What type of machine did Leonardo da Vinci design to automate the winding of thread?

Leonardo da Vinci designed an automatic bobbin winder to automate the winding of thread. The machine was intended to place thread evenly onto a bobbin, improving a repetitive textile task through coordinated mechanical motion.

Leonardo studied textile machinery and other devices that could replace or reduce manual labor. A bobbin is a cylindrical or tapered core used to hold thread or yarn. Winding it evenly helps prevent tangles and makes the material easier to use in later spinning, weaving, or sewing processes.

The device should not be confused with a spinning wheel. A spinning wheel twists fibers into yarn, while a bobbin winder transfers already formed thread or yarn onto a support. It is also different from a loom, which interlaces warp and weft threads to make fabric.

Leonardo’s textile designs illustrate his interest in automation and continuous motion. As with many notebook inventions, the surviving drawings document a proposed mechanism rather than a confirmed factory machine used during his lifetime.