That's what I did for a living for 25 years, though I never tried to do this. I've seen the same thing done on a CNC milling machine, but not a simple turret lathe.
I worked out what he was doing as soon as he started boring it out, but the hot glue trick floored me - I would never have thought that would work!
Glad to see someone keeping it old-school. Thanks for posting!
Yeah the hot glue was amazing to me too. It's amazing that that is enough to hold during machining. I bet that would go super crazy if the glue didn't hold. Took me until the end to understand the concept of how he was boring it out to make the cubes though.