This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
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Ignoramus13673 wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Single point bits are not the only type used in a lathe, and heavy
lathes often take heavy roughing cuts.

Check out the lowest RPM rating... Tells me maybe someone would turn a huge
diameter part in that machine as it can go down to 6 RPM. That could
require HP if the gearing were just "right" to need it.

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R


"Ignoramus13673" wrote in message
...
This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

--
Due to extreme spam originating from Google Groups, and their
inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

On Tue, 10 Jun 2008 14:43:26 -0500, Ignoramus13673
wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/
I can't speak about 20 HP but I have two lathes with 10 HP spindles
and have stalled them with heavy cuts. Using CNMG 432 inserts. Take
a look at the size of a CNMG 643 insert and you will get an idea of
the cuts that can be taken. Machinery's Handbook has HP calculators
that may help you understand the HP requirements.
Eric

Ignoramus13673 wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Perhaps you need to pick up a book or 2 on the theory of turning?
It's all about metal removal/time.
You'd really be gobsmacked if you come across a series 80 Monarch
lathe of the same swing. It will have a 60 hp motor.

Tom

On 2008-06-10, Tom wrote:
Ignoramus13673 wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Perhaps you need to pick up a book or 2 on the theory of turning?
It's all about metal removal/time.
You'd really be gobsmacked if you come across a series 80 Monarch
lathe of the same swing. It will have a 60 hp motor.

I am gobsmacked. Just found this page

http://netmachinery.net/cgi-bin/clas...uery=retrieval

weighs 10 tons

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
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On Tue, 10 Jun 2008 16:03:15 -0500, Ignoramus13673
wrote:

On 2008-06-10, Tom wrote:
Ignoramus13673 wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Perhaps you need to pick up a book or 2 on the theory of turning?
It's all about metal removal/time.
You'd really be gobsmacked if you come across a series 80 Monarch
lathe of the same swing. It will have a 60 hp motor.

I am gobsmacked. Just found this page

http://netmachinery.net/cgi-bin/clas...uery=retrieval

weighs 10 tons

Imagine what moving that thing would cost...
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Ignoramus13673 wrote:
On 2008-06-10, Tom wrote:
Ignoramus13673 wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any
lathe would need a 20 HP motor. I have hard times imagining how
even a fraction of that could be expended cutting metal with a
single point lathe bit.

Perhaps you need to pick up a book or 2 on the theory of turning?
It's all about metal removal/time.
You'd really be gobsmacked if you come across a series 80 Monarch
lathe of the same swing. It will have a 60 hp motor.

I am gobsmacked. Just found this page


http://netmachinery.net/cgi-bin/clas...=bmanuallathe&
website=&language=&session_key=&search_and_display _db_button=on&results_form
at=long&db_id=6695&query=retrieval

weighs 10 tons

Here's one down the road from me:
Teco-Westinghouse
"Lathes that handle up to a 350,000 lb. capacity. Lengths up to 43-feet
(center to center) and swing up to 180 inches are no problem."
http://www.tecowestinghouse.com/Service/repair.html
No pics

On Tue, 10 Jun 2008 14:43:26 -0500, Ignoramus13673
wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Material removal rate-- there are various tables, and, as always, it
depends on various factors, but by one rule of thumb 20HP would remove
about 30 in^3 per minute of steel or maybe 100 in^3 of aluminum.

If you want to turn something 12" in diameter down to 3" over an 8"
length, that's um.. around 850 in^3 if I did the math right, so it
would take almost half an hour for steel and 10 minutes for aluminum
if HP was the limiting factor.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

"Spehro Pefhany" wrote in message
...
On Tue, 10 Jun 2008 14:43:26 -0500, Ignoramus13673
wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Material removal rate-- there are various tables, and, as always, it
depends on various factors, but by one rule of thumb 20HP would remove
about 30 in^3 per minute of steel or maybe 100 in^3 of aluminum.

If you want to turn something 12" in diameter down to 3" over an 8"
length, that's um.. around 850 in^3 if I did the math right, so it
would take almost half an hour for steel and 10 minutes for aluminum
if HP was the limiting factor.

Which reminds me of a cartoon we ran in _American Machinist_ in the
mid-'70s. The caption was, "Why productivity is so low in the Soviet Union."

--
Ed Huntress

On Tue, 10 Jun 2008 16:53:01 -0400, "Ed Huntress"
wrote:


"Spehro Pefhany" wrote in message
.. .
On Tue, 10 Jun 2008 14:43:26 -0500, Ignoramus13673
wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Material removal rate-- there are various tables, and, as always, it
depends on various factors, but by one rule of thumb 20HP would remove
about 30 in^3 per minute of steel or maybe 100 in^3 of aluminum.

If you want to turn something 12" in diameter down to 3" over an 8"
length, that's um.. around 850 in^3 if I did the math right, so it
would take almost half an hour for steel and 10 minutes for aluminum
if HP was the limiting factor.

Which reminds me of a cartoon we ran in _American Machinist_ in the
mid-'70s. The caption was, "Why productivity is so low in the Soviet Union."

So, what did the cartoon show?
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

"Spehro Pefhany" wrote in message
...
On Tue, 10 Jun 2008 16:53:01 -0400, "Ed Huntress"
wrote:


"Spehro Pefhany" wrote in message
. ..
On Tue, 10 Jun 2008 14:43:26 -0500, Ignoramus13673
wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Material removal rate-- there are various tables, and, as always, it
depends on various factors, but by one rule of thumb 20HP would remove
about 30 in^3 per minute of steel or maybe 100 in^3 of aluminum.

If you want to turn something 12" in diameter down to 3" over an 8"
length, that's um.. around 850 in^3 if I did the math right, so it
would take almost half an hour for steel and 10 minutes for aluminum
if HP was the limiting factor.

Which reminds me of a cartoon we ran in _American Machinist_ in the
mid-'70s. The caption was, "Why productivity is so low in the Soviet
Union."

So, what did the cartoon show?
Best regards,
Spehro Pefhany

A lathe operator turning a piece of stock around 12" diameter down to maybe
3" diameter, over an 8" length. Then he held the part up with pride. g

--
Ed Huntress

On Tue, 10 Jun 2008 17:45:50 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


"Spehro Pefhany" wrote in message
.. .

So, what did the cartoon show?

A lathe operator turning a piece of stock around 12" diameter down to maybe
3" diameter, over an 8" length. Then he held the part up with pride. g

That's an expensive practice, wot? It's amazing that the USSR was
unionized, though. That sounds like union practices.

--
Besides the noble art of getting things done, there is a nobler art of
leaving things undone. The wisdom of life consists in the elimination
of nonessentials. -- Lin Yutang

Ignoramus13673 wrote:

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.


Our cast iron pulley cells (cnc) have 35 hp spindles and most parts are 12" dia or
smaller. Even the machines turning aluminum castings have 15 hp spindles and sometimes
our gang roughing groovers get the belts to slip. Plastic muli-vee belts suck.

That thing has a 25" swing. 20HP seems reasonable to light depending.

Wes

A friend of mine mentioned he had been turning down some pins for the
prop shafts on a 1000' long Great Lakes ore boat. Start with 8" shaft,
need to turn down 4' of it to 6" in diameter. IIRC he was running about
..330 cut and .250 feed. If you wanted 80 feet per minute cutting speed,
that is 40 rpm. Works out to 6.6 cubic inches of metal per minute. But
you better have a chip breaker to deal with the 80 feet of 1/4" x 1/3"
bar stock you get every minute!

Ignoramus13673 wrote:
This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

"Ignoramus13673" wrote in message
...
This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

--
Due to extreme spam originating from Google Groups, and their
inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/


I worked at a shop years back that had a lathe with a motor that was rated
40 HP continuous duty, and 50 HP intermittent use. We would run it at the
full 50 HP fairly often. Physically it was not a very large machine, but it
sure would make chips!!
Greg

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

I guess it depends on your hobby. I have a 20 hp. Mazak M4 CNC lathe. Nice
machine and useful. But not a watchmakers lathe.

Karl

On Tue, 10 Jun 2008 14:43:26 -0500, with neither quill nor qualm,
Ignoramus13673 quickly quoth:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Go look at pics taken in some of the machine shops during WWII, Ig.
They turned prop shafts for battleships, cruisers, and carriers with
'em. Here is one from more recent years:

www.co.cullman.al.us/.../lufkin_grandopening.htm

--
Besides the noble art of getting things done, there is a nobler art of
leaving things undone. The wisdom of life consists in the elimination
of nonessentials. -- Lin Yutang

On 2008-06-11, Larry Jaques novalidaddress@di wrote:
On Tue, 10 Jun 2008 14:43:26 -0500, with neither quill nor qualm,
Ignoramus13673 quickly quoth:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Go look at pics taken in some of the machine shops during WWII, Ig.
They turned prop shafts for battleships, cruisers, and carriers with
'em. Here is one from more recent years:

www.co.cullman.al.us/.../lufkin_grandopening.htm


Can you post a proper URL Larry?
--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
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posting on Usenet.
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Ignoramus13673 wrote:

On 2008-06-11, Larry Jaques novalidaddress@di wrote:

On Tue, 10 Jun 2008 14:43:26 -0500, with neither quill nor qualm,
Ignoramus13673 quickly quoth:


This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Go look at pics taken in some of the machine shops during WWII, Ig.
They turned prop shafts for battleships, cruisers, and carriers with
'em. Here is one from more recent years:

www.co.cullman.al.us/.../lufkin_grandopening.htm



Can you post a proper URL Larry?

I suppose he means this:
http://www.co.cullman.al.us/Press/lu...andopening.htm

Tom

On 2008-06-11, Tom wrote:
Ignoramus13673 wrote:

On 2008-06-11, Larry Jaques novalidaddress@di wrote:

On Tue, 10 Jun 2008 14:43:26 -0500, with neither quill nor qualm,
Ignoramus13673 quickly quoth:


This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Go look at pics taken in some of the machine shops during WWII, Ig.
They turned prop shafts for battleships, cruisers, and carriers with
'em. Here is one from more recent years:

www.co.cullman.al.us/.../lufkin_grandopening.htm



Can you post a proper URL Larry?

I suppose he means this:
http://www.co.cullman.al.us/Press/lu...andopening.htm

Looks cool. Here's anothger one (scroll 2/3 of the way down)

http://thomascranelibrary.org/shipbu...lant/plant.htm
http://thomascranelibrary.org/shipbu...ages/wpe14.jpg

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

On Tue, 10 Jun 2008 21:01:02 -0500, with neither quill nor qualm,
Ignoramus13673 quickly quoth:

On 2008-06-11, Tom wrote:
Ignoramus13673 wrote:

Can you post a proper URL Larry?

I suppose he means this:
http://www.co.cullman.al.us/Press/lu...andopening.htm

(You got it in one, Tom.)


Looks cool. Here's anothger one (scroll 2/3 of the way down)

http://thomascranelibrary.org/shipbu...lant/plant.htm
http://thomascranelibrary.org/shipbu...ages/wpe14.jpg

Wow, that joggling machine is an amazing tool, too. Stamping out lap
bends in one inch steel plate is not something you "finesse", I
wouldn't think. It's the picture above the lathe, wpe12.jpg.

--
Besides the noble art of getting things done, there is a nobler art of
leaving things undone. The wisdom of life consists in the elimination
of nonessentials. -- Lin Yutang

On Tue, 10 Jun 2008 20:19:42 -0500, with neither quill nor qualm,
Ignoramus13673 quickly quoth:

On 2008-06-11, Larry Jaques novalidaddress@di wrote:
On Tue, 10 Jun 2008 14:43:26 -0500, with neither quill nor qualm,
Ignoramus13673 quickly quoth:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

Go look at pics taken in some of the machine shops during WWII, Ig.
They turned prop shafts for battleships, cruisers, and carriers with
'em. Here is one from more recent years:

www.co.cullman.al.us/.../lufkin_grandopening.htm


Can you post a proper URL Larry?

Hah! I hadn't noticed that it wasn't one. I snagged it from the
"actual URL" on Google's Images. Googling "lufkin_grandopening.htm"
took me right back to it, though:
http://www.co.cullman.al.us/Press/lu...andopening.htm
The second pic shows a beastie, plus there are a few more big boys in
the cluster of pics at the bottom of the page.

--
Besides the noble art of getting things done, there is a nobler art of
leaving things undone. The wisdom of life consists in the elimination
of nonessentials. -- Lin Yutang

On Tue, 10 Jun 2008 14:43:26 -0500, Ignoramus13673
wrote:

This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.


Any idea of how much pure force it takes to simply spin up a 2' in
diameter chuck, let alone a 10' long work piece of that diameter, in
any reasonable amount of time?

Gunner

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.


Any idea of how much pure force it takes to simply spin up a 2' in
diameter chuck, let alone a 10' long work piece of that diameter, in
any reasonable amount of time?

My 20 hp. lathe has a transmission. There's not enough hp. to start it in
any of the top 4 gears. You have to get it up to speed and then shift up,
like in a car. It still dims the lights on the whole place.

Karl

On 2008-06-11, Karl Townsend wrote:

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.


Any idea of how much pure force it takes to simply spin up a 2' in
diameter chuck, let alone a 10' long work piece of that diameter, in
any reasonable amount of time?

My 20 hp. lathe has a transmission. There's not enough hp. to start it in
any of the top 4 gears. You have to get it up to speed and then shift up,
like in a car. It still dims the lights on the whole place.

Karl, you may be able to buy a soft start inexpensively.

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
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Karl, you may be able to buy a soft start inexpensively.

I've heard of the term. What exactly is it? When you say inexpensive, i
assume used. This machine could use it. So could my Supermax, 5hp.

Karl

On 2008-06-11, Karl Townsend wrote:


Karl, you may be able to buy a soft start inexpensively.

I've heard of the term. What exactly is it? When you say inexpensive, i
assume used. This machine could use it. So could my Supermax, 5hp.

A soft start is a electronic device that makes the motor spin up
gradually instead of producing that infamous "starting current".
It is not a VFD and can only produce 60 Hz, but it modulates the
amount of current available so that the motor would gradually spin
up to its rated frequency.

It may not be acceptable for hard starting loads like compressors,
however, it is used widely for soft starting loads like lathes, fans,
various spindles in general etc.

They are not very expensive used on ebay, even for high HP motors.
Sometimes the sellers describe them as VFDs, which is not true and can
only be explained by ignorance.

http://en.wikipedia.org/wiki/Soft_start

Soft start is an electronics term describing any circuit which is
reduces excess current flow during initial power up.

[edit] Need for soft start

....

Soft starts are sometimes used on larger equipment as well, such as
electric motors in various applications. The current drawn by an
electric motor during a start can be 2 to 10 times the normal
operating current, and this can exceed the supply's ratings if not
controlled.

Finally soft start is widely used on hand held tools to prevent the
tool being jerked out of position when switched on. Jumping of
electric drills was a widespread issue in the 1970s when soft start
was usually not fitted.

[edit] Soft starting methods

There are various ways to implement soft starting.

The most popular for appliances is triac control which ramps up duty
cycle over several cycles.

A method used with some motors is to start with windings in series,
switching them to parallel when partial speed has been reached. This
is commonly known as Y- start.

Increasing supply impedance has a semi soft start effect on motors,
with initial current still being above run current, but by a much
reduced amount. This method is not widely used.

Current limiting and voltage ramp-up in electronic supplies are common
methods of soft starting low voltage loads.



--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
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Ignoramus13673 wrote:
This lathe is advertised as 20 HP:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300231171003

I do not doubt that the ad is true, but I have to wonder why any lathe
would need a 20 HP motor. I have hard times imagining how even a
fraction of that could be expended cutting metal with a single point
lathe bit.

I used a lathe similar to that once for turning the tyres of railway
locomotive wheels.

Best wishes,

Chris