It' s lightweight and easy to set up and take apart. It could be packed in a suitcase easily if you're traveling to a knitter's conference or seminar. The susan isn't modified in any way, so it can go right back in the kitchen when you're done. It works very well with my homemade ball winder.
Step 1: Supplies
Note: "lazy susan" is an Americanism for a rotating tray or carousel. These are commonly available in the kitchenware section of retail stores. Prices start at about $4US and go up depending on size. Mine cost $2, but I bought it several years ago on sale.
Step 2: Preparing the Hangers
You may or may not need the pliers for this step; depends on how strong you are and how well your hangers are soldered at the twist. Some hangers are made of a more brittle metal, and a piece may break off during this step. Don't worry, there's plenty left for what you need.
Step 3: Shaping the Hangers
My lazy susan has a lip around the edge, so I put a slight curve in the bottom. This makes sure that the hanger has some contact with the bottom of the susan when it gets taped down in the next step. If your susan is completely flat, you won't need the curve.
Step 4: Final Assembly
Now tape the other one down crosswise to the first, so they are perpendicular. Add tape where needed to keep them upright.
Step 5: Adjustments
To adjust, pull or bend the wires upwards and/or outwards as shown by the arrows. Ideally, you'll want the wires spread just a little bit wider than the diameter of your hank. When you place the hank on, the springiness of the wires will pull it gently outwards keeping it from slipping down.
To use with bigger hanks, bend the arms as shown in the second photo.
My susan is lightweight plastic. When the yarn hit some resistance, the susan would sometimes slide towards me or even backspin a little bit. I solved that with a couple cans of soup spaced evenly for balance. The extra weight helps control the spin and adds stability.
I haven't had any problems, but if your yarn snags on the ends of the arms, you could try:
slipping a piece of plastic tubing over them (aquarium air tubing, maybe?)
wrapping with masking tape
dipping in plastic dip coating sold for hand tools
If you have an old turntable around, you could tape your swift to it, and have a powered swift for winding hanks.
If I had money to waste, I might use this idea to make a nice looking swift with a wooden susan and heavy copper wire. The wire could be screwed down with some nice looking brackets or metal plates of some sort.