Tom Johnson broke a chuck spring and George Langford offered to make a new
one.

Hi Tom,

An easier way than waiting for George to wind you a spring may be to take
the chuck to your local locksmith.  Locksmiths have the most amazing stocks
of small springs, of all lengths, diameters and strengths.  Worked for me.
The guys in the shop got intrigued by the problem, I left the chuck with
them for a couple of hours while they found time to scratch around, anf
picked it up working better than ever.  Cost less than a $, and an Aus $ at
that.

Regards,

Tony B
Hobart, Tasmania