I have a broken down seagate barracuda 80GB hard disk. I am planning to build a brushless motor from it . I was able to take away the rotor, but the stator with coil is stuck to the hardisk casing. Cant remove it.......

Anybody got a nice way to take it away without any damage ?

Well, take it to nearest Engg Workshop, say them to cut in the outer lining of the motor in a circle!! I hope they will do it as in my town I personally assisted them to do that!!

Thanks I just got that my self. I did it in the hard way. Just hammered it and cut it with an axe saw blade.  

Now i am going to rewind it.

What is the right gauge of copper wire for my job. 

Use the search box on the top-right and search for motor winding.

choosing the winding wire is all up to you, as according to your needs.. you can rewind the motor with thick single wire, or can use thin multiple wires.. the result will be almost same, but multiple wire winding will be better in some cases.. and you can choose the configuration as STAR, or DELTA, is also falls according to your needs.. if you post a picture of the motor stator along with the out runner, can guide you easily.. but usually the SWG stands from 26 to 35 can be used all according to the final need.. if you need more RPM than torque, can choose the DELTA config.. and if you need more torque than speed.. choose the STAR.. this rewinding will take about 20 minutes aprox.. so, at first determine your need.. and go for rework.. will be a nice motor.. 

 

Thanks........... for all that

I Just wound the motor with 26 gauge wire, 17 turns at a pole with star configuration.  

Now looking forward to test  

yes..nice.. and one more tip.. most of these motors are appropriate for up 7 to 9 volts maximum.. because of the nature of construction.. and try to test it with a 6 volt supply at starting.. try different ESC timings for a good results.. will power your crafts nicely.. 

i,m Just 16 and my parents wont let me buy online

I am looking forward to make a fully home made rc plane....

I gona make a stepper motor controler and test the motor.........

later....

nice.. it is easy to make a ECM control by simple electronic components..have  nice flights..

My pics

 

Cant find any good esc circuits... all of them to be programmed.

tested with dc gets small movements .....

do BL motors work fine in AC.

Else i should find a good esc.

Are there any good rc outlets in trivandrum

i already told you that, if you are a beginner in electronics it will be a little hard to make an ESC for ECM.. ECMs will work in AC currents.. but you have to increase the cycle/second.. and in DC ECM will be a good brake, and when voltage and current exceeds a little it will start to heat up.. you can find many Local Hobby Sellers in our forum.. you must find some time to read some articles carefully and patiently.. must go to the RC Gems, at welcome screen, and must take a good readings.. and you cant achieve a good thing without some perseverence.. work hard.. will gain.. 

Copy that   

all we are happy to help all.. so dont worry.. try to understand the working principles of motors once.. from basic.. so you will find that the principle behind all motors are same.. the electromegnetic induction..!!  may be Mechanically brushed, or by Electronically Commutated.. have a nice sucsess..

There are some masters here in Electronics than me. You have to think it own.
Who says ESC without uC cannot be made ? It can be made, some options will not be available and weight will not even be near convensional SMD uC based ESC.

So, I am giving the simple design IDEA for them.

This is for Electronics Designers only.

Just think of brushed ESC speed sensing LPF and make pulse generator (Astable multivibrator) through that voltage.
Trigger 4017 (6 state counter,i.e. 7 goes to reset.) for state diversion. Use Diode array and buffers for 3 phase switchs (3 NMOS and 3 PMOS).

But the serious drawback is you have to adjust POT manually for different KV motors as it is without feedback and cannot be made feedback with load angle but can be made with load current for fail-safe operation.

Receiver signal  ==> Astable Multivibrator ==> 4017 state divider ==> Diode array ==> 2x3 matrix CMOS Switches.

Thanks

Floppy drive also have brushless in them.
Here are some re winded brushless .
Hdd, floppy drive, Cd drive.
Amazing thing is that. Inspite the smallest of three, Cd drive brushless motor is most powerfull and can be winded easily. All Crdit to
Mr. Roopeshji For his brilliant tutorials.

Respected members , i have  found a low cost brushless motor controller circuit.

Kalyan, great idea.. but with ny expiriments, saw the speed is some limited..
Mubarak, is that circuit is capable to drive a heavy one like a 1000 RPM/Volt motor..?

Sir in this video it is saying about 9100 rpms and the max amp rating is about 1.

video link :




Forums :

http://www.radiokot.ru/forum/viewtopic.php?f=17&t=11976&start=180

http://vrtp.ru/index.php?s=94f8550da7f7a979a2574f0ee6744775&showtopic=16590&st=0


All in Russian, please use google translate

Another perfect circuit with NE555, CD4017 and some transistors

video:




This circuit resembles KALYANPRODHAN sir's idea.

 

Much more simple circuit using 6 mosfet and hdd motor with hall sensors.

video :

All the problem is neighter with RPM, nor the size, but the POWER for us using in Plane.
High power demands high current and low loss transistor hence MOS is the ideal.
Moreover, different Motor loading pattern (Different KV and current to) sensing gives error as feed back and adjusting frequency of ESC Oscilator is problematic. Only thing that is perfect measurement for any motor and any current, any KV is the torque angle which perfectly feeds back the motor loading and adjust with throttle set point (Throttle stick position.)


And this can only be achieved easily with uC, otherwise, the discrete driving circuit may weight 4 times than Motor.
------------- All this if you want same ESC to be used with different motor. But if you use same motor with single ESC, you can use this and be benificial. And hope everything will be under 300 .

Except otherwise, the magnets replaced with NEO magnets, Max. flux dencity (Φ) will not be grate and power = I x Φ x Cosα , And Back EMF will be corresponding to Φ, so, Same speed with more loading will resulting less α and hence, at α _max it can take much more load if Mech. load demanded .

And all you know, DC motors are cheapest and DC ESCs(DIY) too. Only problem is the GearBox. Laserjet Cartridges are with gears and if similar gears manufactured, Indigenous power system will be achieved for foamy.

Mubrak, what translator program you use, google or bablefish , while accessing .ru domain ?

i used google.....

Bldc tester

video:

good.. nice efforts..

More videos:

 

direct testing of cd rom motor - no esc - no digital circuits......

Mubarak.. how much load it can carry.. and whats about the RPM..? please..

translating the above youtube video description :

" Incredible speed, some 12000 RPM or more!, All with only 12 volts direct without ESC, or digital circuits. "

Sorry roopesh ji, i am not an expert in this area......

nice..

I am motivated to go deeper into its working after watching this video...

Alok.. its too happy to see many creative ideas here..

brushless to brushed....
innovative....

Respected members, i am very great full to your valuable help.   I modified my circuit as shown in the  above video. I also reworked my motor with some very thin copper wire from a transformer. this should provide me with very lesser kv rating. I replaced the 3 - tip31c transistors with one tip3055 and two 2n3055 which was lying around. This time i got lucky and the motor produces some sort of a sound(No movement at all). As i turned my variable resistor the frequency of the sound reduced and each step is heard clearly.
This is evident in the below video :

http://www.youtube.com/watch?v=zLErTg6KIjY&feature=youtu.be

nice..

 Good evening, distinguished members of the forum.

I have been carrying on with this experiment. The results was same with a reworked motor(50 turns of 30swg copper wire). I suppose the problem lies with the transistors. I could not find tip31c. Please suggest me with ideal combination of  transistors for max power.        

Reduce the turn with thick wire.

More turn = less current and more back emf while starts rotating so low torque.
Try 8-10 turn of 22-26 SWG wire per pole / phase.

Waiting for your test result.

Same result with 9 turns of 24 swg copper wire.

Kalyan

He says the motor does not turn at all. So less turns/more torque are really academic, don't you think?

Flyback diodes are missing in the schematic in first post. With a inductive load like a motor, that means instant death of the transistor. Do check if your transistors are still in working condition and add the diodes.

It should move like a stepper motor at low frequencies. However there is no back emf at low speeds so, the current is only limited by the power supply and resistance of the motor winding. Add a resistor between motor and Vm to limit the current to what your power supply can supply. Also watch out for transistors overheating since you don't have any heatsink.