at 1:30:10 you prop the v-block on 2x4, keep that center bolstered or you'll be unbending that base everyday. Oh lawdy, once you start machining you'll be amazed how vast and versatile the tooling library and various workholding will take up space. It's a perpetually growing project shop in itself. The rabbit hole's deep, and the precision aspect of it requires precision tooling, and that's either time to make it, or money to pay for it. Gotta be as organized as possible if you don't want to spend half-days looking for the drills, taps, reamers... just to get started. I'm sure a ton of projects can be done accurately with random stuff, but being hours or days maybe into a part and messing it up SUUUUUX. It's not always a dimensional problem, you might have a tool shatter and ruin a feature or get stuck in the metal. Be prepared for patience.
You said it , make a cutter blade that's strait across like a cleaver or at least much less point angle so it doesn't change its path when it penetrates the bottom inside.
the blade pointie 180 degree just enough topenetrate the ring than let it go to flat, that way 10'' stroke should be enough to go trough all the way thru,
