose to the other on this, difficult to perform.
To assemble: Insert the separate metal winding attachment into the cutout in the base of the winder. The curlicue tensioner in the middle of this attachment, is for use with the ball winder only; for the twister, you are threading your yarn through the top hole in the attachment, then through the metal winder attached to the unit itself, and finally through the slits on the cone (see the previous paragraph on how to attach the cone to the base). Push down on the threads in the slit, especially if you are twisting together a lot of ends, so they don't fly off when you start turning the crank. You can crank in either direction, it doesn't matter.
Twisting The Night Away
Please don't be in a hurry to twist––that's a recipe for disaster. If you are diligent: Learn some color theory and its application to knitting and blending yarns, before twisting. If you are lazy: Twist and knit up very small (8st x 8st) swatches, adding and subtracting color and texture, until you come to a combo you like. If you're not into color at all: You can create gorgeous yarns by mixing textures. I like to mix a silk for sheen, a very thin mohair for an all over haze, and two wools for strength.
Don't turn the crank at light speed, or make large balls!! If your ball flies off the cone, or something else happens, you'll have too much momentum going to stop your hands quickly. Think quality, not speed. In my experience, 1 oz. size balls have been the easiest to make. Pull off the tail from the slit first, then remove the ball from the cone. Voilá! A neat center-pull ball. Have fun, Sherry C.!