Making a Custom Acme Tap in the home workshop

Holbrook lathes liked to use 9/16 x 8 Acme threads for their cross-slides. That isn't an easy tap size to find, so this video documents my attempts to make one.
This is the first tap I have tried to make, I learned a lot, and ended up with something that cuts threads.

Видео Making a Custom Acme Tap in the home workshop канала andy pugh