i just successfully threaded my first bolt, only to discover i was
threading left hand threads. aaargh!
how can i thread right hand threads while starting the thread at the
bolthead?
how can i hold the bolthead with the tailstock and center the end of
the bolt with a live centerin the spindle?
i'm thinking about grinding a tool to cut threads upside down.

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On 2 Dec 2003 10:19:32 -0800, (Ben) wrote:

i just successfully threaded my first bolt, only to discover i was
threading left hand threads. aaargh!
how can i thread right hand threads while starting the thread at the
bolthead?
how can i hold the bolthead with the tailstock and center the end of
the bolt with a live centerin the spindle?
i'm thinking about grinding a tool to cut threads upside down.

xxxxxx
xxx
x
xxxxxxxxxx versus


xxxxxxxxxxxxx
x
xxxxxxxxxx
Upside down is correct. If you change the direction of feed then you
must change the rotation which means upside down tools. If you want
the same thread.

Part of the fun of cutting threads is working up to the bolt head, and
stopping just before you crash! Usually people use a rear mounted tool and
run the lathe backwards if this is a big issue. Using an upside down tool
and running backwards will tend to lift the carriage off the ways, which is
bad. Often there are no gibs to hold the carriage down, just the normal
cutting force.

Center drill the bolt head for a live center in the tailstock, hold the
off-cut portion of the shank in the lathe chuck, thread normally from the
bolt head as far as you need and then chamfer and part off the bolt.

Brian


"Ben" wrote in message
om...
i just successfully threaded my first bolt, only to discover i was
threading left hand threads. aaargh!
how can i thread right hand threads while starting the thread at the
bolthead?
how can i hold the bolthead with the tailstock and center the end of
the bolt with a live centerin the spindle?
i'm thinking about grinding a tool to cut threads upside down.

xxxxxx
xxx
x
xxxxxxxxxx versus


xxxxxxxxxxxxx
x
xxxxxxxxxx

Upside down is correct. If you change the direction of feed then you
must change the rotation which means upside down tools. If you want
the same thread.

Or, cut with the tool on the back side of the work. Then its right side up
and easier to see what you're doing.

Karl

The direction of travel of the threading tool was just backwards. Throw the
tumbler gear into the other direction and all will be well.
Then again, make up left handed nuts to go with that bolt and really mess
with the minds of those who come later trying to take your stuff apart.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works evevery time it is tried!

"Karl Townsend" wrote in message
link.net...

Upside down is correct. If you change the direction of feed then you
must change the rotation which means upside down tools. If you want
the same thread.

Or, cut with the tool on the back side of the work. Then its right side up
and easier to see what you're doing.

Karl


And then reaction force is pushing the cross slide down into the bed instead
of lifting it. My gibs can take cutting on the back side, but bind up if I
run the tool upside down.

StaticsJason

Bob May wrote:
The direction of travel of the threading tool was just backwards.
Throw the tumbler gear into the other direction and all will be well.
Then again, make up left handed nuts to go with that bolt and really
mess with the minds of those who come later trying to take your stuff
apart.
OOoo - Nasty! - I love the concept - providing that you remember what you
did when the time comes to take it apart yourself. (GBG)
Now *that* is the stuff of great embarassment.
Ken.