Hello Roopesh Sir,
i am building a Cessna 182 and want to use one of these motors, but i don't know what guage wire should i use and how many turns...
Following are the specs-
1. Plane AUW- ~500 gm
2. Battery -2s (7.4V) lipo
3. Bell Dia. -2.5 cm
4. No of poles in stator- 9
5. And i want to use a slow fly prop, something like a 9050...
So, can you tell which wire should i use?

And one thing more, mine has a grey coloured magnetic ring inside the bell, so do i need to replace it? If yes, then where would i get the neodiyim magnets from?

Thanx in advance

Bilal..its a nice thing to hear..please try with 35 SWG in three strands, and in to 15 turns, and try two more if, and in to DELTA.and you can replace its magnets, with high power ones, can attain from many hobby material sellers. but till now, i was using it with original magnets..and found a little weakness when heated up..but still it is capable..and in boats it is not an issue as i always incorporates water cooling..and a 8 inch prop will be more apropriate..weight is the key enemy of light aircraft, so please try to make your aircraft light as possible..

Thank you Roopesh Sir for your quick responce, but i am unable to understand what you ment by '35 SWG in three strands'.....is this a referrence to the type of connection (delta or star) which you are suggesting or something else?
Sorry, but i am new to the hobby and still unaware of the jargons..
And Sir, the plan am using suggests a 41'' wingspan, will this model be suitable to fly as a parkflyer in a ground as large as two football fields?...if no then what size should i prefer
regards
Bilal

Bilal, a 41" foamie or even slightly bigger ones should do fine with that big a field IMHO.

Bilal..three strands means, and 35 SWG are, yes, instead of using a thick wire, you can use two or three thin wires to the size of a thick wire..the basics and advanced science behind a motor is far complicated..but, we do not need to go to any extreme sides of the motor..because this effort never gives us any benefit, except, knowledge..so, you can wind your motor, with a thick wire, or with three thin wires that the three thin wires must be within the size of a thick wire that we intended to use.. this gives us more tollerance all around.. and it is not a must, that you use multi strand..  can simply go with a thick wire..

the term SWG, is stands for Standard Wire Guage, is a basic measurement, to determine the thickness of a wire..nowadays, this unit is not much in use,but still we can go for it because of the popularity in our country..theres a gauge, as a circle, like a CD, with ample of perforations in it's periphery..holes with various sizes..so, we can insert the wire in to a slot, that fixes nicely, then can read the number from it..26, 35 are denotes the thickness of the wire..and as Sam pointed it will works fine..

you can increase the size of the control surfaces to a slow flyer or park flyer, this enhances control to a great extent at low speeds..

Roopesh Sir,
now i get it,
since B is directly proportional to N, [due to the formula, B=(mu)NI/H], so using multiple wires of less thickness meance increasing the no of turns N, which inreturn inbreases the magnetic field B:)

thank you very much sir, for your help.........its a previlage having you around

-regards
Bilal

Yes..Bilal..and was delibrately avoiding the formulas and technical complications, because, if i post an article with lots of formula here, most of us never look in to it..because, only a few can follow such complications in electronics..and once again, that we do not need to enter in to deep complications of electronics..many of modellers among us keeps distance from electronics, because , we all think about electronics as complicated..but, once we explores through, in simple way, we will amazed, that how easy and exciting is..for an example, we can wire a simple transistor as an electronic switch..its very easy..but, if we looks in to charechteristics and euqtions of a given circuit, we will be in trouble, as it elaborates a lots..here, our motto is learning electronics through in a simplest way..briefly, you are true, and multiple wire strands increases the surface area, among all, it also helps to cool motor a lots..and, yes with a trial and error method we can get very maximum performance from a given motor.. interest, self research, patience are essentials in model making..and now working on a slowest flyer, for my students, and will share once i completed it..so, don't be back..carry on..sucsess guaranteed..have some nice motors , flights, ships, and cars..

Roopesh ji , i Have winded the brushless, from cd rom in star winding and it is working fine , but the issue is it is getting very hot within a minute. can this be rectified. I am powering it with 2s only.

Swiz..coming to your answers..

Usually, motor heats up.. its a must, that, it is carrying out, the task of taking load.. a great load than it's physical size.. and here, it become more, thats because, these motors are not designed for any hard works, but most of the time these tiny motors are designed to work with 4 to 7 volts, controlled by an MCP, and most of the time will be within a few RPM.. even if it goes over 48X.. but here we are pushing these motor up to it's maximum limits, delibrately.. but at any instances it will not goes wrong, if you are prepared..!! so, we can go for a checkout and some simple remedy..

once again.. the motor we use, whatever may be it is, brushed or brushless, cored or coreless must heat to a certain degree.. but if it is going extreme, we must notice some aspects..

most of these tiny motors are apropriate to feed with a 7 to 9 volts maximum, because of its low numbers of pole and magnets.. and the size also.. the selected voltage and feeded load plays an important role in motor handling.. if you rewind this one with a 22 guage wire with 5 turns, you can run it on 4 volts, with a home made ESC.. and will be twice the powerful than a EP 400 motor.. i use this config for smaller boats with tiny battery packs.. but must need a water cooling system, as the motor heats up.. so, this one is not feasible to connect with a 7 volts.. what happens here..?
its all simple..no more equations, formulas, and calculations..only common sense.. that we are rewinding these motors witha 12 to 15 turns.. so, because of the small area of stator, this winding simply acts as a short circuit most.. so, an easy remedy i found is, rewind this with multiple strand, more clearly, 24 SWG in three, and nine volts.. best config..

so, to avoid over heating check these criterias.. before that some own experiences.. these motors are far capable than we think.. i was making lots of models with these tiny marvels.. all working well than imagined.. will share all one by one.. so, if your set up is true, it plyas a nice role in our models.. at present i am working on a little plane that capable of 3D, is intended for oncoming competition, named as Sunflower Bug.. is intented to fly around a big sunflower placed on a flower pot, and must piloted by a little girl Cadet.. in works.. so its so versatile..

now make sure your windings are maching for the voltage of battery packs.. make sure the internal resistance at least as 1.2 Ohms for 7.2 volts.. this can achieved by incresing some turns on stator.. make tight turns.. as possible.. you can use a ball point pen body, with its nozzle, to wind a motor as shown..

to get a tighter winding we can use anything like this one apropriate.. ball point pen bodies, plastic tubes, this carbon fibres..but make sure therent any sharp edges.. to remove insulations..
here showing the simple idea.. by a little practise you can wind tight turns with this.. here it is only a key as i have to photograph it all by one hand.. still you can see how nice and simple it is..

now.. make tight windings with more turns.. or with mutiple strands..
another factor to these motors is the outrunner cups are not ventilated, because these motors are designed to operate in low voltage and currents and it is designed to accomodate a base for the Copmpact Discs.. so, it must be flat and clean.. but here we are pusing it to limits.. so we must need some ventilations around outrunner.. so, it is time to think about making some holes on outrunners..
making holes, more clearly, drilling holes on to a out runner cup of these motor need a deep care as the drilling proses can damage the magnetic rings.. if you are going to add the extra magnets on the cup this is not a problem.. if not care must be taken in to an extra level.. so timne to make holes on outrunner to cool it..
take a good Compass and add a sketch pen on it.. make sure the depth is ok.. and can add a simple gear or anything to hold the compass needle..
draw a circle on out runner cup as it placed on a apropriate surface..

fix the cup firmly.. and start to drill with a metal grade twist drill.. make sure it is running in while clearing the magnet rings.. make sure it as 4 holes.. and need not big holes, but a 4 to 6 mm is enough.. TAKE EXTRA CARE..
after drilling clean all flashes with a smooth hand file..

now turn the cup upside down.. can see fissures and flares.. now must clean inside.. attach a bigger dia twist drill bit to driller.. and make a swash to each holees from inside out..take care..only a little to remove any protutions..not drill out..

now make sure, there is no any protuding metals inside.. and clean it all with an old tooth brush, and make sure no metal particle inside.. left..  MAKE SURE ONCE AGAIN..
can also wash it just with cotton cloth.. and pluck off any particle that still holds by magnets..

fixing a motor directly to a non metallic base reduces heat dissipation.. so, time to add a heat sink on the base of the motor.. we can purchase the heat sinks for GP transistors, from any electronic shops at the rate of Rs 5/- each.. and can add any type of heat sink, as apropriate.. but try like this one..is compact weightless and works fine.. this one is for SL 100 series transistors, and can also purchase from hobby shops, but i found that cost of this heat sink was quoted as 120 Rs /- instead of RS 5 /- here.. !!! 

heat sink installations will gives us 60% heat dissipation on an aero model.. but make sure the motor is not concealed..
here you can see the close up of a heat sink.. its all simple..to attach on a motor base.. apply little threadlock, or 72, 76 Cyano glue to the heat sink inside, not on the base of the motor as the glue can run in to the motor .. press firmly and hold it for some seconds.. before that you can rough inside with a sand paper..so it grabs each other firmly..

now back with out runner cup.. make sure the locking mechanism is perfectly fit on shaft.. you can replace the simple plastic stopper clip with new metallic E clips that can purchased from any Electronics shops..

now add the propeller.. make sure it is firmly tight..
you can check out, that the configuration of the motor as DELTA or Y.. by leaving the wires a little long, as about 3 inches, you can solder the tips of each wire, far from motor, so, can go for a checkout, with each connection as DELTA or STAR.. one apropriate for you.. but make sure motor is fixed firmly on a base..wear an HELMET, and BODY COVERS, while testing.. and cover the gap between neck with thick cloth..make sure no other prople are not standing nearby.. be responsible, not recless because these motors are FAR POWERFUL THAN WE THINK..!!  

if you are intended to run your motor in to one direction, means without reversing it, you can make a bumping on each drilled holes with a smooth round tipped nose plier, as a scoop, to rotating direction, so these bumps acts as scoops that scoops more air in.. cools even better..
make sure the TIMING OF ESC is programmed for your motor.. because most of the ESC are defaulted at factory, for 12 poled motors.. you can program the ESC while looking in to the data sheet of ESC from maker..its fun to realize that 99.9 % of ESC s are made with similar components, with various brand names.. so, you can follow any data sheets to programme it.. make sure the timing is correct, if not, the ESC will pumps in more voltage and current in to motor ..and the back sensing also affected..this affects the performance of ESC and motor..and loses most of the battery power as heat.. so, make sure the ESC timing.. it varies to a high RPM and low RPM motors.. then only can swith it nicely..once mastered these motors gives us a unimaginable RCying pleassre for years..
for water cooling we can go for some easiest options..follows..

one more point..after drilling the outrunner cup, we must balance the cup to avoid any vibrations.. this can be done easily, by placing the motor shaft on two parallel beams like bench vise or on two metal scales placed on a table..if found heavy any side, we can sinply grind off a little from heavy side with a hand file.. try again..untill balance it.. its all easy.. please avoid adding weights to balance motor.. 

Thank You very much roopeshji for that detailed Description. 

its all easy Swiz..the sequential winding and some more tips are follows..

some easy tips for boat modellers..
one of the easiest way to cool a motor on a boat or ship model is placing the motor under water..i tested it nicely and working on most of my boats.. its very easy, and the magnetic flux passes through water, nothing will happen..but it is nessesary to add a simple aluminum net shroud around motor, to avoid spinning water motor itself, and to avoid any weeds and twigs..
after running we can blow up a little air, on to the motor, after pulling out the outrunner cup.. so, here we have to leave the drive shaft without an E clip.. as prop pushes prop in, the shaft will not loose from motor..