newbie question

Hello, All!

Boy, I've never been on a list before where the lurkers got so much
attention! Makes me feel wanted. :-)

I haven't contributed because I don't have a whole lot to say as yet. I'd
love to do some of this stuff, but I have so many other things in the queue
ahead of it that I'll be happy if I get to it before retirement. :-) To keep
my metalworking jones fed, I'm working my way through the Gingery series.
(See the Lindsay Books website)

This might qualify for the eventual FAQ, except I've never seen it
addressed. What in the heck is so great about ball screws, that make them
worth so much? Why are they so much better than Acme or regular,
triangular-profile screw threads? Do they "work" differently from other
threaded screws? And are there some kind of inner "works" to a ball nut (is
that a proper term?)?

Thanks in advance -

--dan fox