How many shafts does Zhou Pu's three-generation spinning wheel have?

Zhou Pu's third-generation spinning wheel is one of the traditional hand-made textile tools in China. Zhou Pu's third-generation spinning wheel is characterized by its four-axle structure, including a main shaft and three auxiliary shafts. The main shaft is equipped with a spinning cage, and the auxiliary shaft is used to control different movements of the spinning wheel, such as yarn stretching and winding. This structure enables the spinning wheel to perform multiple operations at the same time, which improves the production efficiency.