HI ALL

I need to make a dozen ball nut adapters, requiring a 15/16 - 16 tpi
internal thread

first thought was a single point, small diameter rotating tool. Graduated to
what was on hand

a 3/8 - 16 tpi tap, then I ground off all the other flutes except for one
untouched row.

mounted this in a mill, did a circle command & included Z - .0625

on each pass the entire hole was threaded @ once as Z moved down 1 pitch.

8 passes later the part mates great!

I always wanted to try this & now I'm enthusiastic.

My question is, What other tooling besides the correct tap & what seems
expensive Thread milling tool

or methods do you use, I could have done this on the lathe semi manually but
this would take more time as

I could not just let it run & walk away. ;-)

I also want to do 1/4 - 20's & 3/8 -16's but I guess that's really pushing
it.

Is there a recommended way?

Peter

You can buy a 15/16-16 tap for not much money

"Peter Kiproff" wrote in message
.. .
HI ALL

I need to make a dozen ball nut adapters, requiring a 15/16 - 16 tpi
internal thread

first thought was a single point, small diameter rotating tool. Graduated
to
what was on hand

a 3/8 - 16 tpi tap, then I ground off all the other flutes except for one
untouched row.

mounted this in a mill, did a circle command & included Z - .0625

on each pass the entire hole was threaded @ once as Z moved down 1 pitch.

8 passes later the part mates great!

I always wanted to try this & now I'm enthusiastic.

My question is, What other tooling besides the correct tap & what seems
expensive Thread milling tool

or methods do you use, I could have done this on the lathe semi manually
but
this would take more time as

I could not just let it run & walk away. ;-)

I also want to do 1/4 - 20's & 3/8 -16's but I guess that's really
pushing
it.

Is there a recommended way?

Peter

suggest posting this to alt.machines.cnc

i know that they make thread mills for really small holes

Very innovative solution. Doing an unusual job with what is on hand
shows real use of the old gray matter. Cheers!
Bugs

On Sat, 31 Dec 2005 02:48:01 -0500, "Peter Kiproff"
wrote:

HI ALL

I need to make a dozen ball nut adapters, requiring a 15/16 - 16 tpi
internal thread

first thought was a single point, small diameter rotating tool. Graduated to
what was on hand

a 3/8 - 16 tpi tap, then I ground off all the other flutes except for one
untouched row.

mounted this in a mill, did a circle command & included Z - .0625

on each pass the entire hole was threaded @ once as Z moved down 1 pitch.

8 passes later the part mates great!

I always wanted to try this & now I'm enthusiastic.

My question is, What other tooling besides the correct tap & what seems
expensive Thread milling tool

or methods do you use, I could have done this on the lathe semi manually but
this would take more time as

I could not just let it run & walk away. ;-)

I also want to do 1/4 - 20's & 3/8 -16's but I guess that's really pushing
it.

Is there a recommended way?

Peter

Thread milling cutters are expensive, as you said. But you can buy
thread milling inserts pretty cheap. And make your own cutter body.
However, a 1/4-20 inside thread will need to be done with a cutter and
not an insert.
ERS

Hey Peter,

Does the mill have a threading option? Or how did you get the same
entry point on each of 8 passes? If you were using a taper tap, why
did it take so many passes?

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXXXXXX

On Sat, 31 Dec 2005 02:48:01 -0500, "Peter Kiproff"
wrote:

HI ALL

I need to make a dozen ball nut adapters, requiring a 15/16 - 16 tpi
internal thread

first thought was a single point, small diameter rotating tool. Graduated to
what was on hand

a 3/8 - 16 tpi tap, then I ground off all the other flutes except for one
untouched row.

mounted this in a mill, did a circle command & included Z - .0625

on each pass the entire hole was threaded @ once as Z moved down 1 pitch.

8 passes later the part mates great!

I always wanted to try this & now I'm enthusiastic.

My question is, What other tooling besides the correct tap & what seems
expensive Thread milling tool

or methods do you use, I could have done this on the lathe semi manually but
this would take more time as

I could not just let it run & walk away. ;-)

I also want to do 1/4 - 20's & 3/8 -16's but I guess that's really pushing
it.

Is there a recommended way?

Peter

Peter Kiproff wrote:

HI ALL

I need to make a dozen ball nut adapters, requiring a 15/16 - 16 tpi
internal thread

first thought was a single point, small diameter rotating tool. Graduated to
what was on hand

a 3/8 - 16 tpi tap, then I ground off all the other flutes except for one
untouched row.

mounted this in a mill, did a circle command & included Z - .0625

on each pass the entire hole was threaded @ once as Z moved down 1 pitch.

8 passes later the part mates great!

I always wanted to try this & now I'm enthusiastic.

My question is, What other tooling besides the correct tap & what seems
expensive Thread milling tool

or methods do you use, I could have done this on the lathe semi manually but
this would take more time as

I could not just let it run & walk away. ;-)

I also want to do 1/4 - 20's & 3/8 -16's but I guess that's really pushing
it.

Is there a recommended way?

Peter




Buy a _single point_ threadmill. One size will do several diameters and
pitches. It just takes longer than a full profile threadmill.

Fred

HI BRIAN

I used the G02 arc command and had it start & finish each pass on the 6
o'clock position
I could have done it in less passes, but since this was my first try I
wanted to trial fit as I went.

One thing that also came out was the thread is always starting @ the same
place, also the part I'm
mating to... I can set it so the part, a ball nut, always has the return
tubes pointing the same way.

Peter

"Brian Lawson" wrote in message
...
Hey Peter,

Does the mill have a threading option? Or how did you get the same
entry point on each of 8 passes? If you were using a taper tap, why
did it take so many passes?

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXXXXXX

On Sat, 31 Dec 2005 02:48:01 -0500, "Peter Kiproff"
wrote:

HI ALL

I need to make a dozen ball nut adapters, requiring a 15/16 - 16 tpi
internal thread

first thought was a single point, small diameter rotating tool. Graduated
to
what was on hand

a 3/8 - 16 tpi tap, then I ground off all the other flutes except for one
untouched row.

mounted this in a mill, did a circle command & included Z - .0625

on each pass the entire hole was threaded @ once as Z moved down 1 pitch.

8 passes later the part mates great!

I always wanted to try this & now I'm enthusiastic.

My question is, What other tooling besides the correct tap & what seems
expensive Thread milling tool

or methods do you use, I could have done this on the lathe semi manually
but
this would take more time as

I could not just let it run & walk away. ;-)

I also want to do 1/4 - 20's & 3/8 -16's but I guess that's really
pushing
it.

Is there a recommended way?

Peter

On Sun, 1 Jan 2006 02:25:30 -0500, "Peter Kiproff"
wrote:

HI BRIAN

I used the G02 arc command and had it start & finish each pass on the 6
o'clock position
I could have done it in less passes, but since this was my first try I
wanted to trial fit as I went.

One thing that also came out was the thread is always starting @ the same
place, also the part I'm
mating to... I can set it so the part, a ball nut, always has the return
tubes pointing the same way.

Peter

Hey Peter,

Good trick. Thank you.

Brian