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Old Mar 04, 2003, 07:47 AM
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Tokyo, Japan
Joined Nov 2002
855 Posts
Re: Shimizu-san

I hope you could get it.
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Old Mar 04, 2003, 10:21 AM
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San Diego Lindberg, California, United States
Joined Jan 2002
1,288 Posts
arigatou

takao-san:
Thanks for the end view picture, it was very helpful.
The close up picture is also appreciated. On your motor, what sort of wire size did you use ? 0.7mm phi ? This is just a wild guess but if the motor is spinning at 30k rpm, the field windings are also switching at 30,000/60 x 3 x 2 = 3 kHz. Which seems low enough that skin effect(hifu kouka) might not be significant, but some how I think that due to the sharp edges of the drive waveform, less the inductive effect of the field windings, there might be an advantage to using a smaller gauge wire ? It might be easier to wind with the stranded wire. Have you experimented with the type of wire you used ?

EP
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Old Mar 04, 2003, 03:00 PM
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Germany, BY, Gräfelfing
Joined Jan 2003
425 Posts
Hi EP,
may be i can help you also.
First,to make the wire with lize wire is ok but you get not so much copper inside,the isolation takes some room.Better to take not a single but 4,5-6 strands is ok.Itīs not skin effekt it is edy current wath is better in moore strands.The amps make edy current inside the wire,spezialy in single big copper,at high amps and these is less in smaler strands.
Also the rotating magnet makes edy curent in the wire.

An other method of wireing a air gap coil is to make tree coils with no overlapping each other.
Take the dia X Pi of the magnet to get the outer(do not know the word).Then /3 to get the aera for the every of the tree coils.Glue a wood stick2,5 x 2,5 mm in the middle of each coil aera and wire now the copper around these sticks.The stikes are so long as the magnet is.So you get coils with short overhang at the each end of the magnet.
To get moore magnetic flux i am wireing iron wire around the ready made copper coils.You can use green painted iron wire from floristshop of thinner from hobby shop.take these wire so thinn as you can get.
How much ironwire you make around is to your expirements,much iron lowers the rpm but iron loss get higher,less iron rised the rpmīs but torque is less,so you need a higher gearing.
I hoppe you anderstand my answere.
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Old Mar 05, 2003, 06:57 AM
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Tokyo, Japan
Joined Nov 2002
855 Posts
Re: Skin effect

epkoncept,

>0.7mm phi ?

I have bulk 0.7mm phi copper wire. This is the only reason to make this motor with 0.7mm phi wire.

>there might be an advantage to using a smaller gauge wire?

No, I don't think so. My ESC has resisters on each gate of driver FET to reduce the RF noise and inductive kick. This is quite important for high power drive to get safety margin of device operation. This is more important of switching power dissipation loss of FET.

Have you experimented with the type of wire you used ?

No, I have not. I have no experience of skin effect problem on my designed motors as explained above with my driver design. I would like to test the feeding maximum current of this motor(before burn out?). My motor may eats over 50A, I feel. You can feel cool at the coil after fly with 8.4V 2.4Ah Ni-Cd battery.
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Last edited by Takao Shimizu; Mar 05, 2003 at 07:07 AM.
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Old Mar 29, 2003, 02:19 PM
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San Diego Lindberg, California, United States
Joined Jan 2002
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takao-san ? What about iron ?

takao-san:
Now I understand how you have the field windings located via the plastic end plates. However, I can not tell whether or not you have any iron ? Does your brushless motor havee any iron in the field windings or between the rotor and field windings ? Do you know if other brushless two pole motors like Hacker or Lehner use iron to increase the flux of the field windings ? If you are using some iron in the field windings, can you show a picture of what you used for the iron stators ?
EP
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Old Mar 30, 2003, 06:25 PM
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Tokyo, Japan
Joined Nov 2002
855 Posts
Re: takao-san ? What about iron ?

epkoncept,

>how you have the field windings located via the plastic end plates.

I could say that the end plate is not useful.

>I can not tell whether or not you have any iron ?

There is no iron magnetic shield. The leackge magnet fileds kiss screws, bolts like any irons near the motor. This is problem.

>Does your brushless motor havee any iron in the field windings or between the rotor and field windings ?

No, there is no iron plate.

>Do you know if other brushless two pole motors like Hacker or Lehner use iron to increase the flux of the field windings ?

The small space gap between coils and magnet is important. Most of anothers are for magnetic shield effect, I think.

>f you are using some iron in the field windings, can you show a picture of what you used for the iron stators ?

There is no difference of magnet and slot-less coils between others and mine, except magnetic shield ring with the expensive machine made outer case.

http://www.rcgroups.com/forums/showt...5&pagenumber=3
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Old Jun 08, 2003, 06:46 PM
Impossible? Hah!
KreAture's Avatar
Oslo Fornebu, Norway
Joined Jun 2003
3,074 Posts
Could you try and run a rewound CD-rom motor with your controller? I'd be very interested in the results
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Old Sep 01, 2003, 10:26 AM
homo ludens modellisticus
Ron van Sommeren's Avatar
near Nijmegen, Netherlands
Joined Feb 2001
10,509 Posts
A slightly different approach, no need for a lathe at all:
http://www.rclineforum.de/forum/thre...did=36382&sid=

http://www.ppi.se/cjo/Slotless1.htm

http://www.rc-network.de/cgi-bin/ubb...2;t=000455;p=2
http://www.rc-network.de/cgi-bin/ubb...2;t=000455;p=3

Met vriendelijke groet Ron van Sommeren
• diy outrunner brushless e-motor discussion.
• Electric fly-in & lrk meet, June 27th, 2004, Nijmegen, the Netherlands.
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Last edited by Ron van Sommeren; Sep 01, 2003 at 10:28 AM.
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Old Nov 25, 2003, 05:33 AM
Registered User
Tokyo, Japan
Joined Nov 2002
855 Posts
Better source program

My home page is closed.
I hope this program works better.
(I am making all new software)
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Old Nov 25, 2003, 01:59 PM
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Baltimore Bwi Rr Stn, Maryland, United States
Joined Oct 2003
520 Posts
Takao,

Just wanted to jump in with comments on PICs versus Atmel. You can get an in circuit debugger for their flash parts for $150 US. This has proven to me to be more effective than an ICE. Also CCS has a PIC C compliler for $100. I have tried the Atmel parts and keep going back to PICs.
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Old Nov 27, 2003, 08:24 AM
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Tokyo, Japan
Joined Nov 2002
855 Posts
I edit the post to change the schematic.
Sorry, the old one was the BL servo schematic, not BL ESC.
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Old Nov 30, 2003, 07:28 AM
alx
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Russia
Joined Nov 2003
2 Posts
brushless controller

Dear Takao,

Thank you for the brushless controller schematic and for the program source!

And I have some questions:

I want to repeat your controller without making any changes. Will it work with a brushless cd-rom motor? Or I need to adjust the program according to the motor I'm going to use? Or may be your controller is universal for all 3 phase brushless motors?

Thank you.
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Old Nov 30, 2003, 08:12 AM
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Tokyo, Japan
Joined Nov 2002
855 Posts
Re: brushless controller

alx,

>Will it work with a brushless cd-rom motor?

This ESC is too big for CD-ROM plane.
I have never tested this for CD-ROM drive.

I am making all new simple BL ESC circuit and drive software.
It is under construction as the photo shows.

I use a comparator on the ATMEL chip in stead of OP amps.
You may find the detail explanation on TB6537P/F Toshiba brushless driver chip data sheet.
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Last edited by Takao Shimizu; Nov 30, 2003 at 08:47 AM.
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Old Nov 30, 2003, 12:11 PM
alx
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Russia
Joined Nov 2003
2 Posts
Dear Takao,

Thank you for the fast reply.
Now everything is clear. As I understand your new simple BL ESC will be suitable for light plane based on cd-rom motor, right? If yes, I'll be waiting for that! By the way, are you going to share your new BL ESC schematic/program with anybody?
I'm doing my first steps in electro planes modelling, and your ideas will be really very helpful for me. One more thing, sorry, if it's offtopic: could you, please, help me to get some information (links, plans...) about cd-rom motor based rc planes? I know, you can build such planes very well (I've seen some photos)!

Best wishes,
alx.
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Old Dec 01, 2003, 08:24 PM
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zagisrule!'s Avatar
Edgewood, NM
Joined Jan 2002
1,038 Posts
I have tried Takao's design, but I had trouble arming the last controller with my Airtronics and JR radios. Hopefully this version will do better

Thanks alot Takao!
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