RC India

I recently acquired this 2212. It had jumped off its mount. I opened it i.e seperated the bell and armature to find the wires badly damaged. Can it be dismantled further to attach new wires? 

Sundaramvelar is one person who can help you on this. Shoot him a PM and request him for his help. All the best!

i also have the same problem on one of my 2212/13 motor

sure you can

Well, I couldn't open it any further.  :banghead:
Even if I had, I might not have been able to fix those (shattered) insulated wires. :(
Gonna have to buy a new one...

Don't loose heart and loose the fight so soon Swapnil my friend, Many in the forum like me, to name some like Ashta sir, Roopesh, Kalyan (maybe), rotorzone are happily rewinding and using old burnt out brushless motors. will be glad to of help.  I have not thrown out a single Brushless or Brushed motor I have bought till date. I have rewinded and revived all of them and using happily till date.

to begin with let me give you copy of powerpoint presentation which I got hold of some time back on the net, on basics of Brushless Motor and their rewinding technique. PM me your email ID.

Note for Admin : I am not sure of the copyright status on posting slide photo shots of the presentation for benefit of all. Please clarify

Egerly waiting for the PPT. Also would like to know the tools required

regards
Pankaj

@sundaramvelar: Sir, the motor isn't burnt. The wires got twisted and broken (at the point shown by the ellipse in the attached pic). How to seperate the winding frame and the bronze coloured base (marked 'A' and 'B' in the pic) ? If I could seperate 'A' and 'B', soldering fresh wires would be easy! 

About rewinding, well, I'm a newbie, so trying to rewind the motor might make everything worse and consume time as well!

Aluminium frame (Bronze Coloured) and the soft iron 12 pole winding core is factory press fitted using heavy machinery, attempting to separate them at scratch build level will lead to ir-repairable damage to both. without separating them if you can manage to extend the wire by soldering and insulating with shrink wrap you can still manage to revive without having to rewind.

I would buy a new 2212 if I were you.
Because, even if you repaired it, I am pretty sure it wont run as good as it ran when you bought it.
A new one is about $11 i guess.

 .
sir you are right but there , by looking at picture it seems that the winding is ok , only the ends are diamaged, but if the winding are burnt then it will aslo burn esc , i thing after insulating the end by extending each end and unwind it only for one time,  he should check the resistance of it.

i think its a part of hobby and  it depends on individual .

Yeah, exactly what I was thinking. :)
I'm gonna get a new one and let this one rest.

Looks toasted to me :headscratch:

So,if you're getting a new one,you can try repairing this right? ;D Eitherway,you're not gonna lose anything.

No sir, it's not toasted. It just flew off the mount and got twisted.

Repairing? Well, as the pics show, the wires are damaged beyond repair. And as sundaramvelar sir says it can't be dismantled any further for repair, all that can be done is let the good thing rest in peace!
And I'm not gonna lose anything anyways, it's not mine ;D.

I said only the iron core cannot be dismantled from the aluminium body, but it can sure be repaired by rewinding.

@samanth I do not agree on that a re-winded motor is not as good as the new. All Brushless motors are hand winded in all cases. The care with which it can be hand re-winded cannot be matched by any machine.

Hand re-winded motors are as good as the new. What more you have the flexibility to play around a bit with KV ratings and wattages of the motor.

Only with practice and persistence we have perfected for ourself. What is the worse it can happen is you might have to redo it all over again.

Winding of a motor take just 30 Min max if you have all the required material ready at hand.

@sunlikestar by the colour of the winding on the photographs it sure looks toasted, I wonder why the dark black colour.

Sandy, do you REALLY think it is toasted?

On second thought it appears as if it has been given a second coat of different dark coloured enamel after winding of the poles.

I think the motor is toasted... If you see the first picture, you can see both the colours of the wire, copper colour and black colour, through the aluminium body. What is the condition of the ESC? Please check the ESC by connecting it to another motor.

Yes sir, that's what I think too. Because it certainly doesn't smell like it's toasted.

Anam bhaiyya, it was sent to me by a friend and he said "...it came off the mount and got twisted a little , you need to put a sleeve and solder it a bit". I don't know about the ESC. But I'm sure he wouldn't send me a toasted motor. :)

Sandy sir, I'm gonna keep it in a box till I get a bit experienced with all these things and then try rewinding it. ;D

Swapnil can you tell me how many magnets are there in all inside the Motor can?

14.

Please refer to the KH-257-2.pdf file I have sent you. You can try with lesser wattage by using a thinner wire with equal number of winding for all the 12 poles in the manner as shown in this attached sketch.

Hey swapnil You were the latest sweepstakes winner!!!!!!. I missed that.

Please send the Motor to me I will rewind and send it back to you. I have sent you my mailing address as PM.  :)

Thanks sir!   ;D
PM'ed you my address.

The BLDC Motor arrived three days back.  I was busy with my aquarium (5’ x 2’ x 1 ¼ ‘) build so could not work on it. The Aquarium is over and beautifully done, Thanks to encouragements, Motivations and ideas from our very helpful VC  :hatsoff:.

The Cir-Clip was removed with a 1mm screw driver tip and the Magnet Cans and the mounting base was separated by pulling out.
First of all, as we all had doubted the winding was not fried but it was actually given a coat of darker coloured enamel/ Varnish after having wound. (It is going to make my day of removing them easily that much more difficult  :banghead:)

Some Preliminary Check before you wind any Brushless more applicable to a BLDC motor from a crashed model or a really over heated and fried Motor.

(a)   Magnetic debris inside motor: There was only a small magnetic Spec inside, which was easily removed and the core and magnets were clean.

(b)   Check Magnets:  All fourteen Magnets were intact and were not loose. However if incase if any magnets are loose you would have to push them tight inside their aluminum slot on the Iron Can and fixed permanent with a very small dab of CA each, Keeping in mind the correct Magnetic polarity this case NSNSNSNSNSNSNS (making sure none of this CA come in contact with the Motor Shaft or flows into the bearings.  I this case since all magnets were fixed tight inside the can, However to make sure it was all given a very small amount of CA. In case there is no slot then fixing them at the correct point at the section is even more difficult and needs to be done with care and proper measurement and setting out.

(c)   Check Motor Shaft:  Check that the Motor Shaft is absolutely straight and easily goes in and comes out of both the bearing. The Shaft was absolutely straight.

(d)   Check bearings:  Check both the Bearings of the motor, that it is freely rotating the can and the shaft, without any rumbling or grumbling. Here in an attempt to remove the cir-clip I think Swapnil had dented one of the outer protective sleeve. However the bearings are running smooth so no worries on that aspect. However this is something to be kept note of while removing the Cir-Clip that right tool is used and the bearing are not damaged.

(e)   Tight fitting of Iron Motor Can on the aluminum body:  In one of my earlier case of rewinding the Iron Can which is press fitted on the aluminum mounting base, it had come loose from the aluminum Mounting base along with magnets  which was required to be again tapped back in with my Goldsmith Hammer and fixed secure with a dab of CA but not a case here.

In spite of all the checks and removing the magnetic debris when the motor was assembled back and especially when the cir-clip was put back it was giving out a minute scratching sound. I had to open the can again.

On closer Inspection I found that,  Swapnil in an attempt the separate the Iron poles and the mounting base with a metallic object had dented the poles corners and the corners of the Poles had deformed and a small projection had come up at four places which was rubbing against the magnets.
However no issues I think I can put it back to shape with my Goldsmith Hammer with light gentle taps or file it back to shape as the kinks are less than half an mm.  :thumbsup:

Photographs of tools used and process follows.

Oh, I'm so crappy with tools :banghead: . Good thing it didn't cause much damage.

Thanks so much for the info+tutorial sir!
Waiting for the pics...

PS: Would love to see pics of your new aquarium too.  ;D 

Nice post sundaramvelar, this will be useful for every one {:)}
subscribed & rep++

Hi,
I Think this page might be relevent for rewinding.
For rewinding the only thing is to keep in mind that count the turn of each phase in each slot.
Another thing I recomend to use good quality of vernish in coils for good heat dissipation.

http://www.flyelectric.ukgateway.net/motors.htm
http://homepages.enterprise.net/jayjay/cdrom_motors.htm

Thanks.

Picture of the Aquarium first for Swapnil.

Some more Photos

Wow! That is a lovely tank!

Just a few suggestions (if I may) : That tank needs more plants and you know where to get them!  ;D Goldfish and live plants don't go well together. Undergravel filters are not usually used when live plants are thriving in an aquarium.

Btw, in the first and second pics, is it a Moonlight Gourami? They are bloody aggressive creatures and will harass the peaceful Goldfish a lot.

All the best Sandy!

Thanks VC. I agree with you these guys have been plucking out the plants from where it has been tied to stone with thread. they have been planted again. Here in shillong nothing is available, so put together with whatever was available. Thanks for the offer.

I should be able to send you some soon. Couldn't trace out the shop in Shillong that i had mentioned earlier. I've planted some Sword Amazons for you and I'm waiting for the cuttings to root. Matter of time now.

Oohhhh....beautiful sir, so beautiful!  (:|~  {:)}  :thumbsup:

I really liked the third one of the ship with a fish (having so many fins) floating just above it. And the stones have been laid out really aesthetically too!

Cool work by Sundaram sir and VC sir.  :hatsoff:

Wonder if one could try putting a gold-fish sized RC submarine in there?  :P ;D ;)
....to play with the fishies!  ;D ;D ;D


.

Thanks VC. Thanks Swapnil.

@ Swapnil thats one serious suggestion worth a try. I have to take help of VC for that.

Swapnil, what are you complimenting me for? I haven't done a thing! It is all Sandy's hard work. As far as the sub is concerned :

http://www.dealextreme.com/p/r-c-submarine-2ch-4658

A word of caution : The rotating props can hurt the fish.

VC sir, the compliment was for all the 'help' mentioned by Sandy sir above. I've come to realize that sometimes this sort of help is as much responsible for the final product as the hard work put in.

How about a DIY sub with water-pump propulsion instead of propellers?
I made a small 6 cm water-pump (for a boat) using 3v toy motor some 6-7 years ago. It used to work really well. With a little water-proofing we could use it in a mini-sub!

VC sir, have you tried your hands at underwater crafts? After your scratchbuilt hovercrafts ( :bow: ), we would certainly like to learn about DIY subs from you!  :)   

Swapnil, this is exactly what i am looking for! Please share the plans for this water pump. Are you using an impeller mechanism or are you powering a syringe to draw water?

I have been designing a submarine for quite some time now and plan to start work on it soon. Your water pump will prove to be invaluable. Thanks!

It was a centrifugal pump (with impeller mechanism). It was built in 2004, I don't have it anymore to post any pics.
But it's really easy to build and can be completed in less than 20 mins!
The motor I used was a 3V toy-motor (around 1000 RPM without gearbox). We could use a 600 RPM geared motor for greater torque.
I'm currently working on my first scratch-built plane and drawing the plan for the pump would require some time. Is it O.K if I post the plans in evening?

Take your time Buddy. There is no hurry at all. First get on with your plane.

Now for the actual rewinding part of the Motor.

First is removing of the existing broken or burnt winding:-

Use a 1mm x 0.25 mm tip to lever out the Circlip holding the Can and the mounting base at the Shaft. Do not use any other screw driver, Knife, nose plier, nails, scissor etc.

Pull out the CAN with the magnets away from the Mounting base with winding Coils.

Clip out the Bullet connectors if it is present. Remove the heat shrink wrap from the Three wires carefully without damaging the strands of the wires.

During the entire process of winding keep the Magnet Can in a separate plastic seal packet safely away from magnetic debries and dust. Further protect the bearings of the Motor also from Dust by not dropping it in one.

Some of the Photographs pertaining the the Reply #28 on: June 13, 2011, 03:14:38 PM

is attached please they are

The Aluminium Slot on the mounting base where the Magnets are tightly fitted.

The press fitting of Iron CAN and the AL mounting base.

The Kinks at three places due to attempts by Swapnil to remove the iron core with a metallic object.

Removing the winding has to be done exactly in the reverse order of the winding process. Therefore after having removed the Shrink Wraps carefully separate the SIX bunches of Strands of enamel insulated wires i.e. the start and finish ends of the three Phases of the Brushless.

Separate them as shown in photographs carefully, taking care that the strands are not mixed up between different ends. Splice them together as six separate bunches.

Unwinding has to be done exactly in the reverse order. So trace the finish ends of the last Phase which was wounded. which will come off the poles without much effort.

Unwinding has to be done using hand only since winding has also been done with hand which has to be done with repeated soft tugs at the wire bunches around each pole. Do not use Nose pliers unless if it is a totally jammed wires stuck together with Epoxy or enamel. In any case if Pliers are used the enamel wire will break and you will loose the ends for unwinding and then you will have to get into the difficult process of cutting the wires and removing the coils and again trace back the ends.

Unwinding the first Phase ( Last wound ) is going to be little difficult as it will be very tight fit. Once the first phase is unwound then it will be relatively easy to unwound the motor.

Here in this case as suspected earlier, due to the coat of Enamel/ Varnish to the complete winding, right at the first Pole shoe the strands of the Bunch started breaking being stuck in enamel/ Varnish  :banghead:  :banghead:  :banghead:. Half way on the first pole I lost the end completely due to breakage. I in fact doubted whether I will be able to unwind the motor at all. All logic went for a six.  ???

But patience and persistence and delicate handling with Pen knife and 1 mm Sharp tip shaped out of a high tensile metal pin, in this case a metal push rod, played the trick. Strand by strand wire by wire was removed from the four pole of the first phase.

There after it was much easier to tug out inspite of the enamel/ Varnish.

All the phase were removed completely without any damage to the motor, but wire in many pieces.

Ideally it should be removed in three equal lengths of bunches of the strands or a single strand.

The motor was wound in the exact same manner as the recomended winding posted earlier in the thread. It had 10 Turns per pole. the winding was comprising of five strands of the enamel insulated wire for each of the three bunches of the phase.

Wow, that's one handy tutorial. Thanks Sandy sir!  :hatsoff:

VC sir, I'm sure you know the insides of a centrifugal pump very well. The one I made was similar to the water-pumps used in coolers. I made the impeller by sticking rectangular plates on a gel-refill. The plastic cylinder was a 'lime bottle' used in 'paan-shops' (small green coloured one). It's approximately the size of the small motor.
I didn't experiment much with it then, so can't tell the RPM required to generate the required pressure. I used the motor without a gearbox and it worked well. I'm sure you'll make a better, more efficient and powerful design.
Attached pic...

Sandy sir, have you finished rewinding the motor? I'm really eager to see it work! :)

Thanks for reminding me buddy  :) .

I was caught up with business at work. Then had a great time with VC yesterday.

Though from here after the application of epoxy and curing for smoothness of the corners, it is just 1/2 to 1 hours effort but it is still eluding me.

will complete and update.

Great! I had a question bothering me. Will the rewinded motor have the same kv as before? Also, will the stall current rating change?

KV Though is mainly dictated by the number of poles and number of Magnets for optimum wattage. However it varies based on the number of turns and the wattage by both number of turns and gauge of the winding.

Sir, what I intended to ask was, have you made any changes to the no. of turns and guage (as compared to the original)?

I have not yet started winding the motor. But yes there is going to be marginal changes. because the winding  though will be same turns but will slightly vary in gauge and number of strands.

And that won't drastically affect the kv, will it?

it was a 1400 KV it will be plus minus 100.

O.K. so I guess it will still have the same prop range (approximately)...

I have a similar issue now with a 2826 motor, i couldnt reach to rewind as the bottom aluminum frame cannot be removed.
Bell motors are kind of different it was very easy to remove and rewind a towerpro motor.

Send it to Sandy sir!  ;) :P ;D

Bearing are now removed and was sucessfull loosing the stator from the alluminium plate.
It took 2hrs of heating with soldering iron for the glue to release the stator. Now its freely rotating but still is not coming out.
Followed  the last few posts in http://www.rcgroups.com/forums/showthread.php?t=1079423

finally was able to seperate stator and alluminium base!! A drop of oil did the trick.

Well all that effort is surely worth it if you are able to get the pole shoes core out without damaging it and the bearings without  damage. Though all that heating did not damage the varnish and insulation of core?.

If you are able to remove core shoes out then it surely makes your life easy while rewinding.

Now back to Swapnil's motor, in preperation for its winding it has been given a thin coat of eppoxy on the core to smooth the edges to prevent damage to enamel wire while rewinding. It will set over night then it will be ready for rewinding.

wow, very good going sunder sir .

{:)} {:)} {:)}

Sandy sir, when you rewind the motor, is it possible to increase the kv to 1700-1800? I was hoping to use it with 5-6 inch props as they do non break easily.

For Increasing KV I have to reduce No of turns per pole and increase the Gauge of the winding which will also increase the wattage.
let me see how much I can do it without over loading it.

Oh yes, I forgot about the increase in wattage with kv! I only have a 30 Amp ESC. :(
How much will the wattage increase with turns and guage? Is there any mathematical relation for that?

KV has no relation to the wattage. All KV Range is available for all wattage.

Wattage is purely = Volts x Amps. and Amps is dictated by the Resistance of the coil of the Phase And Impedance for the coil in rotation. Impedance is also dependent on Resistance in addition to various other factors like flux, load (resistance to motion in the field), number of turns of the coil, core properties, air gap, frequency, and may be I am missing out some.

However When you increase the thickness of the gauge of enamel wire and reduce the number of turn. Surely you are reducing the length and increasing thickness and the resistance is bound to fall drastically. Which will increase Amps and hence the wattage increase.

Some of the relations I am posting just for Knowledge sake

Watts per pound of airplane weight.
100w/lbs = trainer/sport
150w/lbs = 3D aerobatics
200w/lbs = extreme

And wattage is calculated as
Watts = volts * current
7.4v * 10amps = 74watts
11.1v * 25amps = 277watts
22v * 50amps = 1110watts

Motor Kv: Kv = RPM / (Vin - Vloss), Vloss = Iin * Rm

Torque constant: Torque constant: Kt=Kb x 1.345, Kb = Voltage constant (Volt/1000 RPM)

Doubling the number of winds halves Kv (rpm/volt) and doubles Kt (torque/Ampere),
Doubling stator height halves Kv, doubles Kt and (roughly) doubles maximum power.

Higher the dia of the Motor Lower is the KV Higher is the Torque.

6 cycle step sequences needed to complete 1 revolution of the magnetic field.
A to B / C to B / C to A / B to A / B to C / A to C

Examples of gearing of the Motor because of No of Stator and No of Magnet:
10 magnet
   360deg / 10 mag = 36deg || 36deg / 3 phase = 12deg
   (12deg / step) x 6 steps = 72deg. Sequence
   360deg / 72deg = 5  or 5:1 gearing

14magnet
    360deg / 14 mag = 25.71deg || 25.71deg / 3 phase = 8.57deg
   (8.57deg / step) x 6 steps = 51.42deg. Sequence
   360deg / 51.42deg = 7  or 7:1 gearing

Higher the Gearing ratio Higher is the Torque and lower is the KV and Vice verse. In other words higher the number of Magnets lesser is the Number of KV - higher is the torque due to Gear Ratio.

A, B, C are the Three Phases. When it is in Capital it is Clockwise winding and When in Small it is anticlockwise winding.

9-pole stator can only be wound using ABC wind
ABC - ABCABCABC

12-pole stator can be wound either ABC, LRK or DLRK.
ABC – ABCABCABCABC (easy, need more magnets)
LRK – A-b-C-a-B-c (high wrap count per tooth, less to wind)
DLRK – AabBCcaABbcC (low wrap count per tooth, more to wind

In Delta system of connection it gives 1.73 times more KV than the Star system of connection whereas gives 1.73 time less KT (Torque).

Since it was 12 Pole and 14 magnet Motor applicable winding was DLRK The picture posted earlier. Posting in-spite of repetition for closer reference.

The photographs of the three phases wound.

Since Swapnil wanted a little Higher KV it is now 8 Turns per pole in place of 10 Turns but Gauge is I think almost same.

I could not get the correct thinner strand for multi strand winding which would have given a smoother winding, less noisy motor and some say cooler winding.

I have used a single strand of thicker winding which was comfortably filling up the pole shoe without crowding and enough space for cooling air too.

Leading end the the trailing end are protected from nic at the corners with heat shrink wrap.

If it was 16 magnet Motor the recommended ABC as the picture posted below.

And a 9 Pole Shoe is always ABC Winding as below Which is also an example of Delta for of connection.

Example of star connection is the second picture.

The Delta Connection for the Swapnil's Motor is as shown in the picture.

Here you have to be very carefull for DLRK and LRK with the sequence unlike an ABC winding.

In ABC winding the Start end  and finish End of two different phases have to be connected and the six ends have to be paired to three sets by connecting the starting end and finishing end two diff phases in any sequence (Just don't connect ends of same phase  :giggle:). Since all winding is Clockwise it can be done in any sequence without any effect on the motor only the direction of the rotation will change.

However since in DLRK and LRK the winding are alternating Clockwise and anti clockwise the sequence have to be strictly maintained as per the sketch for Delta.

For star just connect and solder all the ends and give three phase supply to the three start ends.

Swapnil,

Till now I thought the bearings were OK since when rotated with Hand it is not giving any noise. But when powered up it has a small rumbling at low RPM i think one of the bearing towards the Clip side is dented and is slightly damaged.

You can still use the motor without any worry only it is more noisy. earlier I thought because of thicker strand but it is distinctly rumbling at low RPM like play in the bearing. Otherwise it is spinning at good RPM.

Earlier I did not doubt it now I can feel it when in free rotation with hand also. Now only since I know it I can make out it is that light.

I will load test it and post photos and video with wattage and temp results.

Wow, thanks sir! This thread is turning out to be a really informative tutorial.
We'll be eagerly waiting for the test photos and vids.

waiting for testing ...

sundaramvelar sir,
thanks a lot for the information on rewinding...
i too winded my motor with the help of this post...
and special thanks to ANGAD who guided me ....
(http://i706.photobucket.com/albums/ww69/TEJASCOOL007/2011-07-16142600.jpg)
(http://i706.photobucket.com/albums/ww69/TEJASCOOL007/2011-07-16142549.jpg)
(http://i706.photobucket.com/albums/ww69/TEJASCOOL007/2011-07-16142002.jpg)
(http://i706.photobucket.com/albums/ww69/TEJASCOOL007/2011-07-16133153.jpg)
:salute: :salute: :salute:

You could have reduced the number of turns per pole by two or three for more even fill. However since you have been able to wind all poles no worries.

no sir i have kept turns tthe same ie.15 turns
instead i changed the wire used
previously 3 wires bunch was used now a single thick wire as seen in pics
will that do....????

That what I was implying since you have used a thicker wire you could have reduced the number of turns per pole by two. It would have reduced the crowding and would have a more even winding. Now that you have been able to complete all pole without wire spilling outside the pole shoes no issues.

I had tested and recorded video long time back but could not convert it and load it because of some my Codec problems in my laptop. downloaded the latest codec K Lite full version and now I could convert and load it.

For testing the Motor I used a 7 x4 Pusher Prop since I wanted to measure the the thrust also.

I have mounted the Prop pushing the air away and with a digital scale which is tared to be zero with the complete set up, placed on top of it. I am measuring the Thrust approximately by the weight of thrust.

Watch the video please

http://www.vimeo.com/26728397

It gave a thrust of around 500 gms on full throttle with a 7 x 4 Pusher Prop consuming less than 15 Amps and less than 150 Watts. Should be able to try with 8x4 on a model for short burst of full throttle runs and bigger props with 2S Lipos

Now for an example of ABC winding. I have chosen a really micro 9 pole motor with 12 Magnet.

This was a motor which I bought from ebay, this is a three grams micro brushless. It came damaged in transit with supply wire entwined with shaft and was not freely rotating.

Now I plan to revive it. It had 16 turns per pole. It was 7000 KV 1S motor.

Some photo graphs of dissembled motor. Lucky that my Dell streak is able to take really!! closeup photographs. When rewinding I need to work under magnifying glass for this motor.

I'm thinking about rewind my 3536 motor. I've never done anything like this before and looking forward to some DIY fun :) So what kind of wire should i get, what is it called? Any chance of finding it around the block (eg: in repair shops) or will i have to hit the electronics market ???

Electronics Bazaar is the right to place ask for enamel insulated Copper Wire. Avoid Enamel insulated Alluminium wires. Any Transformer/ motor rewinding chaps will be having it. What is used for transformer low voltage side windings and for field coil of motors is the right bet. They are available in varying gauges. It would be best to take the sample of wire already wound in your BLDC for obtaining the enamel insulated wire.
 

ok. thanks for the tips :thumbsup:

this is a easy task, if you have the interest, take sample wires to your local electronic shop and tell him to give you the winding roll for that wire diameter. Before you unwind the motor, carefully keep a count of your turns.
It will work!

Regards,

CF.

Hi , Sundram sir thanks for sharing wonderful knowledge with us all. :salute:  Your knowledge encouraged me to again try rewinding my brushless. I trieda 3 times before, following you-tube videos, but no success. I tried your ABC system this time and guess what it worked..   ;D
my brushless is with 6 magnets and 9 poles. RPM was 3100 with factory settings . 
I didnt remember how was the factory winding. But now its rpm has incresed as seen pratically ( no instrument with me to know RPM )
 Now it is not moving 8'' prop, making sound, but moves 7''DD prop well. Why so ??? :headscratch:
I wind it with 7 turns with 26 gauge (approx), as beyond 7 were not possible, overcrowded. What i can do to increase torque.
 Prior i used 9'' prop before it damaged.   Attaching my brushless pics after winding.

You'll have to increase number of turns to increase torque, how many turns did the motor had before?

Your is a 6 Magnet, 9 Pole Motor which is basically designed for High KV more than 2500, unlike a 12 magnet 9 Pole Motor which is designed for KV less than 2500.

It is better you use the same 7 turns per pole configuration for full efficiency, with smaller props for a high speed plane.

It is not advisable to use a Larger prop for a high KV motor. I wonder How you were able to use a 9 inch prop earlier for a 3100 KV motor.  :headscratch:

Like what sunlikestar has said if you use more number of turns per pole with thinner gauge wire then your KV will reduce and Torque will increase, but your being a 6 Magnet Motor it is not desirable to reduce KV very much since it is basically designed for High KV.

Sundaram sir, but can u give me a idea, how much amp it is drawing from my lipo. And which Amp ESC will be suitable for it, lipo capacity ? What could be the thrust approx

Watt meter is a best choice for it, since Amp drawn and thrust are all dependent on various factors. prop size, pitch of prop, static and dynamic, voltage applied, motor size, length of winding, no of turns per pole, thickness of wire, capacity of ESC used and many more.

I've finished winding using this image (http://www.rcindia.org/electric-power/can-this-bldc-motor-be-repaired/?action=dlattach;attach=639388;image) posted earlier in the thread, now i'm totally confused which ends to join  :banghead: i forgot which end is the starting point :help:  

Just finished my motor and its alive now :) Have not measure amp draw and kv yet but its looking good.
I just twisted adjacent wires where you started is not important; got this tip from here a 5:30
http://vimeo.com/18554942

 :salute:

Can anyone tell me how to download the above video from vimeo.

I use downloadhelper plugin in firefox with FDM.
While playing any movie, downloadhelper gives me the option for download.
And if different varient available, I get options which one to download too.
Just try, it's easy.

And if you want to edit or convert, just use K-Lite mega codec pack and TMPGExp Portable.

Thanks

Try this http://keepvid.com/ fast and simple :thumbsup:

Thanks Friends..... {:)}

Sundaram Sir..it was a great sharing of knowledge, and actually, by mind i was sitting in front of you, on a bench, with desk, as in my academic years..as you mentioned, from my modeling life i never thrown out any motors as lost, and even now working on new 3, as brushed, and two as ECMs..as i am more intertested in ship and boat modeling, i usually rewinds all motors with more windings with thin guage wires..and yes, was inspiring and immensly valuable..a million thanks for the effort to teach us the step by step procedures..a million salute.. :salute: :salute: :salute: :hatsoff:

Hey plz can you send me the information to how to rewind bldc motor ........thanks.....

Rahul plz read this entire post from the first page, every thing about rewinding is explained here within.  :)

its too easy to rework on any motors..may be a brushed or brush less..i got lots of motors from various sources, and now rewinding all for my needs..you can see here is a heavy motor rated at 12 Volts and 15 Amps..but later i reworked 3 of them to 12 volts 1.5 Amps..and about 4000 RPM..cool..

we can buy, or collect needed SWG wires from any electronic spare dealers..make sure it is all good HD copper..

this motor was in 1000 RPM/Volt, and rated at 9 Amps, at 11.1 Volts. i lost it's three poles, in a crash..and rewinded it for my specs for ship modeling. so, my need is less RPM, with comparatively great torque. you can see here how easy to rewind a motor, to our needs..

you can see the rewindings..here as all according to my needs..i took about 20 minutes to wind it all tightly..

after insulating installed the rotor..

you can see, previously, this motor no load current was 1.8 Amps..but after reworks, it takes only a mere 520 mAmps..at 12 volts..

and even at stall load with fingers it is only about 800 to 900 mAmps..so,? hours of running time for boats and ships..but with all needed power ratios..ample os woooms...so, please do not throw away your burned motors..may be MCM or ECMs..if you are going to discare..please give it to me.. :giggle:

i once again saying a million thanks to sundaram sir, for the greatly detailed drwings of various configurations, of ECMs..even a child can follow..Sir..a million salute for your encouragements.. :salute:

have you all some nice reworked motors..try it..all easy..

i got this micro motor from one of the respected Member of RCI, as damaged.. the winding was damaged and was far beyond recovery.. and at beginning i was not much interested because of its size..  but after rework, it showed its mettle.. and so happy that to make a simply fly with a span of 24 inch..
cleaning the web was some hard work as the company was using a tight insulation coating on it.. but with some patience cleanned well.. and ready for rework..

after full cleaning started winding.. used 26 SWG instead of 24 original.. more RPM..and yes in to STAR.. more torque..

you can see how simple is to rework.. its now ready for the test..

once completed.. oh my GOD.. i amazed with its immense power.. at 7.4 volts she hauled a 5X4 prop with ease for long time test without any fail or over heating.. !!  so time to make a good plane of its class..  here once again.. reworking a BLDC motor is quite easy.. try it.. rework it.. and RCyit..  :thumbsup:

Interesting video on how to mechanically control speed of brushless without the use of ESC

www.facebook.com/EngenhariaEletricaEletronica/videos/1031341783576854