wrote in message On Oct 16, 8:27 am, "Phil Kangas"
wrote:
"Harold and Susan Vordos" wrote in message "Gerald
Miller" wrote in message
snip-----

Came by a couple of 1/2" LH thread nuts, so decided
to
make shaft
adaptors for motors with 1/2" shafts since all of
the
available ones
are RH thread. I got to the point of cutting the

threads, did my first

pass and checked the scratch against the mating male
thread - didn't
quite agree; the original thread was 1/2 - 24, so
now I
have a funny
spot every 6th crest.
Gerry :-)}
London, Canada

Heh!
Can't tell you how many times I've done that. Nice
thing
is, the "funny
spot" virtually disappears if you make a habit of
making
your first pass a
shallow one. A thou or two is plenty.

In spite of my years of experience, or maybe because
of
them, dunno, I
always take a shadow cut when chasing threads. Just
deep
enough to allow a
match with the pitch gage. It's too damned easy to
miss
a setting,
especially on my lathe, where I've messed with the
ratio,
having cut all the
feeds and threads in half. I like light feeds for

finishing and found my

Graziano too fast in that regard. I've lived with
the
changed ratio since
1967----but still screw up occasionally. Maybe a
function
of getting old,
eh?

Harold

A couple years ago I made a thread toy called a puzzle
nut.
It was cut
at 9 tpi double start. Since this is an odd number
thread
and it was
being doneon a SB model A 9 inch I used the numbers on
the
dial for one groove and the unnumbered marks for the
other
groove.
Did both the male and the female this way. The nut was
cut
in half
and red loctited to the ends of the male section. It
worked
nice and
looked like 18 tpi but the nut moved fast from end to
end.
So then
I decided to try a triple! For that I started with a
longer
rod with a
dowel pin in the side so it would rest against a chuck
jaw.
Cut the
groove at 9 tpi as before but for the next groove I
moved
the rod pin
to the next jaw and then the third jaw to make a triple
start thread!
This one was really fast moving! Sure acted strange
rolling
than nut
back and forth as the thread looked to be fine at 27 tpi
but
really
hauled ass from end to end! That was fun......;)
phil


Phil,

How did you make the triple start nut?

Wolfgang

The same way as the male, by using a chunk of round bar
longer than
the needed nut with a pin sticking out of the side at the
end. The pin
is placed against one jaw and the chuck face at each step.
The nut
itself was about 3/4 inch long and the end nuts were about
3/16 long.
If I remember correctly the thread diameter was 5/8 and the
nuts
were one inch O.D. and round, no flats. Overall length was
about
2.5 inches. I gave both away as gifts.
A bit fussy but it worked! A real schoolhouse lesson for
sure.....;)
phil