Hi all,
I know very little to nothing about motors. I am looking to get a
motor to help improve my grain mill (I'm a homebrewer).

What I know I need is this:
1750 rpm

I'll be running shome sheaves to tone that down to about 185 rpm. The
specs I've read used a 1/3 HP motor. If i understand it right, slowing
the rpms will increase torque. I'm not sure how much lee way I have
with the HP, I need enough torque to crush the barley without making
it flour.

In the plans to plug this thing into a wall receptical, I'd assume I
want 120V. I would think you can wire a 230V to plug into a 110V (or
is it 120V) wall outlet. I've seen all kinds of voltage from 90 to
above 240. What range should I look in for plugging into the wall?
What about Hz, I know what the measurement of Hz is, but have no idea
how it relates to motors? What the heck is a 2-phase or 3-phase motor?
Should that mean anything to me? What about AC vs DC? I'd assume I
want an AC motor, but could I wire a DC to plug into the wall?

Thanks,
Mike

On Jan 17, 9:34=A0pm, MikeC <downpantera101pr...@yahoo.com> wrote:
> Hi all,
> I know very little to nothing about motors. I am looking to get a
> motor to help improve my grain mill (I'm a homebrewer).
>
> What I know I need is this:
> 1750 rpm
>
> I'll be running shome sheaves to tone that down to about 185 rpm. The
> specs I've read used a 1/3 HP motor. If i understand it right, slowing
> the rpms will increase torque. I'm not sure how much lee way I have
> with the HP, I need enough torque to crush the barley without making
> it flour.
>
> In the plans to plug this thing into a wall receptical, I'd assume I
> want 120V. I would think you can wire a 230V to plug into a 110V (or
> is it 120V) wall outlet. I've seen all kinds of voltage from 90 to
> above 240. What range should I look in for plugging into the wall?
> What about Hz, I know what the measurement of Hz is, but have no idea
> how it relates to motors? What the heck is a 2-phase or 3-phase motor?
> Should that mean anything to me? What about AC vs DC? I'd assume I
> want an AC motor, but could I wire a DC to plug into the wall?
>
> Thanks,
> Mike

if it 3 phase your home power will not work, thats big power and you
do not want to mess with that it's a killer, you cannot plug a 230v
into a 120 not enough power you will burn up your moter, you need to
know excact power neede dfor the moter, did the mortor come with a
plug? if it did dose it look like a regular plug? your best thing is
to get a electrition, to wire it up for you so you dont burn somthing
up like your motor or evan your house

On Thu, 17 Jan 2008 21:34:10 -0800, MikeC wrote:

> Hi all,
> I know very little to nothing about motors. I am looking to get a motor
> to help improve my grain mill (I'm a homebrewer).
>
> What I know I need is this:
> 1750 rpm
>
> I'll be running shome sheaves to tone that down to about 185 rpm. The
> specs I've read used a 1/3 HP motor. If i understand it right, slowing
> the rpms will increase torque. I'm not sure how much lee way I have with
> the HP, I need enough torque to crush the barley without making it
> flour.
>
> In the plans to plug this thing into a wall receptical, I'd assume I
> want 120V. I would think you can wire a 230V to plug into a 110V (or is
> it 120V) wall outlet. I've seen all kinds of voltage from 90 to above
> 240. What range should I look in for plugging into the wall? What about
> Hz, I know what the measurement of Hz is, but have no idea how it
> relates to motors? What the heck is a 2-phase or 3-phase motor? Should
> that mean anything to me? What about AC vs DC? I'd assume I want an AC
> motor, but could I wire a DC to plug into the wall?
>
> Thanks,
> Mike

Oy. You have a learning curve ahead of you. Please don't come crying to
me if you accidentally grind up your hand.

Gearing down the motor with belts or whatnot will, indeed increase torque
as the speed goes down. You don't lose all that much power when you gear
down, and power = speed * torque, so less speed = more torque.

To plug it into the wall, you need a single phase AC motor. If you are
currently turning the crank by hand you're probably doing about 1/20 to
1/5 (if you're Conan) horsepower. If you run the mill at the same speed
as you're hand cranking it you could probably get away with an even
smaller motor, should you be able to find one.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

"MikeC" <downpantera101proof@yahoo.com> wrote in message
news:b08adde5-9e38-4f98-b4a4-924203f1b596@e23g2000prf.googlegroups.com...
> Hi all,
> I know very little to nothing about motors. I am looking to get a
> motor to help improve my grain mill (I'm a homebrewer).
>
> What I know I need is this:
> 1750 rpm

That is a typical speed for a 4 pole AC induction motor running off of 60 hz.
A 2 pole AC induction motor typically runs about twice that speed.
Based upon this info, most of the remaining discussion will be focused
on AC induction motors.


> I'll be running shome sheaves to tone that down to about 185 rpm.

"shome sheaves" ??? That is a new term to me.


>
> The
> specs I've read used a 1/3 HP motor. If i understand it right, slowing
> the rpms will increase torque.

In general, with gears, reducing speed will increase the torque.


> I'm not sure how much lee way I have
> with the HP, I need enough torque to crush the barley without making
> it flour.

Sorry, I have no idea about the requirements for crushing barley.


> In the plans to plug this thing into a wall receptical, I'd assume I
> want 120V. I would think you can wire a 230V to plug into a 110V (or
> is it 120V) wall outlet. I've seen all kinds of voltage from 90 to
> above 240. What range should I look in for plugging into the wall?

That depends upon where you are located. In the US, a wall outlet supplies
120 V at 60 Hz. In Europe, 240 V at 50 Hz is common (or so I have read).

You probably want to select a motor with whose voltage and frequency match
what you have available at your location. Some motors can be wired to
operate using either 240 or 120 volts. Warning: You should not try to use
a 120 V motor on 240 V. Likewise there can be problems running a 60 Hz
motor on 50Hz.


> What about Hz, I know what the measurement of Hz is, but have no idea
> how it relates to motors?

The speed of an AC induction motor depends upon the input frequency and
the number of poles inside the motor. From your desired speed of 1750 rpm,
this implies that you will want a 4 pole motor powered by 60 Hz. A 4 pole
motor will run at about 1450 rpm if you run it off of 50 Hz. A 2 pole motor
running on 60 Hz will typically run about 3500 rpm.

There are variable speed motor controllers that you can buy that will supply
a variable frequency to drive a motor at different speeds.

> What the heck is a 2-phase or 3-phase motor?

In your power range (1/3 HP), a single phase motor is probably what you
want. A 3 phase motor is typically used for higher power applications.
A 3 phase motor requires 3 phase power. That can be a problem in the
US since most homes are not provided with 3 phase power.


> Should that mean anything to me? What about AC vs DC? I'd assume I
> want an AC motor, but could I wire a DC to plug into the wall?

There are several different types (and subtypes) of motors. They each
have their advantages and disadvantages. The right type depends upon
thing like the need for: constant speed?, variable speed? constant torque?
variable torque?, power?, size?, reliability?, cost, etc.

More information about motors can be found on the web. For example:
http://en.wikipedia.org/wiki/Electric_motor

"Dan Coby" <adcoby@earthlink.net> wrote in
news:13p0nhbpbn259ff@corp.supernews.com:

>
>"MikeC" <downpantera101proof@yahoo.com> wrote in message
>news:b08adde5-9e38-4f98-b4a4-924203f1b596@e23g2000prf.googlegroups.com..
>.
>> Hi all,
>> I know very little to nothing about motors. I am looking to get a
>> motor to help improve my grain mill (I'm a homebrewer).
>>
>> What I know I need is this:
>> 1750 rpm
>
>That is a typical speed for a 4 pole AC induction motor running off of
>60 hz. A 2 pole AC induction motor typically runs about twice that
>speed. Based upon this info, most of the remaining discussion will be
>focused on AC induction motors.
>
>
>> I'll be running shome sheaves to tone that down to about 185 rpm.
>
>"shome sheaves" ??? That is a new term to me.
>
>
>>
>> The
>> specs I've read used a 1/3 HP motor. If i understand it right,
>> slowing the rpms will increase torque.
>
>In general, with gears, reducing speed will increase the torque.
>
>
>> I'm not sure how
>> much lee way I have
>> with the HP, I need enough torque to crush the barley without making
>> it flour.
>
>Sorry, I have no idea about the requirements for crushing barley.
>
>
>> In the plans to plug this thing into a wall receptical, I'd assume I
>> want 120V. I would think you can wire a 230V to plug into a 110V (or
>> is it 120V) wall outlet. I've seen all kinds of voltage from 90 to
>> above 240. What range should I look in for plugging into the wall?
>
>That depends upon where you are located. In the US, a wall outlet
>supplies 120 V at 60 Hz. In Europe, 240 V at 50 Hz is common (or so I
>have read).
>
>You probably want to select a motor with whose voltage and frequency
>match what you have available at your location. Some motors can be
>wired to operate using either 240 or 120 volts. Warning: You should not
>try to use a 120 V motor on 240 V. Likewise there can be problems
>running a 60 Hz motor on 50Hz.
>
>
>> What about Hz, I know what the measurement of Hz is, but have no idea
>> how it relates to motors?
>
>The speed of an AC induction motor depends upon the input frequency and
>the number of poles inside the motor. From your desired speed of 1750
>rpm, this implies that you will want a 4 pole motor powered by 60 Hz.
>A 4 pole motor will run at about 1450 rpm if you run it off of 50 Hz.
>A 2 pole motor running on 60 Hz will typically run about 3500 rpm.
>
>There are variable speed motor controllers that you can buy that will
>supply a variable frequency to drive a motor at different speeds.
>
>> What the heck is a
>> 2-phase or 3-phase motor?
>
>In your power range (1/3 HP), a single phase motor is probably what you
>want. A 3 phase motor is typically used for higher power applications.
>A 3 phase motor requires 3 phase power. That can be a problem in the
>US since most homes are not provided with 3 phase power.
>
>
>> Should that mean anything to me? What about AC vs DC? I'd assume I
>> want an AC motor, but could I wire a DC to plug into the wall?
>
>There are several different types (and subtypes) of motors. They each
>have their advantages and disadvantages. The right type depends upon
>thing like the need for: constant speed?, variable speed? constant
>torque? variable torque?, power?, size?, reliability?, cost, etc.
>
>More information about motors can be found on the web. For example:
>http://en.wikipedia.org/wiki/Electric_motor
>
>
>

A good place to start is an old washing machine. They typically have a
1/2 HP motor that runs about 1725 rpm you can also drill out the welds
and get the motor mount with it...

"MikeC" <downpantera101proof@yahoo.com> wrote in message
news:b08adde5-9e38-4f98-b4a4-924203f1b596@e23g2000prf.googlegroups.com...
> Hi all,
> I know very little to nothing about motors. I am looking to get a
> motor to help improve my grain mill (I'm a homebrewer).
>
> What I know I need is this:
> 1750 rpm
>
> I'll be running shome sheaves to tone that down to about 185 rpm. The
> specs I've read used a 1/3 HP motor. If i understand it right, slowing
> the rpms will increase torque. I'm not sure how much lee way I have
> with the HP, I need enough torque to crush the barley without making
> it flour.
>
> In the plans to plug this thing into a wall receptical, I'd assume I
> want 120V. I would think you can wire a 230V to plug into a 110V (or
> is it 120V) wall outlet. I've seen all kinds of voltage from 90 to
> above 240. What range should I look in for plugging into the wall?
> What about Hz, I know what the measurement of Hz is, but have no idea
> how it relates to motors? What the heck is a 2-phase or 3-phase motor?
> Should that mean anything to me? What about AC vs DC? I'd assume I
> want an AC motor, but could I wire a DC to plug into the wall?
>
> Thanks,
> Mike

Go to Rec.Crafts.Brewing.
You will get plenty of help with your grain mill.

Tom

On Jan 18, 2:07=A0am, "Dan Coby" <adc...@earthlink.net> wrote:
> "MikeC" <downpantera101pr...@yahoo.com> wrote in message
>
> news:b08adde5-9e38-4f98-b4a4-924203f1b596@e23g2000prf.googlegroups.com...
>
> > Hi all,
> > I know very little to nothing about motors. I am looking to get a
> > motor to help improve my grain mill (I'm a homebrewer).
>
> > What I know I need is this:
> > 1750 rpm
>
> That is a typical speed for a 4 pole AC induction motor running off of 60 =
hz.
> A 2 pole AC induction motor typically runs about twice that speed.
> Based upon this info, most of the remaining discussion will be focused
> on AC induction motors.
>
> > I'll be running shome sheaves to tone that down to about 185 rpm.
>
> "shome sheaves" ??? =A0 That is a new term to me.
>
>
>
> > The
> > specs I've read used a 1/3 HP motor. If i understand it right, slowing
> > the rpms will increase torque.
>
> In general, with gears, reducing speed will increase the torque.
>
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0I'm not sure how much lee way I have
> > with the HP, I need enough torque to crush the barley without making
> > it flour.
>
> Sorry, I have no idea about the requirements for crushing barley.
>
> > In the plans to plug this thing into a wall receptical, I'd assume I
> > want 120V. I would think you can wire a 230V to plug into a 110V (or
> > is it 120V) wall outlet. I've seen all kinds of voltage from 90 to
> > above 240. What range should I look in for plugging into the wall?
>
> That depends upon where you are located. =A0In the US, a wall outlet suppl=
ies
> 120 V at 60 Hz. =A0In Europe, 240 V at 50 Hz is common (or so I have read)=
..
>
> You probably want to select a motor with whose voltage and frequency match=

> what you have available at your location. =A0Some motors can be wired to
> operate using either 240 or 120 volts. Warning: You should not try to use
> a 120 V motor on 240 V. Likewise there can be problems running a 60 Hz
> motor on 50Hz.
>
> > What about Hz, I know what the measurement of Hz is, but have no idea
> > how it relates to motors?
>
> The speed of an AC induction motor depends upon the input frequency and
> the number of poles inside the motor. From your desired speed of 1750 rpm,=

> this implies that you will want a 4 pole motor powered by 60 Hz. =A0A 4 po=
le
> motor will run at about 1450 rpm if you run it off of 50 Hz. =A0A 2 pole m=
otor
> running on 60 Hz will typically run about 3500 rpm.
>
> There are variable speed motor controllers that you can buy that will supp=
ly
> a variable frequency to drive a motor at different speeds.
>
> > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0What the heck is a 2-phase or 3-phase motor?
>
> In your power range (1/3 HP), a single phase motor is probably what you
> want. =A0A 3 phase motor is typically used for higher power applications.
> A 3 phase motor requires 3 phase power. That can be a problem in the
> US since most homes are not provided with 3 phase power.
>
> > Should that mean anything to me? What about AC vs DC? I'd assume I
> > want an AC motor, but could I wire a DC to plug into the wall?
>
> There are several different types (and subtypes) of motors. =A0They each
> have their advantages and disadvantages. =A0The right type depends upon
> thing like the need for: constant speed?, variable speed? constant torque?=

> variable torque?, power?, size?, reliability?, cost, etc.
>
> More information about motors can be found on the web. =A0For example:http=
://en.wikipedia.org/wiki/Electric_motor

Sheaves are pulleys, one 1.5" and one 10". I am after constant speed.
My mill should run at 185 - 200 rpm and not any higher. I do not want
any big fluctuations in the rpm's.

MikeC wrote:

> Hi all,
> I know very little to nothing about motors. I am looking to get a
> motor to help improve my grain mill (I'm a homebrewer).
>
> What I know I need is this:
> 1750 rpm
>
> I'll be running shome sheaves to tone that down to about 185 rpm. The
> specs I've read used a 1/3 HP motor. If i understand it right, slowing
> the rpms will increase torque. I'm not sure how much lee way I have
> with the HP, I need enough torque to crush the barley without making
> it flour.
>
> In the plans to plug this thing into a wall receptical, I'd assume I
> want 120V. I would think you can wire a 230V to plug into a 110V (or
> is it 120V) wall outlet. I've seen all kinds of voltage from 90 to
> above 240. What range should I look in for plugging into the wall?
> What about Hz, I know what the measurement of Hz is, but have no idea
> how it relates to motors? What the heck is a 2-phase or 3-phase motor?
> Should that mean anything to me? What about AC vs DC? I'd assume I
> want an AC motor, but could I wire a DC to plug into the wall?
>
> Thanks,
> Mike
to determine the HP (horse power) needed, you need a strain gauge to
meter the load..
A fish scale or something like that can give you a ball park figure
if you don't have a real kit to work with.
It's been a while since I have done this, I usually refer to a hand
book for this but this seems to pop to mind..

HP = 6.28 x RPMs x Foot-Lbs-at-one-RPM /33,000

basically the foot lbs is the tension you get when moving
the load for a full rotation at the rate of 1 minute.


I guess you can start there to determine the HP.
You would most likely need a single phase motor.
--
http://webpages.charter.net/jamie_5"

In article <363fab39-854f-416f-805e-6b150d7ff713@k2g2000hse.googlegroups.com>,
MikeC <downpantera101proof@yahoo.com> wrote:
>On Jan 18, 2:07 am, "Dan Coby" <adc...@earthlink.net> wrote:
>> "MikeC" <downpantera101pr...@yahoo.com> wrote in message
>> news:b08adde5-9e38-4f98-b4a4-924203f1b596@e23g2000prf.googlegroups.com...
>> > Hi all,
>> > I know very little to nothing about motors. I am looking to get a
>> > motor to help improve my grain mill (I'm a homebrewer).
>
>Sheaves are pulleys, one 1.5" and one 10". I am after constant speed.
>My mill should run at 185 - 200 rpm and not any higher. I do not want
>any big fluctuations in the rpm's.

It sounds like you want a run-of-the-mill induction motor. They
have a "natural" speed (their synchronous speed) and they slow down
a little under load, but not a whole lot, unless they stall of
course. They're also one of the most common kinds of 1-HP-or-less
AC electric motor and they're cheap and reliable.

Your mention of a 1750-RPM motor reinforces this: that's almost
certainly a motor with a natural synchronous speed of 1800 RPM (60 Hz power,
times 60 seconds-per-minute, divided by 2 because of the construction
of the motor) which slows to around 1750 RPM under load.

(The other really common kind of motor in that size is the universal
motor, which can run off AC or DC (hence the name); they slow down more
under load but they have plenty of torque even when stalled (unlike an
induction motor). Universal motors are the kind found in hand drills
and circular saws and such. But a universal motor doesn't have a natural
speed; it just runs as fast as it can.)

>> > Should that mean anything to me? What about AC vs DC? I'd assume I
>> > want an AC motor, but could I wire a DC to plug into the wall?

Induction motors are always AC, since they use the alternating-ness
of the current to set up a rotating magnetic field, which is
what drags the rotor around. Some devices can take either AC or DC,
but in general, don't feed AC to something expecting DC (or vice
versa): you'll burn something out.

You don't need a 3-phase motor. Those are generally for larger
industrial stuff. And you probably don't have 3-phase AC power available
anyway. In the US, your typical wall plug provides 115 V (more or less)
single-phase AC power, 60 Hz (exactly), and can provide at most 15-20 amps.

Don't worry about getting the horsepower exactly right. A more powerful
induction motor will still turn at its natural speed, it'll just have
more force available to mangle your fingers if they get caught in the
belt. An undersized induction motor will stall more easily.

There are a few sub-types of induction motor, having to do with how
they start up: split-phase, capacitor-start, and shaded-pole. I think
you don't want a shaded-pole motor. Either of the other two sorts should
work fine, but a split-phase motor is probably slightly cheaper and
maybe simpler (capacitor-start motors have more starting torque,
but I don't think you'd need that for a mill).

Finally, I recommend you put a circuit breaker in between the motor
and the plug (unless the motor has one built in), since electric
motors can draw a ton of current when they stall, and can quickly
overheat and burn out. You can look on the motor's nameplate to
figure out what amperage the circuit breaker should have. I'd
probably wire it up like this:

wall plug >---- box with switch and circuit breaker >---- motor and mill



(While writing this I found ths web page which will help you
interpret the stuff printed on a motor's nameplate:
http://ecmweb.com/mag/electric_understa ... ion_motor/ )

Another place to ask would be woodworking and metalworking craft groups.
People are always putting new/different motors into their shop tools
and I think the FAQs for those groups will include a lot of the same
kind of questions and concerns you have.


--
Wim Lewis <wiml@hhhh.org>, Seattle, WA, USA. PGP keyID 27F772C1