Hello all,

I have a '33 11" SB lathe with a '31 Westinghouse 1/2 HP motor on it. The
motor started acting up so I took it to my local motor shop who got it
running decently, but told me that it would cost a mint to do what needs to
be done to make it right (70 years of oil soaking into the winding
insulation and all that). While the motor works, it doesn't work as well as
it should, and rather than spend more money than it's worth, I'd like to
replace it. The question is; with what?

I've been told that 1931 HP were bigger than 2006 HP and that I should go
with a 3/4 or 1 HP motor to get similar work capacity. That's fine, and my
shop is wired for 110, 220 and I have both a rotary and static phase
converter. My lathe has a screw-on chuck so I don't have a need for instant
reversing (although the lathe is currently wired for reversing and I'd like
to keep that capability). My question is, are there any advantages to 220
or 220 3-phase over 110 when choosing a motor without concern for instant
reversing. IOW, do I get more real power with any of them, less power
consumption, or smoother operation? Are there advantages or disadvantages
that I haven't mentioned? Any types of motors I should stay away from? Any
types of motor that would be good for my application?

I've done a RCM Google search and haven't been able to get these questions
answered, but if anyone had a pointer to an appropriate web site, I'd be
happy to follow it. Keep in mind that I'm an electrical dunce (I had an
electrician install the RPC for my mill) so any conversation about
degaussing the flux capacitance in the field coil windings is likely to
leave me befuddled.

As usual, thanks for the advice and Happy New Year!

Regards,

Peter

On Sun, 01 Jan 2006 04:02:11 GMT, "Peter Grey"
wrote:


Hello all,

I have a '33 11" SB lathe with a '31 Westinghouse 1/2 HP motor on it. The
motor started acting up so I took it to my local motor shop who got it
running decently, but told me that it would cost a mint to do what needs to
be done to make it right (70 years of oil soaking into the winding
insulation and all that). While the motor works, it doesn't work as well as
it should, and rather than spend more money than it's worth, I'd like to
replace it. The question is; with what?

I've been told that 1931 HP were bigger than 2006 HP and that I should go
with a 3/4 or 1 HP motor to get similar work capacity. That's fine, and my
shop is wired for 110, 220 and I have both a rotary and static phase
converter. My lathe has a screw-on chuck so I don't have a need for instant
reversing (although the lathe is currently wired for reversing and I'd like
to keep that capability). My question is, are there any advantages to 220
or 220 3-phase over 110 when choosing a motor without concern for instant
reversing. IOW, do I get more real power with any of them, less power
consumption, or smoother operation? Are there advantages or disadvantages
that I haven't mentioned? Any types of motors I should stay away from? Any
types of motor that would be good for my application?

I've done a RCM Google search and haven't been able to get these questions
answered, but if anyone had a pointer to an appropriate web site, I'd be
happy to follow it. Keep in mind that I'm an electrical dunce (I had an
electrician install the RPC for my mill) so any conversation about
degaussing the flux capacitance in the field coil windings is likely to
leave me befuddled.

As usual, thanks for the advice and Happy New Year!

Regards,

Peter


HP are HP, 1931 or 2006. Motors are usually honestly rated; it's
the guys that sell things with motors in them (Sears, etc) that lie a
lot. 1931 motors were considerably larger (and less efficient)
than today's motors for given HP, though.

I'd put a minimum of 1 HP on a 11" lathe. Up to 2 HP can run OK on a
110 volt singlephase 20 -amp circuit, though I'd probably go with 220
on a 2 HP motor if it's just as easy to go that way.

Many or most single phase induction motors can be reversed if
brought to a full stop before starting in the opposite direction. I
wouldn't "plug reverse" a lathe with a threaded spindle anyway.

Threephase motors will tend to be a bit smaller for given HP, and
they'll run with less vibration -- a plus on a lathe though belt drive
mitigates motor vibration to some extent. They're also cheap when
found surplus. All threephase induction motors are reversable.

Motors usually found on lathes are induction motors, either repulsion
start or capacitor start. Either will work fine.

If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?" Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

"Don Foreman" wrote in message
...


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

On Sun, 01 Jan, Peter Grey wrote:
"Don Foreman" wrote in message
Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Seems like a good application for a 3 phase motor and a VFD to run it.
Speed control, reversing, and fun! Or something. You could definitely
just run a 1750RPM motor that way.


--Donnie

--
Donnie Barnes http://www.donniebarnes.com 879. V.

Peter Grey wrote:
Hello all,

I have a '33 11" SB lathe with a '31 Westinghouse 1/2 HP motor on it. The
motor started acting up so I took it to my local motor shop who got it
running decently, but told me that it would cost a mint to do what needs to
be done to make it right (70 years of oil soaking into the winding
insulation and all that). While the motor works, it doesn't work as well as
it should, and rather than spend more money than it's worth, I'd like to
replace it. The question is; with what?

I've been told that 1931 HP were bigger than 2006 HP and that I should go
with a 3/4 or 1 HP motor to get similar work capacity. That's fine, and my
shop is wired for 110, 220 and I have both a rotary and static phase
converter. My lathe has a screw-on chuck so I don't have a need for instant
reversing (although the lathe is currently wired for reversing and I'd like
to keep that capability). My question is, are there any advantages to 220
or 220 3-phase over 110 when choosing a motor without concern for instant
reversing.
Yes, a 3-phase motor also runs smoother than a single-phase plain
induction motor. Because of the power line cycles, the single-phase
motor is essentially shut off 120 times a second. Capacitor-run motors
are better in this regard, but a 3-phase motor is even smoother. Some
people have been troubled by bad surface finish and other vibration
problems and found DC or 3-phase motors solved the problem.

Later, you can always get a Variable Freq Drive for a 3-phase motor
and have variable speed, too.

Jon

Peter Grey wrote:
"Don Foreman" wrote in message
...


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"


Thanks. I was wondering about those.


Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.


The motor on my lathe runs at 1140 RPM. The space won't allow for pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?
Only that 6-pole motors are larger for the delivered HP, and they are
not as readily available.

Jon

--
www.MachinedThings.com
"Jon Elson" wrote in message
...
Peter Grey wrote:
"Don Foreman" wrote in message
...


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"


Thanks. I was wondering about those.


Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.


The motor on my lathe runs at 1140 RPM. The space won't allow for
pulleys appropriate to use a 1725 RPM motor. Any ramifications or
considerations about 1140 RPM motors?
Only that 6-pole motors are larger for the delivered HP, and they are
not as readily available.

Jon

"Jon Elson" wrote in message
...
Yes, a 3-phase motor also runs smoother than a single-phase plain
induction motor. Because of the power line cycles, the single-phase
motor is essentially shut off 120 times a second. Capacitor-run motors
are better in this regard, but a 3-phase motor is even smoother. Some
people have been troubled by bad surface finish and other vibration
problems and found DC or 3-phase motors solved the problem.

I'm surprised it could make that much difference. The motor that's being
replaced is a 110 repulsion/indeucion motor and the surface finish I get is
acceptable. One motor I'm looking at is a 110 capacitor-start. Any notion
of how that would compare to the old motor?

Later, you can always get a Variable Freq Drive for a 3-phase motor
and have variable speed, too.

I've been given a new Phase-A-Matic static phase converter that I would like
to use rather than hooking in to the RPC I use for my mill. The RPC is
rather noisy in my small shop and I'm hoping the static converter would be
quieter. Would a VFD replace a phase converter or be used in addition to
it? I'm assuming that the VFD will only vary the speed up to the rated RPM.
IOW, a VFD wouldn't allow a 1140 RPM motor to run more than 1140 RPM, but
allow one to choose 800 RPM for example. Does the power go down
proportional to the RPM?



Peter

I vote for 3-phase because the motors on Ebay are very cheap. I've
purchased 1/2 and 3/4 HP 3 phase motors, all new, on Ebay consistently
for less than $60 including shipping. Some have cost me only $30. These
have not been cheapy motors either (Reliance, Westinghouse, etc) I have
remotored a lathe and mill for VFDs. A bandsaw and drill press are
next. The VFDs have cost less than $100 each. Bye bye belt changes.

On Sun, 01 Jan 2006 05:32:45 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
.. .


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

For an 11" lathe you should be looking at something in the 3/4 hp range
to give you the power you will wantto make heavier cuts. 220 volt motors
are preferred over 110 volt since the current is half on the 220. BUT,
for 3/4 HP, the current isn't excessive on the 110 volt. 3 phase motors
are cheaper, smaller, and smoother.

Your need for a 1140 prm motor is a real pain, used/surplus/cheap is not
going to be in your future.

I think I'd look for a 3/4hp cap start cap run 240 volt 1750 motor. Use
a slightly SMALLER drive pulley on the motor and you should be able to
pick up a few hundred rpm over the stock unit.

Peter Grey wrote:
Hello all,

I have a '33 11" SB lathe with a '31 Westinghouse 1/2 HP motor on it. The
motor started acting up so I took it to my local motor shop who got it
running decently, but told me that it would cost a mint to do what needs to
be done to make it right (70 years of oil soaking into the winding
insulation and all that). While the motor works, it doesn't work as well as
it should, and rather than spend more money than it's worth, I'd like to
replace it. The question is; with what?

I've been told that 1931 HP were bigger than 2006 HP and that I should go
with a 3/4 or 1 HP motor to get similar work capacity. That's fine, and my
shop is wired for 110, 220 and I have both a rotary and static phase
converter. My lathe has a screw-on chuck so I don't have a need for instant
reversing (although the lathe is currently wired for reversing and I'd like
to keep that capability). My question is, are there any advantages to 220
or 220 3-phase over 110 when choosing a motor without concern for instant
reversing. IOW, do I get more real power with any of them, less power
consumption, or smoother operation? Are there advantages or disadvantages
that I haven't mentioned? Any types of motors I should stay away from? Any
types of motor that would be good for my application?

I've done a RCM Google search and haven't been able to get these questions
answered, but if anyone had a pointer to an appropriate web site, I'd be
happy to follow it. Keep in mind that I'm an electrical dunce (I had an
electrician install the RPC for my mill) so any conversation about
degaussing the flux capacitance in the field coil windings is likely to
leave me befuddled.

As usual, thanks for the advice and Happy New Year!

Regards,

Peter

"lens" wrote in message
oups.com...
I vote for 3-phase because the motors on Ebay are very cheap. I've
purchased 1/2 and 3/4 HP 3 phase motors, all new, on Ebay consistently
for less than $60 including shipping. Some have cost me only $30. These
have not been cheapy motors either (Reliance, Westinghouse, etc) I have
remotored a lathe and mill for VFDs. A bandsaw and drill press are
next. The VFDs have cost less than $100 each. Bye bye belt changes.

Any take on Franklin Electric motors?

Peter

--
www.MachinedThings.com
"Don Foreman" wrote in message
...
On Sun, 01 Jan 2006 05:32:45 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
. ..


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

--
www.MachinedThings.com
"Don Foreman" wrote in message
...
On Sun, 01 Jan 2006 05:32:45 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
. ..


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

--
www.MachinedThings.com
"Don Foreman" wrote in message
...
On Sun, 01 Jan 2006 05:32:45 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
. ..


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

"Don Foreman" wrote in message
...

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

There seem to be bunch of 3-phase 1140 RPM motors on e-bay. Without the
VFD, do they offer any advantage over the 110 1140 motor?

The problem with the space is such that I can not run the pulleys required
to use a 1750 RPM motor. The motor itself could be quite a bit bigger than
what I have. Of course, a 1750 RPM motor with a VFD woud get me where I
want to go, and allow a higher spindle RPM which I've been longing for. I
can always get a electrcian to help me with the wiring...

Peter

"Peter Grey" wrote in message
ink.net...


--
www.MachinedThings.com
"Don Foreman" wrote in message
...
On Sun, 01 Jan 2006 05:32:45 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
...


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for
pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

"Peter Grey" wrote in message
ink.net...


--
www.MachinedThings.com
"Don Foreman" wrote in message
...
On Sun, 01 Jan 2006 05:32:45 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
...


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for
pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

"Peter Grey" wrote in message
news


--
www.MachinedThings.com
"Don Foreman" wrote in message
...
On Sun, 01 Jan 2006 05:32:45 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
...


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for
pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

On Sun, 01 Jan 2006 07:28:12 GMT, "Peter Grey"
wrote:




I think..its time for you to get a real news reader

X-Newsreader: Microsoft Outlook Express 6.00.2900.2527

Is not cutting it for you anymore.

Might I suggest Agent?

www.forteinc.com

Try the Free Agent for a bit

Gunner


"Peter Grey" wrote in message
news


--
www.MachinedThings.com
"Don Foreman" wrote in message
...
On Sun, 01 Jan 2006 05:32:45 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
m...


If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?"

Thanks. I was wondering about those.

Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.

The motor on my lathe runs at 1140 RPM. The space won't allow for
pulleys
appropriate to use a 1725 RPM motor. Any ramifications or considerations
about 1140 RPM motors?

Peter

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics






"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Peter,
There have been a lot of replies to your post. I have a late model of your
machine. I bought it new from SB direct. I have changed motors. So my
experience is first hand. Anything more than 3/4 HP is a waste because it
won't couple to the chuck. The drive slips first. Most of those lathes work
on single phase because of where they are used. This lathe is very light and
flexes under load change. Single phase motors are not smooth. They
accelerate and decelerate under load at line frequency. This can be observed
in finish cuts in high gear on your machine. Three phase motors are much
smoother and this finish problem goes away. I have a brand new OEM never
used 60 hz single phase motor for your machine that I will never use. You
are welcome to it, but I assure you a 3/4 HP 3 phase motor is much better.
Steve

"Peter Grey" wrote in message
ink.net...

Hello all,

I have a '33 11" SB lathe with a '31 Westinghouse 1/2 HP motor on it. The
motor started acting up so I took it to my local motor shop who got it
running decently, but told me that it would cost a mint to do what needs
to be done to make it right (70 years of oil soaking into the winding
insulation and all that). While the motor works, it doesn't work as well
as it should, and rather than spend more money than it's worth, I'd like
to replace it. The question is; with what?

I've been told that 1931 HP were bigger than 2006 HP and that I should go
with a 3/4 or 1 HP motor to get similar work capacity. That's fine, and
my shop is wired for 110, 220 and I have both a rotary and static phase
converter. My lathe has a screw-on chuck so I don't have a need for
instant reversing (although the lathe is currently wired for reversing and
I'd like to keep that capability). My question is, are there any
advantages to 220 or 220 3-phase over 110 when choosing a motor without
concern for instant reversing. IOW, do I get more real power with any of
them, less power consumption, or smoother operation? Are there advantages
or disadvantages that I haven't mentioned? Any types of motors I should
stay away from? Any types of motor that would be good for my application?

I've done a RCM Google search and haven't been able to get these questions
answered, but if anyone had a pointer to an appropriate web site, I'd be
happy to follow it. Keep in mind that I'm an electrical dunce (I had an
electrician install the RPC for my mill) so any conversation about
degaussing the flux capacitance in the field coil windings is likely to
leave me befuddled.

As usual, thanks for the advice and Happy New Year!

Regards,

Peter

The problem with the space is such that I can not run the pulleys required
to use a 1750 RPM motor. The motor itself could be quite a bit bigger
than what I have. Of course, a 1750 RPM motor with a VFD woud get me
where I want to go, and allow a higher spindle RPM which I've been longing
for. I

You'd be EXTREMELY happy with the final result here. Variable speed is real
nice. Its got me plumb spoiled, can't have a lathe without this anymore.

Your costs go up as you increase motor size, but you should be aware that a
VFD/motor running at 1/2 speed has 1/2 the horsepower, etc. So, if you'll
use this at low speeds you need to oversize the motor and VFD. Of course you
could still change belts for low speed and not have this problem.

Karl

Any take on Franklin Electric motors?

This is another name brand motor. I wouldn't be afraid of it.

I've been given a new Phase-A-Matic static phase converter that I would
like to use rather than hooking in to the RPC I use for my mill. The RPC
is rather noisy in my small shop and I'm hoping the static converter would
be quieter. Would a VFD replace a phase converter or be used in addition
to it? I'm assuming that the VFD will only vary the speed up to the rated
RPM. IOW, a VFD wouldn't allow a 1140 RPM motor to run more than 1140 RPM,
but allow one to choose 800 RPM for example. Does the power go down
proportional to the RPM?

Phase a matic developes 2/3 of motor hp. It will work though as long as you
keep this in mind.

VFDs would replace the phase converter need. As a rule of thumb you can run
a VFD up to twice the motor rated RPM. I've done it on several motors and
nevere has a problem. Yes, power goes down porportional to RPM.

BTW, you'd LOVE a VFD on that mill also.

Karl

Good advice, Don. Until you get bigger than 1-1/2 HP, three phase
doesn't have much advantage.
Bugs

"Karl Townsend" remove .NOT wrote in
message ink.net...
VFDs would replace the phase converter need. As a rule of thumb you can
run a VFD up to twice the motor rated RPM. I've done it on several motors
and nevere has a problem. Yes, power goes down porportional to RPM.

BTW, you'd LOVE a VFD on that mill also.

So does this mean that a 1140 motor becomes 2280 RPM motor? At twice the
power?

Peter

"Steve Lusardi" wrote in message
...
Peter,
There have been a lot of replies to your post. I have a late model of your
machine. I bought it new from SB direct. I have changed motors. So my
experience is first hand. Anything more than 3/4 HP is a waste because it
won't couple to the chuck. The drive slips first.

I do realize this. I'm figuring that since I have a "fuse" in the belt,
that more HP isn't going to hurt too much and I may have an opportunity to
get a free new 3 phase 3 HP motor. It's an 1800 RPM motor and I wasn't
going to use it because of not having pulley room, but the VFD idea may make
it useable, if I can get someone to install it so I don't kill myself. I'm
just trying to understand my options.

I have a brand new OEM never used 60 hz single phase motor for your
machine that I will never use. You are welcome to it

Is this an OEM motor from the '30s? It might cost a couple hundred bucks
just to ship it! I damn near threw my back out getting mine into my
truck. It must wiegh 100 pounds

Peter

Peter,

Is this an OEM motor from the '30s? It might cost a couple hundred bucks
just to ship it! I damn near threw my back out getting mine into my
truck. It must wiegh 100 pounds

I bought a shop crane (Torin Jacks - $140 complete w/ folding legs!) to
handle my mill and now wonder how I ever got along with out it. At 100
lbs, I would be tempted to just lift the thing myself, but if there were
any "up and over" tricks, it would be well worth the time to break out
the crane.

A related technique question for the group: have any of you used a shop
crane/engine hoist to flip something? I managed to assemble and flip my
table saw myself, and before I had the crane. The essential tricks were
deviating from instructions (they wanted me to install a wheel that
would have been toast had it been in place at the time), and an
improvised wood stop that allowed me to concentrate on lifting instead
of lifting and turning. The plan was to try it, aborting at the first
sign of trouble; it really wasn't too bad. The motor was not attached
which helped some. Is there a safe way to do something like that using
a shop crane?

Bill

On Sun, 01 Jan 2006 07:25:49 GMT, "Peter Grey"
wrote:




"Don Foreman" wrote in message
.. .

Choices a

1: find a suitable 1140 RPM motor or rebuild the one you have
2: modify the space available
3: use a threephase motor and a VFD -- rotsa ruck with that if you're
not comfy wiht electrics

There seem to be bunch of 3-phase 1140 RPM motors on e-bay. Without the
VFD, do they offer any advantage over the 110 1140 motor?

Less vibration, easy reversing, perhaps slightly smaller size for
given HP.

The problem with the space is such that I can not run the pulleys required
to use a 1750 RPM motor. The motor itself could be quite a bit bigger than
what I have. Of course, a 1750 RPM motor with a VFD woud get me where I
want to go, and allow a higher spindle RPM which I've been longing for. I
can always get a electrcian to help me with the wiring...

Peter

On Sun, 01 Jan 2006 11:18:42 GMT, "Karl Townsend"
remove .NOT wrote:


Any take on Franklin Electric motors?

This is another name brand motor. I wouldn't be afraid of it.

I've been given a new Phase-A-Matic static phase converter that I would
like to use rather than hooking in to the RPC I use for my mill. The RPC
is rather noisy in my small shop and I'm hoping the static converter would
be quieter. Would a VFD replace a phase converter or be used in addition
to it? I'm assuming that the VFD will only vary the speed up to the rated
RPM. IOW, a VFD wouldn't allow a 1140 RPM motor to run more than 1140 RPM,
but allow one to choose 800 RPM for example. Does the power go down
proportional to the RPM?

Phase a matic developes 2/3 of motor hp. It will work though as long as you
keep this in mind.

A threephase motor run from a Phase a matic willl not run as smoothly
as it does on true 3-phase power. Whether that matters or not depends
on the application.

"Don Foreman" wrote in message
...
A threephase motor run from a Phase a matic willl not run as smoothly
as it does on true 3-phase power. Whether that matters or not depends
on the application.

Does that hold true for a RPC as well?

Peter

In article . net,
says...



"Karl Townsend" remove .NOT wrote in
message ink.net...
VFDs would replace the phase converter need. As a rule of thumb you can
run a VFD up to twice the motor rated RPM. I've done it on several motors
and nevere has a problem. Yes, power goes down porportional to RPM.

BTW, you'd LOVE a VFD on that mill also.

So does this mean that a 1140 motor becomes 2280 RPM motor? At twice the
power?


No, if the drive is set to match the motor's nameplate, the motor will
deliver constant torque up to nameplate speed and constant HP above.

Ned Simmons

Jon Elson wrote:
Peter Grey wrote:

Hello all,

I have a '33 11" SB lathe with a '31 Westinghouse 1/2 HP motor on it.
The motor started acting up so I took it to my local motor shop who
got it running decently, but told me that it would cost a mint to do
what needs to be done to make it right (70 years of oil soaking into
the winding insulation and all that). While the motor works, it
doesn't work as well as it should, and rather than spend more money
than it's worth, I'd like to replace it. The question is; with what?

I've been told that 1931 HP were bigger than 2006 HP and that I should
go with a 3/4 or 1 HP motor to get similar work capacity. That's
fine, and my shop is wired for 110, 220 and I have both a rotary and
static phase converter. My lathe has a screw-on chuck so I don't have
a need for instant reversing (although the lathe is currently wired
for reversing and I'd like to keep that capability). My question is,
are there any advantages to 220 or 220 3-phase over 110 when choosing
a motor without concern for instant reversing.

Yes, a 3-phase motor also runs smoother than a single-phase plain
induction motor. Because of the power line cycles, the single-phase
motor is essentially shut off 120 times a second. Capacitor-run motors
are better in this regard, but a 3-phase motor is even smoother. Some
people have been troubled by bad surface finish and other vibration
problems and found DC or 3-phase motors solved the problem.

Later, you can always get a Variable Freq Drive for a 3-phase motor
and have variable speed, too.

Jon

Not only does a single phase motor shut off 120 times a second it goes
through 120 cycles of maximum holding force then maximum pushing force

a three phase never puts the motor into that type of position in itself.

when the input feed is at 120V it is actually trying to decelerate the
motor because the voltage on the field is at its strongest and keeping
the motors rotor in place (or at least trying to)

As the motor slidees down to cross 0 its pushing power is at maximum but
it loses the voltage to keep the field going so the field collapses then
rebuilds.

Its the current that moves the motors not the voltage

the same thing happens in three phase but there are always 2two other
phases that have a decent voltage and pushing power happening. It
creates a much more even power transmission

The thing is Is the lathe a heavy enough load to present that BAD of a
load to the single phase motor or are you taking heavy enough cuts to do
so? and is the mass of spinning steel heavy enough that its own inertia
will smooth out the inconsistent power given by the motor?

Odds are if the lathe worked fine on an 85 year old motor in single
phase it will work fine winth a modern single phase motor

As for the HP thing its both right and wrong

BTW a 1931 horsepower i beleive wored out to about 785 watts or close to
it and an SI horsepower (And electronics has all gone to SI) is 750
watts. (about a 5% power loss) BUT the new motors are much more than 5%
more efficient at transferring electrical energy to rotational energy

SO the new motor uses a little less power to do more work

Brent

Hey Peter, its Paul T., your lathes previous owner.

Sad to hear your motor is crapping out, I thought for sure that thing would
outlast me.

I vote for a 1HP 1725 RPM 220 volt 3 phase motor with a VFD, it will be the
cheapest one to buy, and often you can find used 3 phase motors in the 1 to
3 hp range for next to nothing since most home users are looking for single
phase motors.

When the VFD is set at 40 hz. you'll be at your stock speed, and although
the motor HP will be reduced, it will still be more than 1/2 HP. You'll get
useful power from the motor over the speed range of 30 to 120 hz., with
around half power at the endpoints. I take my motors all the way down to 12
to 15 hz. when tapping, and the reduced power actually helps you then,
acting as a "safety" clutch. A 2HP motor would be ok if you find a good deal
on one, 3HP would be overkill on that machine in my opinion, but if you find
one cheap, what the heck. Keep in mind the VFD's cost more for the higher HP
motors.

If you run the motor slow alot, put a 6" pancake fan on it to help cool it,
some guys get fancy and use a thermal snap switch to turn the fan on and
off. I don't run my machines slow very often or for very long, so I haven't
needed to add fans to either my lathe or mill motors.

I've got 3 Teco/Westinghouse VFD's I got from www.dealerselectric.com and
I'm pretty happy with them. Look there for your motor also, they often have
deals on VFD/motor bundles. The Teco manuals stink but they have a helpful
guy available on an 800 number. Wiring them up is easy, just single phase
220 in and 3 wires directly connected to your motor. You can also wire
control lines to start, stop and reverse the motor, keep that cool old motor
switch and wire it to the control input on the VFD, this is also easy to do.
If you get a Teco VFD, before starting it change the default output
frequency, for some dumb reason they send them from the factory set at 5hz.
Most motors won't even spin with a 5hz input, so a lot of Teco buyers think
the VFD is busted when they get it.

Another source for VFD's is www.automationdirect.com .

I would be careful running that lathe over the stock speed, remember its got
plain bearings on the spindle and you don't want to hurt those. It would
probably be a good idea to get some input from some SB specialists on how
fast you can run that machine without hurting the bearings.

Send me an email or give me a buzz if you need more input on deciding how to
replace the motor.

Paul T.

Finish issues with single phase motors on an engine lathe? The rotating mass
of the motor, power transmission, gear train, spindle, chuck, & work will
negate any such issue. You guys are chasing windmills.

A 3/4 to 1 Hp motor would be fine. As for speed of 1140 vs 1725,
check/measure your all of the pulley reductions and see how the spindle
speeds compare to Southbends specs in "How to run a Lathe" or a old
Southbend brochure.

Single vs 3 phase? Single phase may be easier if it eliminates having to
start a converter every time. Wiring a drum switch for requires more wiring
with single, 7 leads as I recall. 3 phase makes for easier wiring. If you
have pushbutton start you will need to check the contactor for compatibility
either way, along with the coil voltage.

VFD on a Southbend, i thinks thats overkill, the three step pulley works
fine.

As for this oft mentioned theory of threaded spindle nose chucks unscrewing
when going into instant reverse... My 5 S/B's from 10" to 16" all with
threaded spindles this has never happened, and when I was in school many
years ago, our shop had 40 S/B heavy 10's with threaded spindles, and the
students often reversed rotating chucks, never saw a chuck come off, nor
were we warned not to do it.

With all the dire warnings I read here about threaded spindles, kinda makes
ya wonder how machinists survived until the advent of camlock spindles.....


Tony

"Steve Lusardi" wrote in message
...
Peter,
There have been a lot of replies to your post. I have a late model of your
machine. I bought it new from SB direct. I have changed motors. So my
experience is first hand. Anything more than 3/4 HP is a waste because it
won't couple to the chuck. The drive slips first. Most of those lathes
work
on single phase because of where they are used. This lathe is very light
and
flexes under load change. Single phase motors are not smooth. They
accelerate and decelerate under load at line frequency. This can be
observed
in finish cuts in high gear on your machine. Three phase motors are much
smoother and this finish problem goes away. I have a brand new OEM never
used 60 hz single phase motor for your machine that I will never use. You
are welcome to it, but I assure you a 3/4 HP 3 phase motor is much better.
Steve

"Peter Grey" wrote in message
ink.net...

Hello all,

I have a '33 11" SB lathe with a '31 Westinghouse 1/2 HP motor on it.
The
motor started acting up so I took it to my local motor shop who got it
running decently, but told me that it would cost a mint to do what needs
to be done to make it right (70 years of oil soaking into the winding
insulation and all that). While the motor works, it doesn't work as
well
as it should, and rather than spend more money than it's worth, I'd like
to replace it. The question is; with what?

I've been told that 1931 HP were bigger than 2006 HP and that I should
go
with a 3/4 or 1 HP motor to get similar work capacity. That's fine, and
my shop is wired for 110, 220 and I have both a rotary and static phase
converter. My lathe has a screw-on chuck so I don't have a need for
instant reversing (although the lathe is currently wired for reversing
and
I'd like to keep that capability). My question is, are there any
advantages to 220 or 220 3-phase over 110 when choosing a motor without
concern for instant reversing. IOW, do I get more real power with any
of
them, less power consumption, or smoother operation? Are there
advantages
or disadvantages that I haven't mentioned? Any types of motors I should
stay away from? Any types of motor that would be good for my
application?

I've done a RCM Google search and haven't been able to get these
questions
answered, but if anyone had a pointer to an appropriate web site, I'd be
happy to follow it. Keep in mind that I'm an electrical dunce (I had an
electrician install the RPC for my mill) so any conversation about
degaussing the flux capacitance in the field coil windings is likely to
leave me befuddled.

As usual, thanks for the advice and Happy New Year!

Regards,

Peter

Plenty of sound advice, but there is one thing that hasn't been
mentioned. Modern motors are more compact than old motors, so you may
well be able to fit a more powerful motor than the original 3/4 hp.
There is a down side to doing this, though. Should anything go wrong
(say the tool sticks in the work, or you're tired and run the carriage
into the chuck, etc.) a more powerful motor is more likely to do major
damage to your workpiece and/or lathe. In this case you might be saved
by the belt drive slipping, but if so a larger motor is wasted.

Best wishes,

Chris

According to Bugs :
Good advice, Don. Until you get bigger than 1-1/2 HP, three phase
doesn't have much advantage.

*At* 1-1/2 HP, a single-phase motor wired for 120VAC tends to
trip the breaker on startup when belted for fairly high spindle speeds.
(At least in an outlet with a 15-amp breaker and a small shared load.)

Re-wiring my Clausing for 240VAC eliminated the problem
entirely.

Enjoy,
DoN.
--
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" wrote in message
ervers.com...
According to Bugs :
Good advice, Don. Until you get bigger than 1-1/2 HP, three phase
doesn't have much advantage.

*At* 1-1/2 HP, a single-phase motor wired for 120VAC tends to
trip the breaker on startup when belted for fairly high spindle speeds.
(At least in an outlet with a 15-amp breaker and a small shared load.)

I think you're saying that it would be load dependant, yes? IOW, if I
started the mtor and then engaged the drive belt, wouldn't that minimize
breaker tripping?

Peter

"Christopher Tidy" wrote in message
...
Plenty of sound advice, but there is one thing that hasn't been mentioned.
Modern motors are more compact than old motors, so you may well be able to
fit a more powerful motor than the original 3/4 hp. There is a down side
to doing this, though. Should anything go wrong (say the tool sticks in
the work, or you're tired and run the carriage into the chuck, etc.) a
more powerful motor is more likely to do major damage to your workpiece
and/or lathe. In this case you might be saved by the belt drive slipping,
but if so a larger motor is wasted.

The major reason for me to go with a 3HP 3-phase motor is that I can get it
for free... Which gives me money to buy a VFD if I decide to go that way.

Peter

I think the shop man was trying to talk simple talk - he means the insulation
and wire is far improved today so the same horse power can be smaller. Therefore
in the same package you can get larger horsepower.

My case is much the same - I have a 1946 Sears ball bearing !! motor. 1/3 Hp.
It is over 12" tall - large cast iron. That baby sits on the counter when it wants to!

I think a 5 or 10 Hp or more - could be put in the form factor.

Martin

Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder



Don Foreman wrote:
On Sun, 01 Jan 2006 04:02:11 GMT, "Peter Grey"
wrote:


Hello all,

I have a '33 11" SB lathe with a '31 Westinghouse 1/2 HP motor on it. The
motor started acting up so I took it to my local motor shop who got it
running decently, but told me that it would cost a mint to do what needs to
be done to make it right (70 years of oil soaking into the winding
insulation and all that). While the motor works, it doesn't work as well as
it should, and rather than spend more money than it's worth, I'd like to
replace it. The question is; with what?

I've been told that 1931 HP were bigger than 2006 HP and that I should go
with a 3/4 or 1 HP motor to get similar work capacity. That's fine, and my
shop is wired for 110, 220 and I have both a rotary and static phase
converter. My lathe has a screw-on chuck so I don't have a need for instant
reversing (although the lathe is currently wired for reversing and I'd like
to keep that capability). My question is, are there any advantages to 220
or 220 3-phase over 110 when choosing a motor without concern for instant
reversing. IOW, do I get more real power with any of them, less power
consumption, or smoother operation? Are there advantages or disadvantages
that I haven't mentioned? Any types of motors I should stay away from? Any
types of motor that would be good for my application?

I've done a RCM Google search and haven't been able to get these questions
answered, but if anyone had a pointer to an appropriate web site, I'd be
happy to follow it. Keep in mind that I'm an electrical dunce (I had an
electrician install the RPC for my mill) so any conversation about
degaussing the flux capacitance in the field coil windings is likely to
leave me befuddled.

As usual, thanks for the advice and Happy New Year!

Regards,

Peter



HP are HP, 1931 or 2006. Motors are usually honestly rated; it's
the guys that sell things with motors in them (Sears, etc) that lie a
lot. 1931 motors were considerably larger (and less efficient)
than today's motors for given HP, though.

I'd put a minimum of 1 HP on a 11" lathe. Up to 2 HP can run OK on a
110 volt singlephase 20 -amp circuit, though I'd probably go with 220
on a 2 HP motor if it's just as easy to go that way.

Many or most single phase induction motors can be reversed if
brought to a full stop before starting in the opposite direction. I
wouldn't "plug reverse" a lathe with a threaded spindle anyway.

Threephase motors will tend to be a bit smaller for given HP, and
they'll run with less vibration -- a plus on a lathe though belt drive
mitigates motor vibration to some extent. They're also cheap when
found surplus. All threephase induction motors are reversable.

Motors usually found on lathes are induction motors, either repulsion
start or capacitor start. Either will work fine.

If you're not comfortable messing around with electrics, I'd stay away
from the "treadmill" motors that offer variable speed. They require
electronic controllers, and the ones that come with them often crap
out -- then you have the problem of "now what?" Go with an induction
motor of the same speed as the original motor. Induction motors come
as 1725 RPM (or so) and 3450 RPM (or so). Yours will very likely be
1725 RPM.


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On Sun, 01 Jan 2006 18:36:14 GMT, "Peter Grey"
wrote:



"Don Foreman" wrote in message
.. .
A threephase motor run from a Phase a matic willl not run as smoothly
as it does on true 3-phase power. Whether that matters or not depends
on the application.

Does that hold true for a RPC as well?

No or much less so, depending on how well (or if) l the RPC is
"tuned". If perfectly tuned for a given load then there will be no
vibration or torque ripple, but even untuned it will be smoother
than single-phase -- which is what a Phase a matic supplies once the
motor is started.

Don't make too much of this. I have a 9" beltdrive Logan lathe
with a singlephase motor and never noticed any problem. Levin
jeweller's lathes use singlephase motors and can do exquisitely fine
work. I'd say don't worry about 3phase vs singlephase, use
whatever induction motor you find that fits your application.

If you want to go with VFD or think you might want to later, then
definitely go with a 3phase motor, even if you run it on single phase
(Phase a matic) for a while.