That's pretty crazy. I appreciate his attention to detail. Kinda reminds me of
this fella on youtube who makes driveable scaled tanks. His gearboxes are pretty impressive considering he makes them (cogs n all) without a lathe or a milling machine.
Come to think of it, trying to make a (much smaller!) RC tank was what got me seriously started on the whole hobby engineering thing. I found out about what lathes are for on reading how to rebore bought pulleys, and googling around led to great websites like this one. Previously i'd been sort of frustrated and disappointed by all the popular (and crap) 'make/ hacker/ whatever' things that are all over the internet, where nobody really says
how they made a thing, and as a result most my projects reached dead ends that I chalked up to not being clever enough. Including that RC tank. I've got the hull taking up space somewhere in my garage. Maybe i'll get back round to it some day.