Hi Guys,

Once again I am here with my hat in hand humbly requesting your assistance.
As some of you know, I am in the process of purchasing a Colchester Circa
1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase motor. Will I be
able to run it successfully on a static phase converter?

Thanks in advance for the help.

Regards.

Joe...

JB,
I'd say probably, errr welll, make that maybe. Do this: Get in touch with
Phase-A-Matic, large maker of static phase converters. Be prepared to give
them the name plate information from the motor.

Bob Swinney
"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase converter?

Thanks in advance for the help.

Regards.

Joe...

Thank you for the advice, Robert.

Joe
"Robert Swinney" wrote in message
...
JB,
I'd say probably, errr welll, make that maybe. Do this: Get in touch with
Phase-A-Matic, large maker of static phase converters. Be prepared to
give them the name plate information from the motor.

Bob Swinney
"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase
converter?

Thanks in advance for the help.

Regards.

Joe...

"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase converter?

Thanks in advance for the help.

Regards.

Joe...

Joe

I am pretty sure you would be content with the performance of a lathe at
home with a 5 HP 3 phase motor powered with single phase.
You probably wont be content with its performance if you intend to run it
loaded over about 4 HP for extended periods.
I'm impressed with the ability of a lathe like that being able to reverse
quite quickly.

Jerry

"Jerry Martes" wrote in message
news:6Ai3f.21174$Tn5.14651@trnddc08...

"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase
converter?

Thanks in advance for the help.

Regards.

Joe...

Joe

I am pretty sure you would be content with the performance of a lathe at
home with a 5 HP 3 phase motor powered with single phase.
You probably wont be content with its performance if you intend to run it
loaded over about 4 HP for extended periods.
I'm impressed with the ability of a lathe like that being able to reverse
quite quickly.

Jerry


Jerry,

Thanks for the help. I don't think I'll be loading it up over 4 HP,
especially for long periods of time. My other concern is whether the two
speed motor will work with a static converter. Some say yes, some say no
and some say maybe.

Thanks again.

Joe...

Reversing could get interesting. That can put a lot of stress on a
phase converter. I've had the situation where a small rotarty would
reverse instead of the lathe, a situation that could really make your
day.

Paul Amaranth wrote:
Reversing could get interesting. That can put a lot of stress on a
phase converter. I've had the situation where a small rotarty would
reverse instead of the lathe, a situation that could really make your
day.

You could get around this simply by pausing with the switch in the off
position until the spindle stops, then applying the power in reverse, right?

Chris

Rotary phase converters are cheap and effective, build your own.

JB wrote:

Hi Guys,

Once again I am here with my hat in hand humbly requesting your assistance.
As some of you know, I am in the process of purchasing a Colchester Circa
1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase motor. Will I be
able to run it successfully on a static phase converter?

Thanks in advance for the help.

Regards.

Joe...

"Christopher Tidy" wrote in message
...
Paul Amaranth wrote:
Reversing could get interesting. That can put a lot of stress on a
phase converter. I've had the situation where a small rotarty would
reverse instead of the lathe, a situation that could really make your
day.

You could get around this simply by pausing with the switch in the off
position until the spindle stops, then applying the power in reverse,
right?

Chris


True, but the value of instant reverse is lost. There are times when that
feature is very valuable to the guy on the machine. Tapping a hole with a
tap in the spindle comes to mind. Failure to reverse instantly could
prove expensive.

Harold

In article ,
says...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your assistance.
As some of you know, I am in the process of purchasing a Colchester Circa
1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase motor. Will I be
able to run it successfully on a static phase converter?


The only 3 phase motor I've not been able to run on a
properly sized static converter is the 2 speed motor on my
Feeler HLVH clone. Whether this is due to something common
to all 2 speed motors, or peculiar to this specific motor,
I can't say.

Bob's suggestion to ask Phase-a-Matic is sound advice.

Another option is a VFD, which is what I did on my lathe.

Ned Simmons

On Wed, 12 Oct 2005 21:28:59 -0400, "JB" wrote:


Thanks for the help. I don't think I'll be loading it up over 4 HP,
especially for long periods of time. My other concern is whether the two
speed motor will work with a static converter. Some say yes, some say no
and some say maybe.

My lathe also has a two-speed motor, rated at 5 HP on high speed and 3
HP on low speed. I could start it in either mode with a static
converter -- but not with the same static converter, or at least not
with the same capacitance.

There may be a way to trick a relay into the lathe's wiring so when
the high-speed mode is engaged more capacitance is switched into the
static converter.

Another option would be to manually switch the converter when you
change speeds.

A large enough rotary converter, probably 10 HP idler, would start
it in either mode.

you may find that a VFD costs about the same as a static converter (unless
you happen to have the parts and plan on building it yourself) - look for a
used one


"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase converter?

Thanks in advance for the help.

Regards.

Joe...

According to Christopher Tidy :
Paul Amaranth wrote:
Reversing could get interesting. That can put a lot of stress on a
phase converter. I've had the situation where a small rotarty would
reverse instead of the lathe, a situation that could really make your
day.

You could get around this simply by pausing with the switch in the off
position until the spindle stops, then applying the power in reverse, right?

Thus eliminating the "reverse it quite quickly" which was
promised about four articles back-thread. :-)

If you want to do this, you want a hefty rotary phase converter.
I don't think that a "static" phase converter as made by "Phase-O-Matic"
could handle a two-speed three-phase motor very well. It will start
well on one or the other speed, but not both.

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 ---

According to william_b_noble :

"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase converter?

you may find that a VFD costs about the same as a static converter (unless
you happen to have the parts and plan on building it yourself) - look for a
used one

Hmm ... a VFD is not likely to work well with a two-speed
three-phase motor -- unless you do all speed switching with the VFD.
You're not supposed to put the switch between the VFD and the motor, as
the voltage spikes from the switching can zap the output transistors of
the VFD.

Here is a place where I feel that a rotary converter
(build-it-yourself) would be the better choice. Or -- you could limit
yourself to one set of windings on the motor, and do all speed changing
with the VFD. For extreme cases (where you *really* need the higher
torque of the low speed, or the higher speed of the high speed), you can
stop the motor entirely (using the VFD's controls), switch to the other
speed at the lathe's switches, and then start the motor back up with the
VFD.

Good Luck,
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 ---

with the VFD. For extreme cases (where you *really* need the higher
torque of the low speed, or the higher speed of the high speed), you can


I don't think that is the case. All 2 speed motors that I have looked
at have a much lower HP rating on Low speed than high speed. Usually
it is less than 1/2. I would venture that a 2 speed motor runing on
high speed but slowed down with a VFD will actually have more
(or at least as much) HP as the same motor runing on low speed.

So in my opinion you can wire the lathe to only use high motor
speed and then use the VFD to generate the low speed without
any loose in motor torque.

Once you use a VFD you will love it. For example I was facing an
8 inch diameter disc. I set the VFD for 20Hz and geared the lathe
for the speed I wanted for full diameter. As the toolbit
works it way towards the center, I gradually increase the VFD
frequency to increase the spindle RPM. It makes facing a big
object so much faster and better.

chuck

JB wrote:

Hi Guys,

Once again I am here with my hat in hand humbly requesting your assistance.
As some of you know, I am in the process of purchasing a Colchester Circa
1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase motor. Will I be
able to run it successfully on a static phase converter?

Thanks in advance for the help.

Regards.

Joe...




I run a 5 horse 2 speed as you are speaking of on a 7.5 horse rotary
built from a phase-a-matic heavy duty static converter rated for 8 hp.
It will NOT start the lathe on the low range but doesn't have any
problems at all with the high range.

Yea, I know...I need bigger. I just wanted to throw out some numbers
that may help. I would suspect that you will not get good service from
a static converter alone. It may be "good enough" for light work in the
speedier gear range but you'll have to seriously oversize it to go into
the low range.

Koz

In article , dnichols@d-and-
d.com says...
According to Christopher Tidy :
Paul Amaranth wrote:
Reversing could get interesting. That can put a lot of stress on a
phase converter. I've had the situation where a small rotarty would
reverse instead of the lathe, a situation that could really make your
day.

You could get around this simply by pausing with the switch in the off
position until the spindle stops, then applying the power in reverse, right?

Thus eliminating the "reverse it quite quickly" which was
promised about four articles back-thread. :-)

If you want to do this, you want a hefty rotary phase converter.
I don't think that a "static" phase converter as made by "Phase-O-Matic"
could handle a two-speed three-phase motor very well. It will start
well on one or the other speed, but not both.


Or in at least one instance (mine), though the HP of both
speeds is within the range of the static converter, the
motor will not start or run properly on either speed.

Ned Simmons

In article , dnichols@d-and-
d.com says...
According to william_b_noble :

"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase converter?

you may find that a VFD costs about the same as a static converter (unless
you happen to have the parts and plan on building it yourself) - look for a
used one

Hmm ... a VFD is not likely to work well with a two-speed
three-phase motor -- unless you do all speed switching with the VFD.
You're not supposed to put the switch between the VFD and the motor, as
the voltage spikes from the switching can zap the output transistors of
the VFD.


I was able to keep all the original functions of the 2-
speed motor on my lathe when I installed a VFD. The two
speed select contactors are between the VFD and the motor
windings, and work as they always have. The direction
commands to the VFD come from the reversing contactor,
which no longer has any direct connection to the motor.

The only thing I can't do (you *can*, but for the reason
you mentioned, *shouldn't*) is switch from hi to lo on the
fly, but that's not a problem now that speed is
controllable with the VFD's speed pot. Most VFDs have a
zero speed output, so it would be possible to prevent
switching the speed select contactors unless the motor is
stopped, but I didn't think it worth the trouble.

Ned Simmons

On 13 Oct 2005 06:24:06 GMT, (DoN. Nichols)
wrote:

According to william_b_noble :

"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase converter?

you may find that a VFD costs about the same as a static converter (unless
you happen to have the parts and plan on building it yourself) - look for a
used one

Hmm ... a VFD is not likely to work well with a two-speed
three-phase motor -- unless you do all speed switching with the VFD.
You're not supposed to put the switch between the VFD and the motor, as
the voltage spikes from the switching can zap the output transistors of
the VFD.

Here is a place where I feel that a rotary converter
(build-it-yourself) would be the better choice. Or -- you could limit
yourself to one set of windings on the motor, and do all speed changing
with the VFD. For extreme cases (where you *really* need the higher
torque of the low speed, or the higher speed of the high speed), you can
stop the motor entirely (using the VFD's controls), switch to the other
speed at the lathe's switches, and then start the motor back up with the
VFD.

Good Luck,
DoN.

Rather than risk frying the old two speed motor on my TM mill, I got a
1 hp. Marathon inverter duty motor to go with the VFD. Good motors
aren't that expensive, or find a used one. The VFD handles generating
the low speed end well.

Pete Keillor

Can you not use the static to start a stand along motor with no load -
spin that up and then the field and power in the windings will in turn
drive the other motors and compensate on-the-fly.

Martin

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



Don Foreman wrote:
On Wed, 12 Oct 2005 21:28:59 -0400, "JB" wrote:


Thanks for the help. I don't think I'll be loading it up over 4 HP,
especially for long periods of time. My other concern is whether the two
speed motor will work with a static converter. Some say yes, some say no
and some say maybe.


My lathe also has a two-speed motor, rated at 5 HP on high speed and 3
HP on low speed. I could start it in either mode with a static
converter -- but not with the same static converter, or at least not
with the same capacitance.

There may be a way to trick a relay into the lathe's wiring so when
the high-speed mode is engaged more capacitance is switched into the
static converter.

Another option would be to manually switch the converter when you
change speeds.

A large enough rotary converter, probably 10 HP idler, would start
it in either mode.

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
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According to Chuck Sherwood :
with the VFD. For extreme cases (where you *really* need the higher
torque of the low speed, or the higher speed of the high speed), you can


I don't think that is the case. All 2 speed motors that I have looked
at have a much lower HP rating on Low speed than high speed. Usually
it is less than 1/2.

Since the horsepower is a function of both the torque and the
speed, this makes sense.

I would venture that a 2 speed motor runing on
high speed but slowed down with a VFD will actually have more
(or at least as much) HP as the same motor runing on low speed.

That sounds good -- as long as the winding for the high-speed
setting can handle the current at low speed operation.

So in my opinion you can wire the lathe to only use high motor
speed and then use the VFD to generate the low speed without
any loose in motor torque.

Excellent suggestion.

Once you use a VFD you will love it. For example I was facing an
8 inch diameter disc. I set the VFD for 20Hz and geared the lathe
for the speed I wanted for full diameter. As the toolbit
works it way towards the center, I gradually increase the VFD
frequency to increase the spindle RPM. It makes facing a big
object so much faster and better.

And -- if you're doing a lot of the same part, you might even
hook a rack gear on the cross-slide, and a pinion on a potentiometer, to
have a result of a constant SFM as you face. This can also help
eliminate chatter at certain speeds and radiuses.

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 ---

According to Ned Simmons :
In article , dnichols@d-and-
d.com says...
According to william_b_noble :

[ ... ]

you may find that a VFD costs about the same as a static converter (unless
you happen to have the parts and plan on building it yourself) - look for a
used one

Hmm ... a VFD is not likely to work well with a two-speed
three-phase motor -- unless you do all speed switching with the VFD.
You're not supposed to put the switch between the VFD and the motor, as
the voltage spikes from the switching can zap the output transistors of
the VFD.


I was able to keep all the original functions of the 2-
speed motor on my lathe when I installed a VFD. The two
speed select contactors are between the VFD and the motor
windings, and work as they always have. The direction
commands to the VFD come from the reversing contactor,
which no longer has any direct connection to the motor.

O.K. The switching between the VFD and the motor is what most
VFD manufacturers explicitly warn against.

The only thing I can't do (you *can*, but for the reason
you mentioned, *shouldn't*) is switch from hi to lo on the
fly, but that's not a problem now that speed is
controllable with the VFD's speed pot. Most VFDs have a
zero speed output, so it would be possible to prevent
switching the speed select contactors unless the motor is
stopped, but I didn't think it worth the trouble.

That depends. If you are the only one who ever uses the lathe,
you can probably depend on remembering the proper operation. However,
with multiple people using the same machine, with a constant potential
for a new hire to not have it locked into his memory yet, I would think
that such an interlock would be well advised.

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 ---

According to Pete Keillor :
On 13 Oct 2005 06:24:06 GMT, (DoN. Nichols)
wrote:

According to william_b_noble :

[ ... ]

you may find that a VFD costs about the same as a static converter (unless
you happen to have the parts and plan on building it yourself) - look for a
used one

Hmm ... a VFD is not likely to work well with a two-speed
three-phase motor -- unless you do all speed switching with the VFD.
You're not supposed to put the switch between the VFD and the motor, as
the voltage spikes from the switching can zap the output transistors of
the VFD.

[ ... ]

Rather than risk frying the old two speed motor on my TM mill, I got a
1 hp. Marathon inverter duty motor to go with the VFD. Good motors
aren't that expensive, or find a used one. The VFD handles generating
the low speed end well.

O.K. This is a reasonable approach, as long as the motor is not
mechanically unusual in its mounting, thus making the finding of a
replacement more difficult.

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 ---

On Wed, 12 Oct 2005 21:28:59 -0400, "JB" wrote:


"Jerry Martes" wrote in message
news:6Ai3f.21174$Tn5.14651@trnddc08...

"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase
converter?

Thanks in advance for the help.

Regards.

Joe...

Joe

I am pretty sure you would be content with the performance of a lathe at
home with a 5 HP 3 phase motor powered with single phase.
You probably wont be content with its performance if you intend to run it
loaded over about 4 HP for extended periods.
I'm impressed with the ability of a lathe like that being able to reverse
quite quickly.

Jerry


Jerry,

Thanks for the help. I don't think I'll be loading it up over 4 HP,
especially for long periods of time. My other concern is whether the two
speed motor will work with a static converter. Some say yes, some say no
and some say maybe.

Thanks again.

Joe...

Joe..save yourself some money and build a 7.5hp rotary converter. Even
rope start works very well for this application. You should be able
to find a good used motor for very little money (Id give you one if
you were closer), or simply add a pony motor and spin it up then apply
power to the big motor. Shrug..Im just about done with a 10hp pony
motor run PRC that runs even my big Clausing 1501 (7.5hp) in full
reverse/forwards applications, along with my big 3ph mig (though not
at the same time G)

You DONT need the bells and whistles of a self starter, unless you
absolutly want to.

Gunner

"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

On 13 Oct 2005 06:24:06 GMT, (DoN. Nichols)
wrote:

According to william_b_noble :

"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase converter?

you may find that a VFD costs about the same as a static converter (unless
you happen to have the parts and plan on building it yourself) - look for a
used one

Hmm ... a VFD is not likely to work well with a two-speed
three-phase motor -- unless you do all speed switching with the VFD.
You're not supposed to put the switch between the VFD and the motor, as
the voltage spikes from the switching can zap the output transistors of
the VFD.

Here is a place where I feel that a rotary converter
(build-it-yourself) would be the better choice. Or -- you could limit
yourself to one set of windings on the motor, and do all speed changing
with the VFD. For extreme cases (where you *really* need the higher
torque of the low speed, or the higher speed of the high speed), you can
stop the motor entirely (using the VFD's controls), switch to the other
speed at the lathe's switches, and then start the motor back up with the
VFD.

Good Luck,
DoN.

Absoutly correct Don. Bad things MAY happen when switching the lathe
controls when operating via a VFD.

I pulled all my lathes off the several VFDs and run them all on a 5hp
RPC for this reason.

The sole exception is that 9-18 Rivett that I wound up with several
months ago. It has a two speed motor..but last weekend, for the first
time I pulled the tarps and shrink wrap off of it..and discovered the
damned thing is 480vts....(Im not happy camper with a certain
Vietnamese charector because of this)

I could stick in one of the very very expensive 2 speed Hardnge motors
I have on hand...but I can sell them for more than the lathe is
worth..so will likely put in a single speed 3ph motor and run it off a
VFD. Its only a second ops lathe..so its no big deal.


Gunner

"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

On Fri, 14 Oct 2005 18:33:19 GMT, xray
wrote:

On Fri, 14 Oct 2005 09:04:34 GMT, Gunner
wrote:

Absoutly correct Don. Bad things MAY happen when switching the lathe
controls when operating via a VFD.

I pulled all my lathes off the several VFDs and run them all on a 5hp
RPC for this reason.

I'm not sure I understand exactly how bad things might happen with a
VFD. Do you mean switching something like a dual-speed motor or some
other electrical control while it is being driven?

Correct. If for example..I were to use the onboard reversing
switch...it momentarily interupts the power from the vfd..then spikes
it badly when it makes up again. Some serious spikes.

Think of it as spiking the clutch on your vehicle..while doing "hole
shots".

Sooner or later something will bust. With luck..it will simply be a
universal joint..but it could be the differential or tranny.

Gunner

"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

Gunner,

Thanks again for the advice. I too wish I lived closer to you. I have
learned much from you already and I sincerely appreciate your effort in
helping me.

Joe..
"Gunner" wrote in message
...
On Wed, 12 Oct 2005 21:28:59 -0400, "JB" wrote:


"Jerry Martes" wrote in message
news:6Ai3f.21174$Tn5.14651@trnddc08...

"JB" wrote in message
...
Hi Guys,

Once again I am here with my hat in hand humbly requesting your
assistance. As some of you know, I am in the process of purchasing a
Colchester Circa 1960's MK 1 1/2 lathe. It has a two speed 5hp 3 phase
motor. Will I be able to run it successfully on a static phase
converter?

Thanks in advance for the help.

Regards.

Joe...

Joe

I am pretty sure you would be content with the performance of a lathe
at
home with a 5 HP 3 phase motor powered with single phase.
You probably wont be content with its performance if you intend to run
it
loaded over about 4 HP for extended periods.
I'm impressed with the ability of a lathe like that being able to
reverse
quite quickly.

Jerry


Jerry,

Thanks for the help. I don't think I'll be loading it up over 4 HP,
especially for long periods of time. My other concern is whether the two
speed motor will work with a static converter. Some say yes, some say no
and some say maybe.

Thanks again.

Joe...

Joe..save yourself some money and build a 7.5hp rotary converter. Even
rope start works very well for this application. You should be able
to find a good used motor for very little money (Id give you one if
you were closer), or simply add a pony motor and spin it up then apply
power to the big motor. Shrug..Im just about done with a 10hp pony
motor run PRC that runs even my big Clausing 1501 (7.5hp) in full
reverse/forwards applications, along with my big 3ph mig (though not
at the same time G)

You DONT need the bells and whistles of a self starter, unless you
absolutly want to.

Gunner

"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

On Sat, 15 Oct 2005 11:30:11 GMT, xray
wrote:

On Sat, 15 Oct 2005 10:43:48 GMT, Gunner Asch
wrote:

On Fri, 14 Oct 2005 18:33:19 GMT, xray
wrote:

On Fri, 14 Oct 2005 09:04:34 GMT, Gunner
wrote:

Absoutly correct Don. Bad things MAY happen when switching the lathe
controls when operating via a VFD.

I pulled all my lathes off the several VFDs and run them all on a 5hp
RPC for this reason.

I'm not sure I understand exactly how bad things might happen with a
VFD. Do you mean switching something like a dual-speed motor or some
other electrical control while it is being driven?

Correct. If for example..I were to use the onboard reversing
switch...it momentarily interupts the power from the vfd..then spikes
it badly when it makes up again. Some serious spikes.

Think of it as spiking the clutch on your vehicle..while doing "hole
shots".

Yep. Did that. Or torquing against the brakes on an automatic. Never
broke anything like that I can remember. Other ways... other stories...
mostly dumber.


Sooner or later something will bust. With luck..it will simply be a
universal joint..but it could be the differential or tranny.


Gotcha. Thanks.

Uhhhmm... but an RPC is better for not causing problems when you power
switch? Just thinking out loud. But I'm not worried yet.

Yes..because an RPC doesnt use delicate electronics. It uses the brute
force method.

After posting a couple weeks back about slowing my lathe, I ordered a
Hitachi VFD and found a motor, cheap and local. Amazing what a handful
of electronics can do these days. I had to read the book for a few days
to begin to understand what to think about setting and how I might want
to interface to it. Incredible configuration options in the VFD.

Need to go buy some wire this morning to hook up the motor, then I'll
try it on the ground for a while. I plan to bypass most of the existing
lathe electrics, so I think it will all be good and I should have new
things like jog too.

I'll probably resurrect the other thread after I get things going, or if
I find some uglies.

Use the existing lathe Switchs to operate the VFD. Virtually
everything is there already, though in some cases..if for example your
forward/reverse switch was a momentary and picked a relay..you may
have to replace it with a maintained version, though some VFDs have
momentary input options. They are actually an amazing contraption G
and the designers have gone to great lengths to make them as usable as
possible under just about any configuration you can imagine.
Well..the good ones anyways G. From machine tools to pumps, air
handling and motion control. And Neptune washing machines......

Gunner

"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