Last week, I changed the undersized, crappy radiator in my kitchen for a bigger one that heats the room much better.? This involved undoing big threaded components that may not have been touched in half a century.
A tool that to some extent made the job possible was a 24" Crescent wrench I bought from Harbor Freight. It cost $33, which I thought was very reasonable considering the size. Here's a picture of my newly installed and painted radiator with the giant wrench on top of it.?
It may have been possible to get this plumbing apart with a small wrench and a cheater bar, but it wouldn't have been EASY, which it was with this wrench. (Also, taking heating equipment apart in the wintertime is a bit risky because if you screw up, the house may be cold for a long time).? I can't say any of us will ever find something on a minilathe that needs?a wrench this big, but I'll find other occasions to use it, and I bet you would too.
Mike Taglieri?
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Re: Threading and Compound
The lazy way is to use a thread restoring file to refine the profile & improve the surface finish.
?<??>
Roy
|
Re: Threading and Compound
GadgetBuilder 6:45am? ?
In the book "Screwcutting in the Lathe" Martin Cleeve presents three methods of advancing the tool when threading and discusses the issues with each method. This is a great book for anyone just learning how to thread on the lathe, covering most all aspects of threading
Do you have a photo you can post of three methods? Dave?
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Re: Threading and Compound
In the book "Screwcutting in the Lathe" Martin Cleeve presents three methods of advancing the tool when threading and discusses the issues with each method.? This is a great book for anyone just learning how to thread on the lathe, covering most all aspects of threading.
The issue with the methods shown in the Southbend book is that standard threads have a flat at the bottom of the thread which isn't shown in their diagrams (and tools with a sharp point would fail very quickly).? In practice, the width of this flat depends on the pitch of the thread being cut so, using the methods shown, the tool would need to be reground to have the correct width flat for each pitch to be cut.? This is fine for production when making identical parts but not so good in the home shop where we would prefer to use one threading tool for multiple pitches.
Cleeve suggests grinding the tool to have the flat for the finest thread to be cut. Set the compound parallel to the thread axis and each time a cut is added with the cross slide, advance the compound half that amount - this works almost like setting the compound over.? But when the tool is at depth one can advance the compound to produce the required thread flat which will also thin the thread to the standard dimensions as measured with the 3 wire method.? Cleve notes that brass cuts so easily that straight in using only the cross slide works fine.
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Re: Threading and Compound
I used 29.5° till 1976 and found straight free up the compound for settings.?
I could pickup threads fast and easy, lock carriage and find adjustment and quickly go back to threading.
Using reverse for blind threading by using carriage stop and compound for find adjustment.
I did read back 1990's why the 29° was used.?It was written around 1900.? ?
The low small lathes without back gears trying to thread corse threads the leather belt would slip. To fix this problem by using the compound to feed at 29°?
Sound like today's mini lathe.?
It when first using the world wide web. So was not into downloading yet.?
Today I would download put on on a few clouds and make hard copy.??
I was more taken by no back gear per WW1.
So there is a place for 29° or 29.5° now you can cut 4 TPI [6mm] on mini lathe.
Dave?
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Re: Threading and Compound
Actually both of my lathes have a compound.?
But I am in the long drawn out?process of automating both Z and X.
John Lindo is very enthusiastic about going straight in.
Some day I will eventually start doing threads and just thinking of the method I will use.
Ralph
On Sat, Mar 2, 2024 at 3:31?PM mike allen < animal@...> wrote:
Ralph is talking about a lathe without a compound .
animal
On 3/2/24 12:25 PM, Charles Kinzer
wrote:
The tool is advanced with the
compound.? The cross feed is used to extract the tool after a
pass.? And then the cross feed is returned to its same
position each time and the compound moved in a little.?
Sometimes, some people, make a very light finishing cut going
straight in.? But if you have everything set up properly, this
is not necessary.
One little benefit is that
the sine of 30 degrees is 0.5 so the increments of the
compound wheel will automatically refer to removal in terms of
radius instead of diameter (assuming the hand wheel is marked
for diameter removal in the first place.)? Yes, 29.5 isn't 30,
but it is so close that the error is typically negligible.
Charles E. "Chuck" Kinzer
On Saturday, March 2, 2024 at 11:37:23 AM PST, Ralph
Hulslander <rhulslander@...> wrote:
Is the tool advanced with the compound?or
the cross feed?
John Lindo was the
first that I know going straight? in. He is using
his RLS with automated Z and X.
He threw his compound?away.
Ralph
On Sat,
Mar 2, 2024 at 1:35?PM Charles Kinzer < ckinzer@...>
wrote:
This is a topic that has been
discussed repeatedly on this list.? I guess it
won't hurt to cover the same ground again.
In the hobby world, typically
making small threads, at low speeds, often in
friendly materials like brass or aluminum,
there may be little to no difference what
method is used.
In production, and with larger
threads, and harder materials like steel or
stainless steel, and at production speeds,
there is a significant difference. And the
difference is all about how the chip is
produced.? This is what the 29.5 (or 29)
degree angle is all about.? (Note:? You will
find some production work that does go
"straight in" however as there are times when
that is still possible.)
When you go straight in, you are
producing two equal size chips from the left
and right cutting edges.? The chip from the
left edge goes up and to the right.? The chip
from the right edge goes up and to the left.?
That means they collide in the air space above
nose of the tool.? This causes a tearing
effect and also puts more stress on the
cutting tool tip.? The result can be poor
surface finish, wasted power (time) dissipated
in the two chips mashing together, more heat,
and even a broken tool tip.? A poor surface
finish would be the most likely risk in a mini
lathe in my opinion.
The purpose of the angled
compound movement is to have almost all
cutting on the left edge.? By having the
compound at 29.5 (or 29) degrees there will be
a very slight skim cut on the right edge.?
This ensures a clean surface on that side of
the thread and also helps cause tool contact
for heat transfer on the right edge.? This
eliminates that chip collision problem.
Sometimes on this list I have
seen people say it makes a "stair step"
thread.? This technique, used properly, does
NOT do that.? If somebody is getting that
result, it is due to a simple geometry error
that can be one or all of these things:?
Compound not really at the correct angle (the
protractor markings on mini lathes are
notoriously inaccurate - measure with a
machinist's protractor), the tool bit is not
ground to the correct angle (double check with
a "thread gauge" a.k.a. "Fish Tail"), and/or
the tool bit is not perpendicular to the work
piece.
Charles E. "Chuck" Kinzer
On Saturday, March 2, 2024 at 09:58:47
AM PST, davesmith1800 < davesmith1@...>
wrote:
Here photo from How
to Run a Lathe
It shows two ways of threading.??
I have used both to me they work same.
Attachments:
|
Re: Threading and Compound
Ralph is talking about a lathe without a compound .
animal
On 3/2/24 12:25 PM, Charles Kinzer
wrote:
toggle quoted message
Show quoted text
The tool is advanced with the
compound.? The cross feed is used to extract the tool after a
pass.? And then the cross feed is returned to its same
position each time and the compound moved in a little.?
Sometimes, some people, make a very light finishing cut going
straight in.? But if you have everything set up properly, this
is not necessary.
One little benefit is that
the sine of 30 degrees is 0.5 so the increments of the
compound wheel will automatically refer to removal in terms of
radius instead of diameter (assuming the hand wheel is marked
for diameter removal in the first place.)? Yes, 29.5 isn't 30,
but it is so close that the error is typically negligible.
Charles E. "Chuck" Kinzer
On Saturday, March 2, 2024 at 11:37:23 AM PST, Ralph
Hulslander <rhulslander@...> wrote:
Is the tool advanced with the compound?or
the cross feed?
John Lindo was the
first that I know going straight? in. He is using
his RLS with automated Z and X.
He threw his compound?away.
Ralph
On Sat,
Mar 2, 2024 at 1:35?PM Charles Kinzer < ckinzer@...>
wrote:
This is a topic that has been
discussed repeatedly on this list.? I guess it
won't hurt to cover the same ground again.
In the hobby world, typically
making small threads, at low speeds, often in
friendly materials like brass or aluminum,
there may be little to no difference what
method is used.
In production, and with larger
threads, and harder materials like steel or
stainless steel, and at production speeds,
there is a significant difference. And the
difference is all about how the chip is
produced.? This is what the 29.5 (or 29)
degree angle is all about.? (Note:? You will
find some production work that does go
"straight in" however as there are times when
that is still possible.)
When you go straight in, you are
producing two equal size chips from the left
and right cutting edges.? The chip from the
left edge goes up and to the right.? The chip
from the right edge goes up and to the left.?
That means they collide in the air space above
nose of the tool.? This causes a tearing
effect and also puts more stress on the
cutting tool tip.? The result can be poor
surface finish, wasted power (time) dissipated
in the two chips mashing together, more heat,
and even a broken tool tip.? A poor surface
finish would be the most likely risk in a mini
lathe in my opinion.
The purpose of the angled
compound movement is to have almost all
cutting on the left edge.? By having the
compound at 29.5 (or 29) degrees there will be
a very slight skim cut on the right edge.?
This ensures a clean surface on that side of
the thread and also helps cause tool contact
for heat transfer on the right edge.? This
eliminates that chip collision problem.
Sometimes on this list I have
seen people say it makes a "stair step"
thread.? This technique, used properly, does
NOT do that.? If somebody is getting that
result, it is due to a simple geometry error
that can be one or all of these things:?
Compound not really at the correct angle (the
protractor markings on mini lathes are
notoriously inaccurate - measure with a
machinist's protractor), the tool bit is not
ground to the correct angle (double check with
a "thread gauge" a.k.a. "Fish Tail"), and/or
the tool bit is not perpendicular to the work
piece.
Charles E. "Chuck" Kinzer
On Saturday, March 2, 2024 at 09:58:47
AM PST, davesmith1800 < davesmith1@...>
wrote:
Here photo from How
to Run a Lathe
It shows two ways of threading.??
I have used both to me they work same.
Attachments:
|
Re: Threading and Compound
The tool is advanced with the compound.? The cross feed is used to extract the tool after a pass.? And then the cross feed is returned to its same position each time and the compound moved in a little.? Sometimes, some people, make a very light finishing cut going straight in.? But if you have everything set up properly, this is not necessary.
One little benefit is that the sine of 30 degrees is 0.5 so the increments of the compound wheel will automatically refer to removal in terms of radius instead of diameter (assuming the hand wheel is marked for diameter removal in the first place.)? Yes, 29.5 isn't 30, but it is so close that the error is typically negligible.
Charles E. "Chuck" Kinzer
On Saturday, March 2, 2024 at 11:37:23 AM PST, Ralph Hulslander <rhulslander@...> wrote:
Is the tool advanced with the compound?or the cross feed?
John Lindo was the first that I know going straight? in. He is using his RLS with automated Z and X. He threw his compound?away.
Ralph
On Sat, Mar 2, 2024 at 1:35?PM Charles Kinzer < ckinzer@...> wrote:
This is a topic that has been discussed repeatedly on this list.? I guess it won't hurt to cover the same ground again.
In the hobby world, typically making small threads, at low speeds, often in friendly materials like brass or aluminum, there may be little to no difference what method is used.
In production, and with larger threads, and harder materials like steel or stainless steel, and at production speeds, there is a significant difference. And the difference is all about how the chip is produced.? This is what the 29.5 (or 29) degree angle is all about.? (Note:? You will find some production work that does go "straight in" however as there are times when that is still possible.)
When you go straight in, you are producing two equal size chips from the left and right cutting edges.? The chip from the left edge goes up and to the right.? The chip from the right edge goes up and to the left.? That means they collide in the air space above nose of the tool.? This causes a tearing effect and also puts more stress on the cutting tool tip.? The result can be poor surface finish, wasted power (time) dissipated in the two chips mashing together, more heat, and even a broken tool tip.? A poor surface finish would be the most likely risk in a mini lathe in my opinion.
The purpose of the angled compound movement is to have almost all cutting on the left edge.? By having the compound at 29.5 (or 29) degrees there will be a very slight skim cut on the right edge.? This ensures a clean surface on that side of the thread and also helps cause tool contact for heat transfer on the right edge.? This eliminates that chip collision problem.
Sometimes on this list I have seen people say it makes a "stair step" thread.? This technique, used properly, does NOT do that.? If somebody is getting that result, it is due to a simple geometry error that can be one or all of these things:? Compound not really at the correct angle (the protractor markings on mini lathes are notoriously inaccurate - measure with a machinist's protractor), the tool bit is not ground to the correct angle (double check with a "thread gauge" a.k.a. "Fish Tail"), and/or the tool bit is not perpendicular to the work piece.
Charles E. "Chuck" Kinzer
On Saturday, March 2, 2024 at 09:58:47 AM PST, davesmith1800 < davesmith1@...> wrote:
Here photo from How to Run a LatheIt shows two ways of threading.?? I have used both to me they work same.
Attachments:
|
Re: Threading and Compound
Is the tool advanced with the compound?or the cross feed?
John Lindo was the first that I know going straight? in. He is using his RLS with automated Z and X. He threw his compound?away.
Ralph
On Sat, Mar 2, 2024 at 1:35?PM Charles Kinzer < ckinzer@...> wrote:
This is a topic that has been discussed repeatedly on this list.? I guess it won't hurt to cover the same ground again.
In the hobby world, typically making small threads, at low speeds, often in friendly materials like brass or aluminum, there may be little to no difference what method is used.
In production, and with larger threads, and harder materials like steel or stainless steel, and at production speeds, there is a significant difference. And the difference is all about how the chip is produced.? This is what the 29.5 (or 29) degree angle is all about.? (Note:? You will find some production work that does go "straight in" however as there are times when that is still possible.)
When you go straight in, you are producing two equal size chips from the left and right cutting edges.? The chip from the left edge goes up and to the right.? The chip from the right edge goes up and to the left.? That means they collide in the air space above nose of the tool.? This causes a tearing effect and also puts more stress on the cutting tool tip.? The result can be poor surface finish, wasted power (time) dissipated in the two chips mashing together, more heat, and even a broken tool tip.? A poor surface finish would be the most likely risk in a mini lathe in my opinion.
The purpose of the angled compound movement is to have almost all cutting on the left edge.? By having the compound at 29.5 (or 29) degrees there will be a very slight skim cut on the right edge.? This ensures a clean surface on that side of the thread and also helps cause tool contact for heat transfer on the right edge.? This eliminates that chip collision problem.
Sometimes on this list I have seen people say it makes a "stair step" thread.? This technique, used properly, does NOT do that.? If somebody is getting that result, it is due to a simple geometry error that can be one or all of these things:? Compound not really at the correct angle (the protractor markings on mini lathes are notoriously inaccurate - measure with a machinist's protractor), the tool bit is not ground to the correct angle (double check with a "thread gauge" a.k.a. "Fish Tail"), and/or the tool bit is not perpendicular to the work piece.
Charles E. "Chuck" Kinzer
On Saturday, March 2, 2024 at 09:58:47 AM PST, davesmith1800 < davesmith1@...> wrote:
Here photo from How to Run a LatheIt shows two ways of threading.?? I have used both to me they work same.
Attachments:
|
Re: Threading and Compound
This is a topic that has been discussed repeatedly on this list.? I guess it won't hurt to cover the same ground again.
In the hobby world, typically making small threads, at low speeds, often in friendly materials like brass or aluminum, there may be little to no difference what method is used.
In production, and with larger threads, and harder materials like steel or stainless steel, and at production speeds, there is a significant difference. And the difference is all about how the chip is produced.? This is what the 29.5 (or 29) degree angle is all about.? (Note:? You will find some production work that does go "straight in" however as there are times when that is still possible.)
When you go straight in, you are producing two equal size chips from the left and right cutting edges.? The chip from the left edge goes up and to the right.? The chip from the right edge goes up and to the left.? That means they collide in the air space above nose of the tool.? This causes a tearing effect and also puts more stress on the cutting tool tip.? The result can be poor surface finish, wasted power (time) dissipated in the two chips mashing together, more heat, and even a broken tool tip.? A poor surface finish would be the most likely risk in a mini lathe in my opinion.
The purpose of the angled compound movement is to have almost all cutting on the left edge.? By having the compound at 29.5 (or 29) degrees there will be a very slight skim cut on the right edge.? This ensures a clean surface on that side of the thread and also helps cause tool contact for heat transfer on the right edge.? This eliminates that chip collision problem.
Sometimes on this list I have seen people say it makes a "stair step" thread.? This technique, used properly, does NOT do that.? If somebody is getting that result, it is due to a simple geometry error that can be one or all of these things:? Compound not really at the correct angle (the protractor markings on mini lathes are notoriously inaccurate - measure with a machinist's protractor), the tool bit is not ground to the correct angle (double check with a "thread gauge" a.k.a. "Fish Tail"), and/or the tool bit is not perpendicular to the work piece.
Charles E. "Chuck" Kinzer
On Saturday, March 2, 2024 at 09:58:47 AM PST, davesmith1800 <davesmith1@...> wrote:
Here photo from How to Run a LatheIt shows two ways of threading.?? I have used both to me they work same. ![]() ![]()
Attachments:
|
Here photo from How to Run a LatheIt shows two ways of threading.?? I have used both to me they work same.  
|
I have a 4? ton arbor press upto ? broaching.?
Dave?
|
On Thu, Feb 29, 2024 at 12:28 PM, @ThomasKeefe wrote:
I have a 1 ton press from harbor freight to push the broach through. It can apply enough force to cut a keyway in steel, but it doesn't open quite far enough for the broaches I have used. Makes it difficult to get things started. How will you press the broach?
I also have a 1 ton press from harbor freight but I am going to use my 12 ton shop press with a guide on the ram to keep the broach aligned.
|
Faster than reading a book.
There is over size by 0.003" and tapper keyways. If you miss the size too.?
Dave?
|
Hello,Paul!
It is not rocket science. I would keep the keyway clearance at .0005” to .001”.
The closer the fit the less chance of wear.
|
I would look for 1940's maybe 1950's?
I have both books?
After that they become more difficult to under stand. In 1960's that start with more on product and by 1980's was going in CNC and writing was like school teach wrote the book.
?The 1940's was like machinist wrote book. Easy to find information fast.
Dave?
toggle quoted message
Show quoted text
mike allen
11:47am? ?
? ? ? ? If ya look for one to DL try to find a older one . The newer ones are aiming more & more to the CNC guys & stuff for us manual folks is disappearing . There's several online in PDF form that can be DL'd for free
animal
|
??? ??? If ya look for one to DL try to find a older one . The
newer ones are aiming more & more to the CNC guys & stuff
for us manual folks is disappearing . There's several online in
PDF form that can be DL'd for free
animal
On 2/29/24 8:21 AM, davesmith1800
wrote:
toggle quoted message
Show quoted text
paul mcclintic
7:33am? ?
On Thu, Feb 29, 2024 at 08:31 AM, OldToolmaker wrote:
"Machinerys HandBook” has all the data you need
I have one but it only tells me the keyway info, but
nothing that I found about clearance that should be used for the
width of the guide slot
I think looking for number.?
"Machinerys HandBook” could take days to find.
The book one is 1930s and 1940's? easy to find information.? I
have books from the 1941 to 1980's and have read the 1930s too.?
The number is max 0.000,5 oversize upto ?" keyways.
Most my work was 3/16" and 1/4" keyway few small keyway too.?
When I was single I purchased this had money too.?
Attachments:
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If you have the broach, simply measure it's width (not the same as keyway width) and cut a channel to give a close fit - maybe a few thousandths larger.?
I have a 1 ton press from harbor freight to push the broach through. It can apply enough force to cut a keyway in steel, but it doesn't open quite far enough for the broaches I have used. Makes it difficult to get things started. How will you press the broach?
You need to be careful that the broach does not tip forward when pressing, as that will distort the keyway. (Don't ask me how I know. :) )
Tom
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paul mcclintic
7:33am? ?
On Thu, Feb 29, 2024 at 08:31 AM, OldToolmaker wrote:
"Machinerys HandBook” has all the data you need
I have one but it only tells me the keyway info, but nothing that I found about clearance that should be used for the width of the guide slot
I think looking for number.? "Machinerys HandBook” could take days to find. The book one is 1930s and 1940's? easy to find information.? I have books from the 1941 to 1980's and have read the 1930s too.? The number is max 0.000,5 oversize upto ?" keyways. Most my work was 3/16" and 1/4" keyway few small keyway too.? When I was single I purchased this had money too.? 
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On Thu, Feb 29, 2024 at 08:31 AM, OldToolmaker wrote:
"Machinerys HandBook” has all the data you need
I have one but it only tells me the keyway info, but nothing that I found about clearance that should be used for the width of the guide slot.
|
davesmith1800
GadgetBuilder
OldToolmaker