Hallo Tom & helical-minded Galoots !
Tom Johnson lamented:
> In a clumsy attempt to tweak the spring on a chuck so that the
> jaws close evenly, I broke the spring (hung head here). I still
> have the pieces, but am wondering what the correct process is for
> getting / bending spring steel wire without MORE broken bits of
> wire.
A very long time ago, I volunteered to get into the spring-making
business, as I have had the necessary tool and a large selection
of spring wire (from another, long-forgotten project). The tool
is a simple mechanism that applies lots of drag and some leverage
to force the wire to curl around a rotating mandrel, all the time
under quite a lot of tension. The combination of tension plus
bending causes the wire to lose most of its tendency to uncoil.
I know the principle as the "associated flow rule" but that's
the subject of another day. Peening the corner of a bent angle
is another handy use of that rule - the angle stays put afterwards
if you cause all of its corner to be plastically deformed while
being held in the desired position. Todd may corroborate this;
if he doesn't, then it won't work.
Simply bending the finished spring is an exercise in frustration,
as there's no tension to go with the bending. Yagotta get it
straight from the beginning. Springs that buckle (aren't straight
no more) got that way 'cause they don't fit the holes in the jaws.
Too big, and they won't fit down inside when ya close the jaws. Too
small, and the spring buckles before the jaws get anywhere near
each other, and then the buckled part gets pinched. About one-third
the chucks made have the latter problem; one-third the former. The
remaining third are so rusty you can't move 'em at all.
This time, I solemnly promise to take a stab at making the first
such set for the one optimistic Galoot who already sent one in
for duplication, and I'll report after the weekend on my progress.
This doesn't have to sound so hard ...
Best regards,
George Langford, still at work in SE PA, cooling hissownself
(not the SEM this time) down after a day of panic in the mines.
amenex@a...
http://www.amenex.com/georgesbasement/
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