JWho wrote:

HUM! I think I see what is meant now! One can work on a rod longer than
10" as long as it is 5/8" thick or less, correct? Assuming that is correct,
then your points on it being more and more wobbly as the rod got longer
makes perfect sense. Right now, I can only think of two parts I would ever
make, and neither is longer than 10". Before this, I thought every rod had
to be inside the two centers.

Actually you can't work a thin rod anywhere near the capacity length of
the lathe, because it will flex and chatter, rubbing against the tool
rather than cutting smoothly. You can probably only turn something a
few diameters long that is hanging out of the chuck, a bit longer if it
is also supported at the tailstock end. With something really long and
thin, you could work an area near the headstock, and a shorter area
real near the tailstock center, but not in between. And you'd have
trouble drilling the hole for the tailstock center, since you couldn't
support the work near where you'd be drilling.

I'm going to guess that for half inch stock, the practical limit for
chuck support is less than 3" maybe 4.5 or 5" if you support the other
end with the tailstock. Could be wrong though, lathe has been in
storage fora few years.

Incidentally, long piece hanging unsupported out of either end of a
lathe's headstock can be quite dangerous - either the end you are
working on, or spare stock hanging out the other side. They invariably
flex, and the more they flex the more the rotation makes them flex even
more - with the result that they can end up flailing around whacking
expensive stuff like you, crashing into the bed, or in an extreme case
even knocking the machine over.