It’s common for this kind of chuck to be the part that spins fast in a lathe, but you can also mount it on a turntable and use it in a milling machine. In that case it turns slowly while a milling bit spins fast next to it. That is, for example, how I made the rotation turntable we use for a lot of our photography work.
Location: Farm
Have you used this tool? Think my description is all wrong? Have a better example? Comment now with any thoughts you have about this tool!