If anyone in here is motor savvy...

I have 2 motors, 0.6hp, 3 phase, 130V, 20,000 rpm (In case any of that
matters).
They appears brushless, in that I can't see any.

Near the back of the shaft there is what looks like a disc shaped magnet
aligned with a housing containing some sensors, I presume this is to
monitor the speed. Am I likely to be able to replace this? Cos i've bust
one like a clumsy **** while replacing a bearing.

On another motor I have successfully replaced a bearing but it's now a
fair bit noisier, I think I have warped the fan at the very back of the
shaft, it was held on by a roll pin and was a real pain in the arse to
get off.
I'm presuming I can get this balanced. Would this be done with the shaft
in or out?
Would any (or most) motor places be able to do this or is it a
specialised job? There is a local motor place but they'd tell me they
could do it if they couldn't and still try to charge.
And what sort of price?

Ta for any help.

On Mar 23, 4:46*pm, R D S wrote:
If anyone in here is motor savvy...

I have 2 motors, 0.6hp, 3 phase, 130V, 20,000 rpm (In case any of that
matters).
They appears brushless, in that I can't see any.

Near the back of the shaft there is what looks like a disc shaped magnet
aligned with a housing containing some sensors, I presume this is to
monitor the speed. Am I likely to be able to replace this? Cos i've bust
one like a clumsy **** while replacing a bearing.

On another motor I have successfully replaced a bearing but it's now a
fair bit noisier, I think I have warped the fan at the very back of the
shaft, it was held on by a roll pin and was a real pain in the arse to
get off.
I'm presuming I can get this balanced. Would this be done with the shaft
in or out?
Would any (or most) motor places be able to do this or is it a
specialised job? There is a local motor place but they'd tell me they
could do it if they couldn't and still try to charge.
And what sort of price?

Ta for any help.


Very likely its off an aircraft. They run at very high frequencies.
On balance if you are sure about the 20,000 rpm think aircraft
technology.
Not light aircraft where the technology is similar to automobiles but
the big jets
http://www.wonderquest.com/expoundin...al-systems.htm

Any motor running at that speed would not have a commutator,they are
very speed limited. (Centrifugal forces would destroy it.)

harry wrote:
Any motor running at that speed would not have a commutator,they are
very speed limited. (Centrifugal forces would destroy it.)


I've taken brushed motors up to 40K plus easily.

Its a matter of size as much as anything. Brush bounce is the limiting
factor on the ones I have done that on.


--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

On Mar 23, 9:24*pm, The Natural Philosopher
wrote:
harry wrote:
Any motor running at that speed would not have a commutator,they are
very speed limited. (Centrifugal forces would destroy it.)

I've taken brushed motors up to 40K plus easily.

Its a matter of size as much as anything. Brush bounce is the limiting
factor on the ones I have done that on.

--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.


Yes your toy aircraft motors.

On Fri, 23 Mar 2012 23:07:53 -0700, harry wrote:

On Mar 23, 9:24Â*pm, The Natural Philosopher
wrote:
harry wrote:
Any motor running at that speed would not have a commutator,they are
very speed limited. (Centrifugal forces would destroy it.)

I've taken brushed motors up to 40K plus easily.

Its a matter of size as much as anything. Brush bounce is the limiting
factor on the ones I have done that on.

--
To people who know nothing, anything is possible. To people who know
too much, it is a sad fact that they know how little is really possible
- and how hard it is to achieve it.


Yes your toy aircraft motors.

And? You said 'Any motor'...



--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

*lightning protection* - a w_tom conductor

On 23/03/2012 18:09, harry wrote:
Any motor running at that speed would not have a commutator,they are
very speed limited. (Centrifugal forces would destroy it.)

Nonsense - plenty of small universal motors run at well over 10 krpm -
vacuum cleaners, drills, angle grinders... [etc.]

OTOH a 20 krpm 3-phase motor is something else. I thought aircraft
systems are usually 400 Hz, which would give synchronous speeds of 24000
rpm if 2-pole, 12000 rpm for 4-pole, etc. We need a photo (or
transcription) of the rating plate, really. It might run (slowly) on 50
Hz, but reduce the applied voltage in proportion to the frequency,
otherwise there will be smoke.

--
Andy

In article
,
harry wrote:
Any motor running at that speed would not have a commutator,they are
very speed limited. (Centrifugal forces would destroy it.)

Don't be silly. That's the actual motor speed of many a mains power tool.

--
*Reality? Is that where the pizza delivery guy comes from?

Dave Plowman London SW
To e-mail, change noise into sound.

On Mar 24, 5:18*pm, "Dave Plowman (News)"
wrote:
In article
,
* *harry wrote:

Any motor running at that speed would not have a commutator,they are
very speed limited. (Centrifugal forces would destroy it.)

Don't be silly. That's the actual motor speed of many a mains power tool.

--
*Reality? *Is that where the pizza delivery guy comes from?

* * Dave Plowman * * * * * * * * London SW
* * * * * * * * * To e-mail, change noise into sound.

So have you actually measured one to 20,000rpm or is it an urban myth?

In article
,
harry wrote:
Don't be silly. That's the actual motor speed of many a mains power
tool.


So have you actually measured one to 20,000rpm or is it an urban myth?

It's stated on the label of many.

--
*Ever stop to think and forget to start again?

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article
,
harry wrote:
Don't be silly. That's the actual motor speed of many a mains power
tool.


So have you actually measured one to 20,000rpm or is it an urban myth?

It's stated on the label of many.

planers for example.

Bill

In article ,
Martin wrote:
"Bosch GBM 6RE 350w Professional Rotary Drill 230v GBM6RE

Very high speed (no-load speed: 4000 rpm) for small drilling
diameters."

That's the chuck speed. Motor speed likely far higher.

--
*The problem with the world is that everyone is a few drinks behind *

Dave Plowman London SW
To e-mail, change noise into sound.

On 24/03/2012 23:37, Dave Plowman (News) wrote:
In ,
wrote:
"Bosch GBM 6RE 350w Professional Rotary Drill 230v GBM6RE

Very high speed (no-load speed: 4000 rpm) for small drilling
diameters."

That's the chuck speed. Motor speed likely far higher.

My small Bosch router runs 33K rpm


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 23/03/12 16:46, R D S wrote:
If anyone in here is motor savvy...

I have 2 motors, 0.6hp, 3 phase, 130V, 20,000 rpm (In case any of that
matters).
They appears brushless, in that I can't see any.


Some pics,
http://basecurve.co.uk/temp/DSCF1245.JPG
http://basecurve.co.uk/temp/DSCF1247.JPG
http://basecurve.co.uk/temp/DSCF1248.JPG

The magnet near the right side of the shaft in the second picture is the
bit that I have knocked a chunk out of, it sits in the part in pic 3
when assembled.

"R D S" wrote in message
...
On 23/03/12 16:46, R D S wrote:
If anyone in here is motor savvy...

I have 2 motors, 0.6hp, 3 phase, 130V, 20,000 rpm (In case any of that
matters).
They appears brushless, in that I can't see any.


Some pics,
http://basecurve.co.uk/temp/DSCF1245.JPG
http://basecurve.co.uk/temp/DSCF1247.JPG
http://basecurve.co.uk/temp/DSCF1248.JPG

The magnet near the right side of the shaft in the second picture is the
bit that I have knocked a chunk out of, it sits in the part in pic 3 when
assembled.

I'd have called it an induction motor but here -
http://parts.gesrepair.com/tblweb_pa..._detail/140004
they call it a servo motor.

On Mar 24, 4:16*pm, "brass monkey" wrote:
"R D S" wrote in ...





On 23/03/12 16:46, R D S wrote:
If anyone in here is motor savvy...

I have 2 motors, 0.6hp, 3 phase, 130V, 20,000 rpm (In case any of that
matters).
They appears brushless, in that I can't see any.

Some pics,
http://basecurve.co.uk/temp/DSCF1245.JPG
http://basecurve.co.uk/temp/DSCF1247.JPG
http://basecurve.co.uk/temp/DSCF1248.JPG

The magnet near the right side of the shaft in the second picture is the
bit that I have knocked a chunk out of, it sits in the part in pic 3 when
assembled.

I'd have called it an induction motor but here -http://parts.gesrepair.com/tblweb_part/show_part_detail/140004
they call it a servo motor.-

Well it canbe both so you are probably tright. Servo motor describes
it's function, not the operating principle.
Lots of servo motors on aircraft.

I don't see that it will be of any use to you, it is a very
specialised function and operating environment.
Probably intended to open a valve or operate a lock or something like
that.

On 24/03/2012 16:16, brass monkey wrote:

I'd have called it an induction motor but here -
http://parts.gesrepair.com/tblweb_pa..._detail/140004
they call it a servo motor.

It's certainly a brushless DC motor of some flavour. These might help:

http://en.wikipedia.org/wiki/Brushle...electric_motor
http://www.bodine-electric.com/

--
Andy

On Mar 23, 4:46*pm, R D S wrote:
If anyone in here is motor savvy...

I have 2 motors, 0.6hp, 3 phase, 130V, 20,000 rpm (In case any of that
matters).
They appears brushless, in that I can't see any.

Near the back of the shaft there is what looks like a disc shaped magnet
aligned with a housing containing some sensors, I presume this is to
monitor the speed. Am I likely to be able to replace this? Cos i've bust
one like a clumsy **** while replacing a bearing.

On another motor I have successfully replaced a bearing but it's now a
fair bit noisier, I think I have warped the fan at the very back of the
shaft, it was held on by a roll pin and was a real pain in the arse to
get off.
I'm presuming I can get this balanced. Would this be done with the shaft
in or out?
Would any (or most) motor places be able to do this or is it a
specialised job? There is a local motor place but they'd tell me they
could do it if they couldn't and still try to charge.
And what sort of price?

Ta for any help.


Also found this
http://en.wikipedia.org/wiki/Brushle...electric_motor
May have a bearing on the matter