Handmade bow lathe - for turning metal without electricity

When I saw the bow lathe video's on ‪@Clickspring‬ , I was amazed by the accuracy that could be achieved with such a relatively simple device. I often avoid any turned parts in my projects, simply because I do not have a lathe for turning metal. However, after seeing those videos, I decided to make my own interpretation of the bow lathe as demonstrated by @Clickspring⁩. More specifically, I need a special bronze nut for a guitar truss rod that I plan to make, and having a lathe for this job is ideal. The turned piece of bronze in the end of the video will eventually become this nut.