As a retired machinist, I'm following and enjoying this series of videos. I am a bit shocked that so much trust is put in digital calipers, particularly in this #3 video, on the crank and bushing. If our hero doesn't own micrometers, I'd be shocked. I think I have 3 or 4 0-1" micrometers; alas, none are metric.
Also interesting that the bushing was drilled, bored, and reamed in a 3-jaw chuck. I'd prefer bored soft jaws or better yet, collet chuck, to keep the bore rounder after removal from the chuck. When I was an engine lathe operator at Boeing 747 experimental shop, I was very fussy about getting parts round...despite our crappy lathes.
I also found it amusing that the CAD drawing turned out to be wrong...something I struggled with when I was working. The CAD drawings were commonly WRONG, or dimensioned from all sorts of strange and useless places, so I had to bug the "engineering department" for useful information. My opinion is that CAD guys sometimes don't spend enough time looking at the drawing, unlike manual drafting. It's important to remember that there's always a way to screw things up!
I learned to always be suspicious, after getting a package of "planning", drawing and material on one occasion. The customer's drawing said "any aluminum", but the material I got was 1018 mild steel. Good thing somebody (me!) was paying attention. Thankfully, all that is 11 years in my past!
Steve