On Sun, 27 Dec 2020 11:25:40 +0000, The Natural Philosopher
wrote:

snip

It would be amusing to design one using a PIC or somesuch and a small
electric motor with a worm drive so that you minotred a 'delta peak' in
current drain and when he nut cracked and the current fell, it backed
out of it all.

Yup, that was my 'Electric' design variant, along the lines of this
one:

https://www.youtube.com/watch?v=g0bUvW0QcJ0

But in the form of a self contained 'battery hand drill'.

Or you could even have a strain gauge built under the anvil part,
giving you a more direct reading of the load (and so removing any
friction / aging issues in the drive).

Cheers, T i m