[DougC]

Is both the male & female threads tapered, or just the male? I cannot
see from the examples I have on hand if it is both or not. Wikipedia
seems to indicate both are.

I could cut external tapered threads on the lathe (I think,,, never done
that yet) but don't know how I'd do internal ones since the lathe has no
taper attachment.

Relating to the aluminum radiator building--I have to relocate the
coolant temperature sensor, which uses a 3/8"-18 pipe thread. It screws
into the top of the thermostat housing.... so what I need is a nipple
for 1/2" ID hose that screws into the thermostat housing, and then I
need to make a "T" fitting that the temp sensor will screw into, along
with two 1/2" hose nipples.

I had assumed there would be taps & dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps & dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal & external.

[DougC]

On 2/9/2012 12:06 AM, DougC wrote:
........
I had assumed there would be taps & dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps & dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal & external.


Well really, it looks like it is easiest & fastest to just order a
T-fitting and nipples already made off of McMaster,,, but I am still
curious.

The methods that I have seen for cutting tapers (or tapered threads) on
a normal lathe is to offset the tailstock, and spin the part between
centers... but you can't do that if you're cutting internal threads.

So that is why I am wondering how to cut internal tapered threads on a
manual lathe without a taper attachment, or if it can even be done.

[Tim Wescott]

On Thu, 09 Feb 2012 00:18:21 -0600, DougC wrote:

On 2/9/2012 12:06 AM, DougC wrote:
........
I had assumed there would be taps & dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps & dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal & external.


Well really, it looks like it is easiest & fastest to just order a
T-fitting and nipples already made off of McMaster,,, but I am still
curious.

The methods that I have seen for cutting tapers (or tapered threads) on
a normal lathe is to offset the tailstock, and spin the part between
centers... but you can't do that if you're cutting internal threads.

So that is why I am wondering how to cut internal tapered threads on a
manual lathe without a taper attachment, or if it can even be done.

You can get taps.



--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

[PrecisionmachinisT]

"Tim Wescott" wrote in message
...
On Thu, 09 Feb 2012 00:18:21 -0600, DougC wrote:

On 2/9/2012 12:06 AM, DougC wrote:
........
I had assumed there would be taps & dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps & dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal & external.


Well really, it looks like it is easiest & fastest to just order a
T-fitting and nipples already made off of McMaster,,, but I am still
curious.

The methods that I have seen for cutting tapers (or tapered threads) on
a normal lathe is to offset the tailstock, and spin the part between
centers... but you can't do that if you're cutting internal threads.

So that is why I am wondering how to cut internal tapered threads on a
manual lathe without a taper attachment, or if it can even be done.

You can get taps.


Hand grind a few flutes onto an old pipe plug and use it as a ****ing tap
for christ sakes.

[DougC]

On 2/9/2012 1:39 AM, PrecisionmachinisT wrote:
"Tim wrote in message
...
On Thu, 09 Feb 2012 00:18:21 -0600, DougC wrote:

On 2/9/2012 12:06 AM, DougC wrote:
........
I had assumed there would be taps& dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps& dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal& external.


Well really, it looks like it is easiest& fastest to just order a
T-fitting and nipples already made off of McMaster,,, but I am still
curious.

The methods that I have seen for cutting tapers (or tapered threads) on
a normal lathe is to offset the tailstock, and spin the part between
centers... but you can't do that if you're cutting internal threads.

So that is why I am wondering how to cut internal tapered threads on a
manual lathe without a taper attachment, or if it can even be done.

You can get taps.


Hand grind a few flutes onto an old pipe plug and use it as a ****ing tap
for christ sakes.



What old pipe plug? The local hardware stores only carry blumbing
fittings in plastic, brass, cast iron and some (?) kind of zinc-plated
steel.

I'd have had to order something anyway.... It aint an emergency though.

[Pete Keillor]

On Thu, 09 Feb 2012 03:53:21 -0600, DougC
wrote:

On 2/9/2012 1:39 AM, PrecisionmachinisT wrote:
"Tim wrote in message
...
On Thu, 09 Feb 2012 00:18:21 -0600, DougC wrote:

On 2/9/2012 12:06 AM, DougC wrote:
........
I had assumed there would be taps& dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps& dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal& external.


Well really, it looks like it is easiest& fastest to just order a
T-fitting and nipples already made off of McMaster,,, but I am still
curious.

The methods that I have seen for cutting tapers (or tapered threads) on
a normal lathe is to offset the tailstock, and spin the part between
centers... but you can't do that if you're cutting internal threads.

So that is why I am wondering how to cut internal tapered threads on a
manual lathe without a taper attachment, or if it can even be done.

You can get taps.


Hand grind a few flutes onto an old pipe plug and use it as a ****ing tap
for christ sakes.



What old pipe plug? The local hardware stores only carry blumbing
fittings in plastic, brass, cast iron and some (?) kind of zinc-plated
steel.

I'd have had to order something anyway.... It aint an emergency though.

I've got tapered pipe taps for a few smaller sizes, 1/4, 1/8. You can
buy about any size you'd want, but they get expensive. Try
http://www.mcmaster.com/#pipe-taps/=g67ub6

Pete Keillor

[Karl Townsend]

....
Hand grind a few flutes onto an old pipe plug and use it as a ****ing tap
for christ sakes.



What old pipe plug? The local hardware stores only carry blumbing
fittings in plastic, brass, cast iron and some (?) kind of zinc-plated
steel.

I'd have had to order something anyway.... It aint an emergency though.

Don't think the metal in pipe plugs is good enough. You *could* turn
some tool steel between centers and then cut flutes and harden to make
a tap. But, I'd just shop eBay for the real thing.

Karl

[Ignoramus13761]

I have a ****load of pipe taps up to 5 inches NPT.

i
On 2012-02-09, PrecisionmachinisT wrote:

"Tim Wescott" wrote in message
...
On Thu, 09 Feb 2012 00:18:21 -0600, DougC wrote:

On 2/9/2012 12:06 AM, DougC wrote:
........
I had assumed there would be taps & dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps & dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal & external.


Well really, it looks like it is easiest & fastest to just order a
T-fitting and nipples already made off of McMaster,,, but I am still
curious.

The methods that I have seen for cutting tapers (or tapered threads) on
a normal lathe is to offset the tailstock, and spin the part between
centers... but you can't do that if you're cutting internal threads.

So that is why I am wondering how to cut internal tapered threads on a
manual lathe without a taper attachment, or if it can even be done.

You can get taps.


Hand grind a few flutes onto an old pipe plug and use it as a ****ing tap
for christ sakes.

[PrecisionmachinisT]

"Karl Townsend" wrote in message
...
...
Hand grind a few flutes onto an old pipe plug and use it as a ****ing
tap
for christ sakes.



What old pipe plug? The local hardware stores only carry blumbing
fittings in plastic, brass, cast iron and some (?) kind of zinc-plated
steel.

I'd have had to order something anyway.... It aint an emergency though.

Don't think the metal in pipe plugs is good enough. You *could* turn
some tool steel between centers and then cut flutes and harden to make
a tap. But, I'd just shop eBay for the real thing.


I thought he had said he was wanting to tap aluminum but looking back I
guess that's not really clear.

[Jim Wilkins[_2_]]

"DougC" wrote in message
...
...
I had assumed there would be taps & dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the dies
are "long" because they are for threading pipe.... Is there any 'normal'
taps & dies sold for this, at a /relatively/ cheap price? I just need the
one 3/8"-18 size, internal & external.


Where are you, Beverly Hills?

Around here every surviving (= well-run) small hardware store carries or can
get them:
http://www.truevalue.com/product/38-...-Tap/20860.uts
http://www.acehardware.com/product/i...ductId=1290739

jsw

[Glenn Lyford]

On Feb 9, 7:28*am, Karl Townsend
wrote:
Don't think the metal in pipe plugs is good enough.

I found grinding flutes in a steel plug was good enough for chasing
crud out of brass threads for replacing a showerhead arm. It meant I
didn't have to rip open the wall, but I don't know how well it would
have cut new threads in aluminum. I've found pipe taps at local
secondhand tool stores but the ones I had on hand bottomed out before
the threads engaged, so I improvised.

If all he needs is fittings (tees and pipe nipples) I guess I'm
confused on why he needs to make them rather than buy them in brass, I
can find 3/8 sizes even at the big box stores, they might just be
across the aisle from the large fittings in little bags/bins. Got to
be cheaper than a tap.

--Glenn Lyford

[Stanley Schaefer]

On Feb 8, 11:06*pm, DougC wrote:
Is both the male & female threads tapered, or just the male? I cannot
see from the examples I have on hand if it is both or not. Wikipedia
seems to indicate both are.

I could cut external tapered threads on the lathe (I think,,, never done
that yet) but don't know how I'd do internal ones since the lathe has no
taper attachment.

Relating to the aluminum radiator building--I have to relocate the
coolant temperature sensor, which uses a 3/8"-18 pipe thread. It screws
into the top of the thermostat housing.... so what I need is a nipple
for 1/2" ID hose that screws into the thermostat housing, and then I
need to make a "T" fitting that the temp sensor will screw into, along
with two 1/2" hose nipples.

I had assumed there would be taps & dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps & dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal & external.

Both are tapered, at least the ones I have on hand are. Make sure
what you have, there's a straight series as well. A Real Hardware
store should have pipe taps at least up to 1/2", a big box home
improvement joint, probably not. I've seen button dies for small pipe
sizes, The larger ones tend to have separate chasers, just because
of the thread length. The local hardwares have all sorts of hose
barbs in whatever pipe sizes needed, in brass and for a price, but
they ARE available. If you're in the boonies, you may have a time
locating parts. NAPA has some hose fittings as well, you just have to
decide what exactly you need.

Stan

[Jim Stewart]

PrecisionmachinisT wrote:

Hand grind a few flutes onto an old pipe plug and use it as a ****ing tap
for christ sakes.

It's a metalworking question at least. Why all
the anger?

[Jim Wilkins[_2_]]

"Stanley Schaefer" wrote

Both are tapered, at least the ones I have on hand are. Make sure
what you have, there's a straight series as well. ...
Stan

Outside of hydraulics I've seen straight pipe-sized threads only on screw-in
water heater elements and shower head adapters.

jsw

[whit3rd]

Yes, of course the usual pipe taps are tapered.
You will want to use Al parts, because Cu is
a major corrosion issue -- maybe galvanized
is OK, though.

If you bore and straight-thread on the lathe, the
final machining is just a quick touchup with the
tap. Just look for NPT taps, stands for
National Pipe Thread.

[whit3rd]

Just look for NPT taps, stands for National
Pipe Thread.
Just to be clear, pipe thread 1/8 is suitable for
pipe of 1/8" internal diameter, about 3/8" external size.

[Bob Engelhardt]

whit3rd wrote:
.... Just look for NPT taps, stands for
National Pipe Thread.

Actually, it stands for National Pipe Tapered. And NPS for National
Pipe Straight.

Bob

[DougC]

On 2/9/2012 12:52 PM, whit3rd wrote:
Yes, of course the usual pipe taps are tapered.
You will want to use Al parts, because Cu is
a major corrosion issue -- maybe galvanized
is OK, though.

If you bore and straight-thread on the lathe, the
final machining is just a quick touchup with the
tap. Just look for NPT taps, stands for
National Pipe Thread.

Well I did end up just ordering some aluminum nipples and a "T" fitting
from McMaster. The remaining question was how to cut internal tapered
threads on a lathe that didn't have a taper attachment.

I saw the NPT taps at Enco, $28 for a 3/8"... Enco was offline at that
moment...

I noticed that the temperature sensor was brass, and it screwed into an
aluminum thermostat housing--and there appears to be some brown
corrosion in the aluminum thermostat housing threads. I couldn't tell
from briefly looking if that was the aluminum corroding or not. I had
not seen this connection leak before, so the rust I saw may have been
free-floating rust from the iron engine block (this is why I built the
magnetic trap in the new radiator tanks).


I know that the local hardware store sells brass and steel/zinc plumbing
fixtures, but I wanted at least one aluminum nipple to screw into the
remaining thermostat housing threads. ...As for the remaining
components, I got them in aluminum also since I had to mail-order the
one aluminum nipple from McMaster, and the thermostat sensor can be
grounded directly off its own body so there will be no current flowing
through the brass/aluminum there connection at all. This may not
eliminate corrosion in the sensor threads, but should drastically
eliminate it.

[Robert Nichols]

On 02/09/2012 12:13 PM, Jim Wilkins wrote:
"Stanley wrote

Both are tapered, at least the ones I have on hand are. Make sure
what you have, there's a straight series as well. ...
Stan

Outside of hydraulics I've seen straight pipe-sized threads only on screw-in
water heater elements and shower head adapters.

Electrical conduit & fittings and lamp parts are NPS.

--
Bob Nichols AT comcast.net I am "RNichols42"

[Dennis]

"Jim Stewart" wrote in message
...
PrecisionmachinisT wrote:

Hand grind a few flutes onto an old pipe plug and use it as a ****ing tap
for christ sakes.

It's a metalworking question at least. Why all
the anger?

Its PmT, he must be hormonal again.

[Phil Kangas[_4_]]

"Dennis" wrote in
message
. au...

"Jim Stewart" wrote in
message ...
PrecisionmachinisT wrote:

Hand grind a few flutes onto an old pipe plug
and use it as a ****ing tap
for christ sakes.

It's a metalworking question at least. Why all
the anger?

Its PmT, he must be hormonal again.


Nah.. I think he saw the job as tapping a hole in
a thin walled aluminum
housing and the OP didn't want to spend money on a
tap. Since only
a few threads are involved it would not take much
of a tap to do it
so in frustration he made that statement. I gotta
say, I've done that
myself years ago when it had to be done right now
with what was on
hand. It is cheap quick and dirty but it works,
fit form function ya know..
IOW, put down your mug and just ****ing do it
already, eih? ;)}

[PrecisionmachinisT]

"Jim Stewart" wrote in message ...
PrecisionmachinisT wrote:

Hand grind a few flutes onto an old pipe plug and use it as a ****ing tap
for christ sakes.

It's a metalworking question at least. Why all
the anger?

Anger...

LOL

[PrecisionmachinisT]

"DougC" wrote in message ...

The remaining question was how to cut internal tapered threads on a lathe that didn't have a taper attachment.

Basically, you don't

[Ed Huntress]

On Thu, 9 Feb 2012 18:56:47 -0800, "PrecisionmachinisT"
wrote:


"DougC" wrote in message ...

The remaining question was how to cut internal tapered threads on a lathe that didn't have a taper attachment.

Basically, you don't

Well, you can set the tailstock over to cut *external* threads on an
emergency pipe tap. But it won't work if the workpiece is too long.
You're limited by how far you can set your tailstock over.

--
Ed Huntress

[Ed Huntress]

On Thu, 09 Feb 2012 22:09:40 -0500, Ed Huntress
wrote:

On Thu, 9 Feb 2012 18:56:47 -0800, "PrecisionmachinisT"
wrote:


"DougC" wrote in message ...

The remaining question was how to cut internal tapered threads on a lathe that didn't have a taper attachment.

Basically, you don't

Well, you can set the tailstock over to cut *external* threads on an
emergency pipe tap. But it won't work if the workpiece is too long.
You're limited by how far you can set your tailstock over.

Wait a minute. If you're cutting internal tapered threads, you can set
that up with the compound and use the compound feed. Right?

--
Ed Huntress

[DoN. Nichols[_2_]]

On 2012-02-09, DougC wrote:
On 2/9/2012 12:06 AM, DougC wrote:
........
I had assumed there would be taps & dies for this. I have found many
sources for cheap dies (pipe threading kits) but no taps yet, and the
dies are "long" because they are for threading pipe.... Is there any
'normal' taps & dies sold for this, at a /relatively/ cheap price? I
just need the one 3/8"-18 size, internal & external.


Well really, it looks like it is easiest & fastest to just order a
T-fitting and nipples already made off of McMaster,,, but I am still
curious.

The methods that I have seen for cutting tapers (or tapered threads) on
a normal lathe is to offset the tailstock, and spin the part between
centers... but you can't do that if you're cutting internal threads.

Yes, you can't.

And doing an external tapered thread without a taper attachment
can also be tricky, depending on the length of the pipe to receive the
tapered thread. If it is too long, you can't mount it between centers.
And you may not be able to get enough offset in the tailstock to get the
right taper, either. (BTW, turning between balls might be easier than
between centers for pipe. Make up centers which end in hardened balls.

So that is why I am wondering how to cut internal tapered threads on a
manual lathe without a taper attachment, or if it can even be done.

Yes -- with a tap made for the thread in question. They are
made and sold. I have some of various (small) sizes.

There are also matching dies.

And there are chasers for Geometric die heads to cut tapered
threads as well as straight ones, if you happen to have a bed turret for
the lathe.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

[azotic[_4_]]

"Ed Huntress" wrote in message
...
On Thu, 09 Feb 2012 22:09:40 -0500, Ed Huntress
wrote:

On Thu, 9 Feb 2012 18:56:47 -0800, "PrecisionmachinisT"
wrote:


"DougC" wrote in message
...

The remaining question was how to cut internal tapered threads on a
lathe that didn't have a taper attachment.

Basically, you don't

Well, you can set the tailstock over to cut *external* threads on an
emergency pipe tap. But it won't work if the workpiece is too long.
You're limited by how far you can set your tailstock over.

Wait a minute. If you're cutting internal tapered threads, you can set
that up with the compound and use the compound feed. Right?

--
Ed Huntress

Depends on what type of crashbox you have.

Best Regards
Tom.
--
http://fija.org/

[Ned Simmons]

On 10 Feb 2012 03:31:31 GMT, "DoN. Nichols"
wrote:



And there are chasers for Geometric die heads to cut tapered
threads as well as straight ones, if you happen to have a bed turret for
the lathe.

Enjoy,
DoN.

A turret may be convenient, but I mount the Geometric head in a boring
bar holder on the toolpost.

--
Ned Simmons

[Ned Simmons]

On Thu, 09 Feb 2012 19:28:51 -0600, Robert Nichols
wrote:

On 02/09/2012 12:13 PM, Jim Wilkins wrote:
"Stanley wrote

Both are tapered, at least the ones I have on hand are. Make sure
what you have, there's a straight series as well. ...
Stan

Outside of hydraulics I've seen straight pipe-sized threads only on screw-in
water heater elements and shower head adapters.

Electrical conduit & fittings and lamp parts are NPS.

Conduit uses a tapered male thread; female threads on conduit fittings
are generally NPS.

--
Ned Simmons

[Jim Wilkins[_2_]]

"Ned Simmons" wrote in message
...
On Thu, 09 Feb 2012 19:28:51 -0600, Robert Nichols
wrote:

On 02/09/2012 12:13 PM, Jim Wilkins wrote:
"Stanley wrote

Both are tapered, at least the ones I have on hand are. Make sure
what you have, there's a straight series as well. ...
Stan

Outside of hydraulics I've seen straight pipe-sized threads only on
screw-in
water heater elements and shower head adapters.

Electrical conduit & fittings and lamp parts are NPS.

Conduit uses a tapered male thread; female threads on conduit fittings
are generally NPS.
Ned Simmons

I'm fairly sure I've seen both straight and tapered, depending on if it was
indoor or liquid-tight, cast metal or plastic box. The plastic imitation
Sealtite that Lowe's sells uses straight male threads and an O ring. I don't
have other samples handy to check.

I should have qualified my statement with "plumbing" though he's not likely
to use an electrical conduit fitting on the radiator.

jsw

[Ned Simmons]

On Fri, 10 Feb 2012 11:12:29 -0500, "Jim Wilkins"
wrote:


"Ned Simmons" wrote in message
.. .
On Thu, 09 Feb 2012 19:28:51 -0600, Robert Nichols
wrote:

On 02/09/2012 12:13 PM, Jim Wilkins wrote:
"Stanley wrote

Both are tapered, at least the ones I have on hand are. Make sure
what you have, there's a straight series as well. ...
Stan

Outside of hydraulics I've seen straight pipe-sized threads only on
screw-in
water heater elements and shower head adapters.

Electrical conduit & fittings and lamp parts are NPS.

Conduit uses a tapered male thread; female threads on conduit fittings
are generally NPS.
Ned Simmons

I'm fairly sure I've seen both straight and tapered, depending on if it was
indoor or liquid-tight, cast metal or plastic box. The plastic imitation
Sealtite that Lowe's sells uses straight male threads and an O ring. I don't
have other samples handy to check.

I should have qualified my statement with "plumbing" though he's not likely
to use an electrical conduit fitting on the radiator.

jsw


I don't doubt that some fittings, especially those for products other
than rigid conduit, have straight male threads. But tapered threads
are specified for the ends of conduit.

From Wheatland’s website:

Wheatland’s Galvanized steel Rigid Metal Conduit
(RMC) is manufactured in accordance with the latest
specifications and standards of ANSI
® C80.1, UL-6,
and federal specification WW-C-581. The pitch of
RMC threads conforms to the American National
Standard for Pipe Threads, General Purpose (Inch),
ANSI/ASME B1.20.1. The taper of threads is 3/4 inch
per foot (1 in 16).

And the NEC specifies tapered threads for field threading:

344.28 Reaming and Threading. All cut ends shall be
reamed or otherwise finished to remove rough edges.
Where conduit is threaded in the field, a standard cutting
die with a 1 in16 taper (3/4-in. taper per foot) shall be used.
FPN: See ANSI/ASME B.1.20.1-1983, Standard for Pipe
Threads, General Purpose (Inch).

--
Ned Simmons

[Bob Engelhardt]

Ed Huntress wrote:
Wait a minute. If you're cutting internal tapered threads, you can set
that up with the compound and use the compound feed. Right?


If you can crank the compound wheel at just the right speed to get the
tpi you need. Give that guy a dope slap ... no, wait - it's Ed. Even
he can goof up. VBG

Bob

[Ed Huntress]

On Fri, 10 Feb 2012 12:34:04 -0500, Bob Engelhardt
wrote:

Ed Huntress wrote:
Wait a minute. If you're cutting internal tapered threads, you can set
that up with the compound and use the compound feed. Right?


If you can crank the compound wheel at just the right speed to get the
tpi you need. Give that guy a dope slap ... no, wait - it's Ed. Even
he can goof up. VBG

Bob

Jesus. Geometry must be the third thing to go. d8-)

--
Ed Huntress

[Wild_Bill]

I'm just too lazy to look it up, but if you have almost any smaller diameter
tap with the same thread pitch, it can be used to cut a tapered thread.

The tap is mounted in the toolpost with the cuting edges properly oriented,
then bump the toolpost so the tap's free end moves inward slightly.

A few trial/error attempts on scrap practice pieces should get the tap
angled just enough to match the pipe thread taper.

I'd suggest a hand crank on the spindle After pulling the lathe's power cord
plug from the receptacle, and using a generous amount of quality cutting
lubricant.

Set the feed rate to match the thread pitch, and use the off-axis tap as a
multi-point boring bar.. feed in with the hand crank for a light cut, back
the cross feed in, back up the carriage, adjust for another light cut,
engage and turn crank.. repeat until diameter and depth (thread count) are
achieved.

It's not as easy to get answers to some types of metalworking questions when
so many talented and bright metalworkers have stopped participating in RCM
as a result of disgust over the rampant, senseless off topic bull****.

Yep, RCM is where I learned such tricks, years ago.

--
WB
..........


"DougC" wrote in message
...

The remaining question was how to cut internal tapered threads on a lathe
that didn't have a taper attachment.

I saw the NPT taps at Enco, $28 for a 3/8"... Enco was offline at that
moment...

I noticed that the temperature sensor was brass, and it screwed into an
aluminum thermostat housing--and there appears to be some brown corrosion
in the aluminum thermostat housing threads. I couldn't tell from briefly
looking if that was the aluminum corroding or not. I had not seen this
connection leak before, so the rust I saw may have been free-floating rust
from the iron engine block (this is why I built the magnetic trap in the
new radiator tanks).


I know that the local hardware store sells brass and steel/zinc plumbing
fixtures, but I wanted at least one aluminum nipple to screw into the
remaining thermostat housing threads. ...As for the remaining components,
I got them in aluminum also since I had to mail-order the one aluminum
nipple from McMaster, and the thermostat sensor can be grounded directly
off its own body so there will be no current flowing through the
brass/aluminum there connection at all. This may not eliminate corrosion
in the sensor threads, but should drastically eliminate it.

[Jim Wilkins[_2_]]

"Ed Huntress" wrote in message
...
On Fri, 10 Feb 2012 12:34:04 -0500, Bob Engelhardt
wrote:

Ed Huntress wrote:
Wait a minute. If you're cutting internal tapered threads, you can set
that up with the compound and use the compound feed. Right?


If you can crank the compound wheel at just the right speed to get the
tpi you need. Give that guy a dope slap ... no, wait - it's Ed. Even
he can goof up. VBG

Bob

Jesus. Geometry must be the third thing to go. d8-)
Ed Huntress

It's easy. Just hook that weedwhacker driveshaft from the end of the
leadscrew to the compound handle.

jsw

[Ed Huntress]

On Fri, 10 Feb 2012 17:17:51 -0500, "Jim Wilkins"
wrote:


"Ed Huntress" wrote in message
.. .
On Fri, 10 Feb 2012 12:34:04 -0500, Bob Engelhardt
wrote:

Ed Huntress wrote:
Wait a minute. If you're cutting internal tapered threads, you can set
that up with the compound and use the compound feed. Right?


If you can crank the compound wheel at just the right speed to get the
tpi you need. Give that guy a dope slap ... no, wait - it's Ed. Even
he can goof up. VBG

Bob

Jesus. Geometry must be the third thing to go. d8-)
Ed Huntress

It's easy. Just hook that weedwhacker driveshaft from the end of the
leadscrew to the compound handle.

I was thinking about a gear train and sliding spline...no, huh? g

--
Ed Huntress



jsw

[Jim Wilkins[_2_]]

"Ed Huntress" wrote in message
...
On Fri, 10 Feb 2012 17:17:51 -0500, "Jim Wilkins"
wrote:

It's easy. Just hook that weedwhacker driveshaft from the end of the
leadscrew to the compound handle.

I was thinking about a gear train and sliding spline...no, huh? g
Ed Huntress

A countershaft hung from the ceiling to turn the pulley on the compound
handle, like the old Pratt & Whitney high-speed grinder drives.

The bigger the better, for a retro visual effect to match your Heavy 10. Can
you still find round leather sewing machine belting in NY?

jsw

[Ed Huntress]

On Fri, 10 Feb 2012 17:55:18 -0500, "Jim Wilkins"
wrote:


"Ed Huntress" wrote in message
.. .
On Fri, 10 Feb 2012 17:17:51 -0500, "Jim Wilkins"
wrote:

It's easy. Just hook that weedwhacker driveshaft from the end of the
leadscrew to the compound handle.

I was thinking about a gear train and sliding spline...no, huh? g
Ed Huntress

A countershaft hung from the ceiling to turn the pulley on the compound
handle, like the old Pratt & Whitney high-speed grinder drives.

The bigger the better, for a retro visual effect to match your Heavy 10. Can
you still find round leather sewing machine belting in NY?

jsw

I haven't looked for round leather belting, but I can come up with
plenty of flyball governors and a canary that will sing when some food
drops down in his cage, which excites a cat, which jumps onto a ledge
connected to a bellcrank, which trips a pinball flapper that pushes a
big marble onto a chute....

--
Ed Huntress

[DoN. Nichols[_2_]]

On 2012-02-10, Ed Huntress wrote:
On Thu, 09 Feb 2012 22:09:40 -0500, Ed Huntress
wrote:

On Thu, 9 Feb 2012 18:56:47 -0800, "PrecisionmachinisT"
wrote:


"DougC" wrote in message ...

The remaining question was how to cut internal tapered threads on a lathe that didn't have
a taper attachment.

Basically, you don't

Well, you can set the tailstock over to cut *external* threads on an

Wait a minute. If you're cutting internal tapered threads, you can set
that up with the compound and use the compound feed. Right?

Do you have a compound feed geared to the spindle? You could
turn a short internal smooth taper, but without the gearing, threading
is sort of out of the question. :-) I've never seen one so equipped.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

[DoN. Nichols[_2_]]

On 2012-02-10, Ned Simmons wrote:
On 10 Feb 2012 03:31:31 GMT, "DoN. Nichols"
wrote:



And there are chasers for Geometric die heads to cut tapered
threads as well as straight ones, if you happen to have a bed turret for
the lathe.

[ ... ]

A turret may be convenient, but I mount the Geometric head in a boring
bar holder on the toolpost.

I've suggested that as a possibility in the past, but never
tried it myself, since I *have* the bed turret. :-) Mostly, it requires
some tricky centering to get it right.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---