Big Tube Fixture Jaw Machining and final build of my Spider-Mandrel

Machining the jaws for the large tube mandrel on the lathe and milling machine. For new viewers, this is a fixture to hold six to eight inch diameter thick-walled tube for turning operations on my Colchester 1800 lathe, giving me access to the full outside, both ends and parts of the interior of the tube of the full range of lathe tooling. I do the first test cuts, and a there is a MAJOR upgrade, inspired by a comment from Chris Maj.
This is the final part of the build. The next time Spider-Mandrel appears in one of my videos it will be in a supporting role as a part of my tool armoury. I've been amazed by the response to the two previous videos about this fixture. I hope this video clarifies the purpose and design decisions that led to its creation in a small, messy machine shop in the East Riding of Yorkshire on the island of Great Britain. You've probably never heard of either, and anyway, I'm from Lincolnshire.
I'm a cybersecurity architect and data network engineer, not a microwave radio engineer and definitely not a Proper Machinist. I learned machining from RUclips, so go figure!
"Useful" comments are provided by my terrible, artificially intelligent, totally snarky sidekick AIMEE. She's got to go. Her image was created on the slightly worrying thispersondoesnotexist.com
Chris Maj has a totally brilliant RUclips channel which is definitely worth a sub. / @chrismaj
Images and clips not created by me are either public domain, out of copyright, or include a name or copyright statement, or are listed below:
NASA apod.nasa.gov/apod/ap180219.html
soundbible.com/1997-Cha-Ching...
Keith Edkins / Tumbledown shack / CC BY-SA 2.0
Lively Lumpsucker and other tracks by the most excellent Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
creativecommons.org/licenses/b...
Chapters:
00:00 Rings. Big Rings
05:56 Groove Micrometer Time
12:14 Chamfers are important
19:22 Glue chuck and washers
31:05 Good fixturing avoids broken tools
36:20 Boring bar action