Friday, December 17, 2010
WATCH CASE THREAD CUTTING
A brief description of the tool is as follows. A bushed carrier is mounted to the lathe bed behind the headstock. In the carrier, a ground rod is able to slide with great ease and precision. On the far end of the rod is mounted a slide with a tool post, in the tool post, a hardened and ground thread follower is mounted. This follower rides against a threaded die that has been mounted on the headstock spindle. On the other end of the rod is the cutter arm. As the whole assembly is rocked forward, the follower picks up the threaded die and carries the rod with the cutter towards the headstock, creating an identical pitch thread on the work. As the follower slide is withdrawn, a deeper cut is made, this is the tool in-feed.
The piece being made is a giant 22 size wristwatch case. I will be posting more on this watch again.