David explains:

"Having just received a pair of castings for the George H. Thomas screw cutting tool holder, I wondered if I could make it automatic where it would self-extract instead of having a lever to extract the tool. If you are working up to a length you need to wind out the tool at the end of the thread being cut, reverse direction or disconnect the leadscrew and traverse to start of thread. I thought that if the retract could be made automatic I can run the lathe at a faster speed which helps with cutting finish and time to cut thread."

Full details of this device will appear in MEW 328 (out soon!) and MEW 329 the following month. You can pre-order both issues here: MEW Pre-orders and back issues.

To whet your appetite, here are some videos from David: