Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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Old January 23rd 21, 02:52 AM posted to rec.crafts.metalworking
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Default Motor question

It's an old motor , 3/4 hp . And it's a universal motor , with a flat
disc commutator and brushes that can be rotated to reverse motor
rotation . I was looking at it today and saw on the tag that it can be
operated on 110 or 220 volts ... Currently it's wired with the armature
and field windings in parallel , I believe that's called shunt . I was
operating it on 110 volts on my lathe (until I got a smaller unit , this
thing is huge) . I have a project that I might use it on , but I'd like
to go 220V . Am I correct in assuming that hooking the windings in
series will convert it to 220 ? Since this motor is a universal motor ,
is it speed controllable by varying the voltage ?
--
Snag
Illegitimi non
carborundum

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Old January 23rd 21, 02:51 PM posted to rec.crafts.metalworking
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Default Motor question

On Friday, January 22, 2021 at 8:52:32 PM UTC-5, Snag wrote:
It's an old motor , 3/4 hp . And it's a universal motor , with a flat
disc commutator and brushes that can be rotated to reverse motor
rotation . I was looking at it today and saw on the tag that it can be
operated on 110 or 220 volts ... Currently it's wired with the armature
and field windings in parallel , I believe that's called shunt . I was
operating it on 110 volts on my lathe (until I got a smaller unit , this
thing is huge) . I have a project that I might use it on , but I'd like
to go 220V . Am I correct in assuming that hooking the windings in
series will convert it to 220 ? Since this motor is a universal motor ,
is it speed controllable by varying the voltage ?
--
Snag
Illegitimi non
carborundum


I am not a expert on motors or even reasonably knowledgeable about motors. But it seems to me that if the field and armature are in series and the voltage is close to being the same for the field and armature then it should be fine for 220 volts . And you should be able to check whether the voltages are roughly equal with 110 or 220 applied. And if you apply 110 volts with the field and armature in series, it should be obvious that the speed is controllable by varying the voltage.

Dan
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Old January 23rd 21, 03:31 PM posted to rec.crafts.metalworking
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Posts: 307
Default Motor question

On 23/01/2021 01:52, Snag wrote:
* It's an old motor , 3/4 hp . And it's a universal motor , with a
flat disc commutator and brushes that can be rotated to reverse motor
rotation . I was looking at it today and saw on the tag that it can be
operated on 110 or 220 volts ... Currently it's wired with the
armature and field windings in parallel , I believe that's called
shunt . I was operating it on 110 volts on my lathe (until I got a
smaller unit , this thing is huge) . I have a project that I might use
it on , but I'd like to go 220V . Am I correct in assuming that
hooking the windings in series will convert it to 220 ? Since this
motor is a universal motor , is it speed controllable by varying the
voltage ?


It may not be a universal motor but rather an repulsion motor
https://en.wikipedia.org/wiki/Repulsion_motor , possibly a repulsion
start induction run variant. I have a 1hp one on a compressor and the
commutator segments move once up to speed to take them out of the
circuit and like yours the brush position can be changed to alter the
starting torque and direction.

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Old January 23rd 21, 06:26 PM posted to rec.crafts.metalworking
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Default Motor question

On 1/22/2021 8:52 PM, Snag wrote:
... Am I correct in assuming that hooking the windings in
series will convert it to 220 ? ...



I think that is a very poor assumption. There are series-wound motors
and they're very different animals, in that the high armature current
also flows through the field. In a shunt-wound motor a much smaller
current flows through the field. In a shunt wound the field current is
independent of the load and the armature current varies with load.

If you try it, be sure to get a video for us 😊
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Old January 24th 21, 07:06 AM posted to rec.crafts.metalworking
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Default Motor question

On Sat, 23 Jan 2021 05:51:09 -0800 (PST), "
wrote:

On Friday, January 22, 2021 at 8:52:32 PM UTC-5, Snag wrote:
It's an old motor , 3/4 hp . And it's a universal motor , with a flat
disc commutator and brushes that can be rotated to reverse motor
rotation . I was looking at it today and saw on the tag that it can be
operated on 110 or 220 volts ... Currently it's wired with the armature
and field windings in parallel , I believe that's called shunt . I was
operating it on 110 volts on my lathe (until I got a smaller unit , this
thing is huge) . I have a project that I might use it on , but I'd like
to go 220V . Am I correct in assuming that hooking the windings in
series will convert it to 220 ? Since this motor is a universal motor ,
is it speed controllable by varying the voltage ?
--
Snag
Illegitimi non
carborundum


I am not a expert on motors or even reasonably knowledgeable about motors. But it seems to me that if the field and armature are in series and the voltage is close to being the same for the field and armature then it should be fine for 220 volts . And you should be able to check whether the voltages are roughly equal with 110 or 220 applied. And if you apply 110 volts with the field and armature in series, it should be obvious that the speed is controllable by varying the voltage.

Dan

A series wound motor has no "speed" contril - it ha torque control and
it has infinite torge at zero RPM, going to zero torque at infinite
RPM - in theory. When the counter EMF reaches the supply voltage the
torque is zero. There is no speed "regulation" - it slows sown with
load - USELESS for a machine tool.

A shuint motor has very strong speed regulation
To control series motor speed requires a feedback loop to control the
voltage in response to speed (inverse to load)


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Old January 28th 21, 03:14 PM posted to rec.crafts.metalworking
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Default Motor question

On Friday, January 22, 2021 at 8:52:32 PM UTC-5, Snag wrote:
Am I correct in assuming that hooking the windings in
series will convert it to 220 ?


If you replace the neutral with a second ungrounded conductor.

Since this motor is a universal motor , is it speed controllable by varying the voltage ?


Hook up a $15 or $20 dollar AC 110-220V 10000W SCR Motor Speed Controller Volt Regulator to make sure.
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Old January 29th 21, 10:31 PM posted to rec.crafts.metalworking
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Posts: 307
Default Motor question

On 23/01/2021 14:31, David Billington wrote:
On 23/01/2021 01:52, Snag wrote:
* It's an old motor , 3/4 hp . And it's a universal motor , with a
flat disc commutator and brushes that can be rotated to reverse motor
rotation . I was looking at it today and saw on the tag that it can
be operated on 110 or 220 volts ... Currently it's wired with the
armature and field windings in parallel , I believe that's called
shunt . I was operating it on 110 volts on my lathe (until I got a
smaller unit , this thing is huge) . I have a project that I might
use it on , but I'd like to go 220V . Am I correct in assuming that
hooking the windings in series will convert it to 220 ? Since this
motor is a universal motor , is it speed controllable by varying the
voltage ?


It may not be a universal motor but rather an repulsion motor
https://en.wikipedia.org/wiki/Repulsion_motor , possibly a repulsion
start induction run variant. I have a 1hp one on a compressor and the
commutator segments move once up to speed to take them out of the
circuit and like yours the brush position can be changed to alter the
starting torque and direction.

If this is a repulsion motor then there is no connection of the brushes
to the mains they simply serve to short the rotor. That would seem to
leave the need for 2 field windings for dual voltage operation them
being wired in parallel for 110V operation and in series for 220V. In my
repulsion start induction run motor the action of the commutator segment
moving when the motor runs up to speed is quite obvious with the brush
access cover removed. Access to some images would help to comment further.

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Old January 31st 21, 05:51 AM posted to rec.crafts.metalworking
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Posts: 199
Default Motor question

On 1/24/2021 12:06 AM, Clare Snyder wrote:
On Sat, 23 Jan 2021 05:51:09 -0800 (PST), "
wrote:

On Friday, January 22, 2021 at 8:52:32 PM UTC-5, Snag wrote:
It's an old motor , 3/4 hp . And it's a universal motor , with a flat
disc commutator and brushes that can be rotated to reverse motor
rotation . I was looking at it today and saw on the tag that it can be
operated on 110 or 220 volts ... Currently it's wired with the armature
and field windings in parallel , I believe that's called shunt . I was
operating it on 110 volts on my lathe (until I got a smaller unit , this
thing is huge) . I have a project that I might use it on , but I'd like
to go 220V . Am I correct in assuming that hooking the windings in
series will convert it to 220 ? Since this motor is a universal motor ,
is it speed controllable by varying the voltage ?
--
Snag
Illegitimi non
carborundum


I am not a expert on motors or even reasonably knowledgeable about motors. But it seems to me that if the field and armature are in series and the voltage is close to being the same for the field and armature then it should be fine for 220 volts . And you should be able to check whether the voltages are roughly equal with 110 or 220 applied. And if you apply 110 volts with the field and armature in series, it should be obvious that the speed is controllable by varying the voltage.

Dan

A series wound motor has no "speed" contril - it ha torque control and
it has infinite torge at zero RPM, going to zero torque at infinite
RPM - in theory. When the counter EMF reaches the supply voltage the
torque is zero. There is no speed "regulation" - it slows sown with
load - USELESS for a machine tool.

A shuint motor has very strong speed regulation
To control series motor speed requires a feedback loop to control the
voltage in response to speed (inverse to load)


OK , this verifies something I thought I remembered from when I was a
boy about series motors . I was considering using this motor to power a
5" jointer/planer partly because it's size would anchor the base with
it's mass . The last thing I need is a runaway jointer ... so if I do
use it I'll be leaving it hooked shunt and on 110V .
--
Snag
Illegitimi non
carborundum
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Old January 31st 21, 05:56 AM posted to rec.crafts.metalworking
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Posts: 199
Default Motor question

On 1/29/2021 3:31 PM, David Billington wrote:
On 23/01/2021 14:31, David Billington wrote:
On 23/01/2021 01:52, Snag wrote:
* It's an old motor , 3/4 hp . And it's a universal motor , with a
flat disc commutator and brushes that can be rotated to reverse motor
rotation . I was looking at it today and saw on the tag that it can
be operated on 110 or 220 volts ... Currently it's wired with the
armature and field windings in parallel , I believe that's called
shunt . I was operating it on 110 volts on my lathe (until I got a
smaller unit , this thing is huge) . I have a project that I might
use it on , but I'd like to go 220V . Am I correct in assuming that
hooking the windings in series will convert it to 220 ? Since this
motor is a universal motor , is it speed controllable by varying the
voltage ?


It may not be a universal motor but rather an repulsion motor
https://en.wikipedia.org/wiki/Repulsion_motor , possibly a repulsion
start induction run variant. I have a 1hp one on a compressor and the
commutator segments move once up to speed to take them out of the
circuit and like yours the brush position can be changed to alter the
starting torque and direction.

If this is a repulsion motor then there is no connection of the brushes
to the mains they simply serve to short the rotor. That would seem to
leave the need for 2 field windings for dual voltage operation them
being wired in parallel for 110V operation and in series for 220V. In my
repulsion start induction run motor the action of the commutator segment
moving when the motor runs up to speed is quite obvious with the brush
access cover removed. Access to some images would help to comment further.


You may be right , I'll have to check it out and see if the
commutator pulls back or , more likely , the brush assembly pulls away
from it . I used this monster for a short time on my Logan/PowrKraft
lathe , but never paid much attention to what was going on inside the
end bell .
--
Snag
Illegitimi non
carborundum
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Old January 31st 21, 09:00 PM posted to rec.crafts.metalworking
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First recorded activity by DIYBanter: Oct 2007
Posts: 398
Default Motor question

On Sat, 30 Jan 2021 22:51:34 -0600, Snag wrote:

On 1/24/2021 12:06 AM, Clare Snyder wrote:
On Sat, 23 Jan 2021 05:51:09 -0800 (PST), "
wrote:

On Friday, January 22, 2021 at 8:52:32 PM UTC-5, Snag wrote:
It's an old motor , 3/4 hp . And it's a universal motor , with a flat
disc commutator and brushes that can be rotated to reverse motor
rotation . I was looking at it today and saw on the tag that it can be
operated on 110 or 220 volts ... Currently it's wired with the armature
and field windings in parallel , I believe that's called shunt . I was
operating it on 110 volts on my lathe (until I got a smaller unit , this
thing is huge) . I have a project that I might use it on , but I'd like
to go 220V . Am I correct in assuming that hooking the windings in
series will convert it to 220 ? Since this motor is a universal motor ,
is it speed controllable by varying the voltage ?
--
Snag
Illegitimi non
carborundum

I am not a expert on motors or even reasonably knowledgeable about motors. But it seems to me that if the field and armature are in series and the voltage is close to being the same for the field and armature then it should be fine for 220 volts . And you should be able to check whether the voltages are roughly equal with 110 or 220 applied. And if you apply 110 volts with the field and armature in series, it should be obvious that the speed is controllable by varying the voltage.

Dan

A series wound motor has no "speed" contril - it ha torque control and
it has infinite torge at zero RPM, going to zero torque at infinite
RPM - in theory. When the counter EMF reaches the supply voltage the
torque is zero. There is no speed "regulation" - it slows sown with
load - USELESS for a machine tool.

A shuint motor has very strong speed regulation
To control series motor speed requires a feedback loop to control the
voltage in response to speed (inverse to load)


OK , this verifies something I thought I remembered from when I was a
boy about series motors . I was considering using this motor to power a
5" jointer/planer partly because it's size would anchor the base with
it's mass . The last thing I need is a runaway jointer ... so if I do
use it I'll be leaving it hooked shunt and on 110V .


Unloaded series-connected universal motors have no upper speed limit,
at least in theory.

A runaway is likely to overspeed the jointer knife assembly, which may
proceed to burst from centrifugal force - this would be dangerous to
man and machine.

Joe Gwinn


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