Hi Ron
Thankyou for correcting me on hall sensors. so with 12 magnets 9 coils  ratio =
6. am I right in thinking halls get fitted at 30deg intervals.

Many Thanks
Paul

--- In lrk-torquemax@yahoogroups.com, "ron_van_sommeren" <ron.van.sommeren@...>
wrote:
>
> Goedendag Paul and all,
>
>
> > I realise using LRK type winding cannot use hall sensors ...
> No problem, hall sensors can be used with _all_ winding diagrams.
>
> Vriendelijke groeten ;-) Ron van Sommeren
> near Nijmegen, the Netherlands
>

I am curious to learn from your collective experience what adhesives work best
to bond core laminations.  What adhesives have you used and what did you like
about them?

I am considering using loctite 290, which is a wicking thread locker with a
temperature rating of 150 C. I like the idea of using a wicking adheasive so
that I can stack the laminations, then just brush on a little adhesive along the
sides and let capillary action pull the adheasive into the core, then apply
pressure and let it set quickly (less than 20 minutes).  For me, assembly time
is a high priority, I would rather not have to apply adhesive to each layer of
the lamination, since I need to laminate 4000 pieces.

Have any of you had experience with wicking adhesives rather than having to
apply adhesive manually between each piece?

Goedendag Paul and all,


> I realise using LRK type winding cannot use hall sensors ...
No problem, hall sensors can be used with _all_ winding diagrams.

Vriendelijke groeten ;-) Ron van Sommeren
near Nijmegen, the Netherlands

Hi
Please can someone explain how to size magnets for Axial flux motor to give
desired toque. ie with 2 magnet disc & stator coils between, is there simple
formula.

Thanks Paul

Hand Dryers in Restrooms

hmmmm. Don't know if this is true, but it is something to think about.

Everyone in the cleaning industry has always been told that hand dryers
in restrooms are not sanitary, they spread germs and bacteria around.
I always thought that this just came from the paper companies because
they are loosing sales to the hand dryers. A couple of years ago, I
was working with a rep, and I noticed that after he washed his hands
and noticed that there were no paper towels, only a hand dryer he left
the restroom with wet hands. I asked him about it. He said that hand
dryers blow a lot of germs and bacteria around. He also told me to
take a look under the hand dryer next time I was in a restroom. There
is a filter underneath the hand dryer that is supposed to be cleaned on
a weekly basis. I looked at one and it looked like it hadn't been
cleaned in years. It had layers and layers of caked on
gunk (disgusting) . Since then I will not use hand dryers in
restrooms. Now this is where the story gets really interesting. The
schools and universities that have had the H1N1 (swine flue) outbreak
this year are being told by the health department that they have
to take out all of their hand dryers and replace them with towel
dispensers because the hand dryers are spreading disease. Please pass
this along so everyone knows not to use hand dryers.




[Non-text portions of this message have been removed]

Hi all
Have been reading this forum for many months with much interest. Have built
axial flux motor for testing. spec magnets 24 0ff 15x5x1mm (12 on each 70mm dia
disc), 9 coils 5mm wide, 180 turns 0.25mm copper wire, air gap 0.5mm. Very
pleased with results. 12v, 9A stall, no load 4600RPM, would like to understand
how to design for high toque low RPM possibly max  1000RPM. This is for direct
drive to ball screw for CNC type  mc. I realise using LRK type winding cannot
use hall sensors but hope to use encoder & look up table in pic chip or similar.
Any clue re size magnets & toque ratio.

Many Thanks
Paul

Those low kv, <50W motors make great slow flier motors. ..hour long flights, and
enough power to carry a payload on 2000mAh 2 or 3 cell packs.

pete b

To: lrk-torquemax@yahoogroups.com
From: rick-page@...
Date: Wed, 2 Dec 2009 04:02:47 +0000
Subject: [lrk] Re: Low kV Small Motors




























       > So "higher voltage" should always be chosen if possible?

>(Power lost = I^2 * R)

Fewer cells are easier to manage for charging and pack building and at low
currents i^2r is negligible. As current increases, only then do the hassles of
high voltage packs become worthwhile. A 6 cell 50 mah pack would have more
weight in balancing taps than in the battery itself.



The 7-cell NiCd pack and a Speed 400 motor made electric flight accessible to
the masses and the 2 or 3-cell LiPo for <50W airplanes is in that niche now.



Rick.


















_________________________________________________________________
Chat with Messenger straight from your Hotmail inbox.
http://www.microsoft.com/windows/windowslive/hotmail_bl1/hotmail_bl1.aspx?ocid=P\
ID23879::T:WLMTAGL:ON:WL:en-ww:WM_IMHM_4:092009

[Non-text portions of this message have been removed]

> So "higher voltage" should always be chosen if possible?
>(Power lost = I^2 * R)
Fewer cells are easier to manage for charging and pack building and at low
currents i^2r is negligible. As current increases, only then do the hassles of
high voltage packs become worthwhile. A 6 cell 50 mah pack would have more
weight in balancing taps than in the battery itself.

The 7-cell NiCd pack and a Speed 400 motor made electric flight accessible to
the masses and the 2 or 3-cell LiPo for <50W airplanes is in that niche now.

Rick.

Talking about high voltage battery packs.
http://www.hightechsystemsllc.com/pt_Batterypacks.html

   ManuLRK
>>Why are there so few small outrunners (30 to 100watts)
>>that have low kVs (700 to 900)?
>Most really small motors only use 1-3 cells to save weight so the kV
has to be higher to get useful rpm's. Currents are low at these sizes
but as motors get larger it is better to increase voltage and decrease
kV.
>Rick.
Single cell Lipo battery capacities are available from a few 100th mAh
to 1000th (10.000 ?) mAh ., weight should not be a reason why small
motors can't be run on higher voltages!?
So "higher voltage" should always be chosen if possible? (Power lost =
I^2 * R)
ManuLRK


<mailto:rick-page@shaw. <mailto:rick-page%40shaw.ca>
ca?subject=Re:%20Low%20kV%20Small%20Motors>
Reply to sender | Reply
<mailto:lrk-torquemax@ <mailto:lrk-torquemax%40yahoogroups.com>
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otors> to group
Messages
<http://groups.
<http://groups.yahoo.com/group/lrk-torquemax/message/12484;_ylc=X3oDMTM2
> yahoo.com/group/lrk-torquemax/message/12484;_ylc=X3oDMTM2
YTBpZmI4BF9TAzk3MzU5NzE0BGdycElkAzMyMDUzNDcEZ3Jwc3BJZAMxNzA1MzcwODA4BG1z
Z0lkAzEyNDg2BHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTI1OTYwMjQ4NQR0cGNJZAMxMjQ4
NA--> in this topic (3)


[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]

>>Why are there so few small outrunners (30 to 100watts)
>>that have low kVs (700 to 900)?
>Most really small motors only use 1-3 cells to save weight so the kV
has to be higher to get useful rpm's. Currents are low at these sizes
but as motors get larger it is better to increase voltage and decrease
kV.
>Rick.
Single cell Lipo battery capacities are available from a few 100th  mAh
to 1000th (10.000 ?) mAh ., weight should not be a reason why small
motors can't be run on higher voltages!?
So "higher voltage" should always be chosen if possible? (Power lost =
I^2 * R)
ManuLRK


  <mailto:rick-page@...?subject=Re:%20Low%20kV%20Small%20Motors>
Reply to sender | Reply
<mailto:lrk-torquemax@yahoogroups.com?subject=Re:%20Low%20kV%20Small%20M
otors>  to group
Messages
<http://groups.yahoo.com/group/lrk-torquemax/message/12484;_ylc=X3oDMTM2
YTBpZmI4BF9TAzk3MzU5NzE0BGdycElkAzMyMDUzNDcEZ3Jwc3BJZAMxNzA1MzcwODA4BG1z
Z0lkAzEyNDg2BHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTI1OTYwMjQ4NQR0cGNJZAMxMjQ4
NA-->  in this topic (3)



[Non-text portions of this message have been removed]

>Why are there so few small outrunners (30 to 100watts)
>that have low kVs (700 to 900)?
Most really small motors only use 1-3 cells to save weight so the kV has to be
higher to get useful rpm's. Currents are low at these sizes but as motors get
larger it is better to increase voltage and decrease kV.

Rick.

Hi Bob
You are right, there are few outrunners < 50g with low Kv
additionaly to Himax there is his one
** Tahmazo ER1812-660 wght 28.4g announced Kv 660 rpm/V
I have no sample of it, and no test
If you go to 2212-2215 stator size (about 60-65g)  the choice is bigger (Pulso,
Motrolfly, Dualsky ..)

Or you have also some kits to DIY with a lot of turns -Wye
Louis




________________________________
De : Robert (Bob) P. Andris <bob@...>
À : lrk-torquemax@yahoogroups.com
Envoyé le : Sam 28 Novembre 2009, 19 h 51 min 12 s
Objet : [lrk] Low kV Small Motors


Question for Ron and all others.  Why are there so few small outrunners (30 to
100watts) that have low kVs (700 to 900)?  For instance, HiMaxx makes the
HC2212-0840, which is a 50watt motor with a kV of 850.

Thanks,
Bob
............ ......... ......... ......... ......... ......... ...
Robert P. Andris
12155 Terrence Ave.
Saratoga, CA 95070
USA

(408) 252-5469

bob@andrisfamily. net

LSF 004, AMA 5055







[Non-text portions of this message have been removed]

Question for Ron and all others.  Why are there so few small outrunners (30 to
100watts) that have low kVs (700 to 900)?  For instance, HiMaxx makes the
HC2212-0840, which is a 50watt motor with a kV of 850.

Thanks,
       Bob
............................................................
Robert P. Andris
12155 Terrence Ave.
Saratoga, CA 95070
USA

(408) 252-5469

bob@...

LSF 004, AMA 5055

Helmut singer just got in one 75kg lot of enamel wire in possibly
useful diameters:
<http://www.surplusasnew.de/stock/-263350915.html>

No affiliation, just spotted it and thought that may be useful for
someone making motors, lots of motors....

ST

Yes,

I am grateful for the response, helped greatly.Grateful
Paulo

--- Em dom, 22/11/09, Rick Page <rick-page@...> escreveu:

De: Rick Page <rick-page@...>
Assunto: Re: [lrk] Magnet arc ou line?
Para: lrk-torquemax@yahoogroups.com
Data: Domingo, 22 de Novembro de 2009, 16:16
















 









       The list strips attachments so I didn't see your picture.



But the short answer is that arc magnets are better. If you consider a motor
will 2 poles and 2 flat magnets you can clearly see that the magnet is not very
effective. As the number of flat magnet segments goes up, it increasingly
approximates the field of a magnet that is already shaped in an arc.



However, given that, forming a magnet with a radius may not gain any advantages
over many flat segments. Flat magnets are cheaper and don't have to be created
to match each stator diameter.



Rick.




























      
________________________________________________________________________________\
____
Veja quais são os assuntos do momento no Yahoo! +Buscados
http://br.maisbuscados.yahoo.com

[Non-text portions of this message have been removed]

The list strips attachments so I didn't see your picture.

But the short answer is that arc magnets are better. If you consider a motor
will 2 poles and 2 flat magnets you can clearly see that the magnet is not very
effective. As the number of flat magnet segments goes up, it increasingly
approximates the field of a magnet that is already shaped in an arc.

However, given that, forming a magnet with a radius may not gain any advantages
over many flat segments. Flat magnets are cheaper and don't have to be created
to match each stator diameter.

Rick.

The trick is to know  want want and the amount you want to spend.

Is this a battery powered/portable application?
What is your voltage source?
What is your rpm range?
What is your budget for motor, controller, power supply?
Do you need to adjust/control the rpm accurately?
Do you need use/control low end rpm (less than 20% of max) as well as
the high end?
Continuous at 2kw or intermittant?
Do you need to start the motor with a high load already on it?
How many do you need?

Hobbyking or Hobbycity has the

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5142&Product_\
Name=Turnigy_80-100-B_130Kv_Brushless_Outrunner_%28eq:_70-55%29

Which is a 130kv motor capable of 2kw on a continuous basis. Add a
$190 controller

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=10332&Product\
_Name=Turnigy_Monster-2000_200A_4-12S_Brushless_ESC

and a RC servo servo tester and you are in basic business if the rpm
matches and so forth.

The problem with sensorless motors and controllers is that they cannot
start with a high torque load (they just sit there and buzz) and they
do not have good low speed (>20% max) speed control.

Let us know the answer to the above questions and maybe we can help
find a motor/controller that will work.

David Steinke
Tucson, AZ


On Thu, Nov 19, 2009 at 7:41 AM, pbp_et <pbp_et@...> wrote:
> There is or rather ARE: Try hobbyking.com
> regards
> Poul Børge
>
> --- In lrk-torquemax@yahoogroups.com, "mike" <miker_54491@...> wrote:
>>
>> anyone know if there is a commercialy avalible 0utrunner in the 2kw range?
the company i work for uses a lot of off the shelf motots around that size.
usualy servos or steppers. but steppers are not making it because of the power
drop-off as the speed increases. servo prices startout at nuts and go up from
there...
>> Mike
>>
>
>
>
>
> ------------------------------------
>
> =======================================================================
> MOTOR BUILDING FAQs
> Excellent motorbuilding articles by Brian Mulder,they cover the all the
basics, a must read:
> http://www.southernsoaringclub.org.za/
> -> Articles by SouthEasterners.
> -> Electric Motors - part 1-5
>
> Do-it-yourself motor homepages, manuals/tutorials, checks and tests in this
motor builders tips and tricks thread. The checks and tests may save you from
*frying* your controller or motor. Thread is active, bookmark it for future
reference and subscribe to it:
> http://www.rcgroups.com/forums/showthread.php?t=240993 (sticky thread, at top
of subforum)
>
> =======================================================================
> MAIL DELIVERY OPTIONS
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> Help: lrk-torquemax-help@yahoogroups.com (empty message)Yahoo! Groups Links
>
>
>
>

Dear
members,
 
Good day!
 
I have a question, as below:
 
Please, one question:
 
yellow shows loss of flow of the magnet and coil in the stator tooth
red shows continuity of flow of the magnet and coil in the stator tooth
Conclusion: magnet arc has a better answer magnet planar
 (see picture in attack)
 
A magnet that has arc, ie, which has a radius of curvature, it loses some of the
magnetic field, over another magnet that is rectangular planar without radius of
curvature. I, I think so, because the magnetic flux in a magnet with rectangular
planar surfaces, the flow is in the surrounding suburbs since the magnet arc, so
far as the fold closes in, there is proximity of the flow fields in the
extremities, thus an electric motor stator teeth are also borne by facilitating
the magnets pass in front, thus the magnet and the tooth and the two arcs, the
formation of magnetic flux meets tooth formation, as in the case of rectangular
planar magnet passing in front of the tooth of the stator, will present problems
of loss in the extremities, that the ends move away from the center of the tooth
with a greater reluctance among iron, so I ask: which of the magnets is better
in response normal rectangular or arc with radius equal to the radius of the
stator tooth,
  see the drawings to have a good understanding.
 
Best,
 
Paulo
 


      
________________________________________________________________________________\
____
Veja quais são os assuntos do momento no Yahoo! +Buscados
http://br.maisbuscados.yahoo.com

[Non-text portions of this message have been removed]

There is or rather ARE: Try hobbyking.com
regards
Poul Børge

--- In lrk-torquemax@yahoogroups.com, "mike" <miker_54491@...> wrote:
>
> anyone know if there is a commercialy avalible 0utrunner in the 2kw range? the
company i work for uses a lot of off the shelf motots around that size. usualy
servos or steppers. but steppers are not making it because of the power drop-off
as the speed increases. servo prices startout at nuts and go up from there...
> Mike
>

Goedendag Mike and all,

> anyone know if there is a commercialy avalible
> 0utrunner in the 2kw range? ...
A list of outrunner manufacturers:
http://www.rclineforum.de/forum/thread.php?threadid=43664

Vriendelijke groeten ;-) Ron van Sommeren
near Nijmegen, the Netherlands

Check out www.scorpionsystem.com

Lot's of out runner that can run over 2 KW.



From: lrk-torquemax@yahoogroups.com [mailto:lrk-torquemax@yahoogroups.com]
On Behalf Of mike
Sent: Wednesday, November 18, 2009 10:51 PM
To: lrk-torquemax@yahoogroups.com
Subject: [lrk] big one





anyone know if there is a commercialy avalible 0utrunner in the 2kw range?
the company i work for uses a lot of off the shelf motots around that size.
usualy servos or steppers. but steppers are not making it because of the
power drop-off as the speed increases. servo prices startout at nuts and go
up from there...
Mike





[Non-text portions of this message have been removed]

http://www.modelmotors.cz/

Hi Mike
There are a lot of outrunners in the range 2kW
Generally sensorless for RC big planes
If you look about a weight >1kg (<2W per gram) the power could be "continuous"
Typical brands Scorpion, Dualsky, Hacker, Plettenberg, Neu ... cheap Turnigy ...
But you could find different Kv rpm/V
Louis




________________________________
De : mike <miker_54491@...>
À : lrk-torquemax@yahoogroups.com
Envoyé le : Mer 18 Novembre 2009, 15 h 51 min 15 s
Objet : [lrk] big one


anyone know if there is a commercialy avalible 0utrunner in the 2kw range? the
company i work for uses a lot of off the shelf motots around that size. usualy
servos or steppers. but steppers are not making it because of the power drop-off
as the speed increases. servo prices startout at nuts and go up from there...
Mike







[Non-text portions of this message have been removed]

anyone know if there is a commercialy avalible 0utrunner in the 2kw range? the
company i work for uses a lot of off the shelf motots around that size. usualy
servos or steppers. but steppers are not making it because of the power drop-off
as the speed increases. servo prices startout at nuts and go up from there...
Mike

Thanks, Ron.

After a few attempts, I finally got a response from AC world.

Laminations are about 0.33 mm.
They couldn't seem to measure the inner diameter for some reason.

I was really hoping for a better quality stator, so I did not press more for an
inner diameter.

pete b



To: lrk-torquemax@yahoogroups.com
From: ron.van.sommeren@...
Date: Fri, 13 Nov 2009 14:42:05 +0000
Subject: [lrk] Re: Aircraft World 20 mm stator




























       Goedendag Pete,



> Does anybody know what the lamination thickness and inner

> diameter of the Aircraft World 20 mm stators?

See this thread:

<http://www.rcgroups.com/forums/showthread.php?t=294891>



Prettig weekend ;-) Ron van Sommeren

near Nijmegen, Netherlands


















_________________________________________________________________
Windows 7: Unclutter your desktop.
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_WIN_evergreen:112009

[Non-text portions of this message have been removed]