RC India

Today while flying my bird , i connected the motor to a 3s 1600mAh Li-Po . The moment my throttle stick crossed 50% the power got cut . Upto 50% throttle its working pretty fine. Checked the ESC by plugging in an another motor , ESC working fine. Checked for any wire cuts on the motor , found nothing . Can anyone please help ? :-\

which motor and prop are u using ...basically looks like a motor overloading problem.....

I am using http://www.hobbyking.com/hobbyking/store/__2046__TowerPro_Brushless_Outrunner_2409_12T.html this motor with a 30 amps ESC . I already had around 10 flights with this motor. Today after 2 flights this problem occurred.

Due to loading at higher speed the voltage drooped below the cutoff voltage.
Check batt , they should be fully charged.
Check cut off voltage setting of ESC.

bhavesh
similar problem occurred with me too..the issue is with your motor..as rc vish suggested there is a problem of motor overloading. the motor you using requires 25amps esc.so esc problem is outrooted.
what i did is,i rewinded my motor and the problem solved...there is a thread on motor rewinding on rcindia.org.

thanks.
hitesh

Mr. Hitesh
Is this motor rewinding thing complicated i mean can i get it done in any ordinary electric shop?

see its not that much complicated if you are into electronics and stuff.c there are two ways of winding a motor -star or delta connection.as i told you there is a thread on motor rewinding issue which a person had.search it,go through it and if you feel its complicated then find a person near you who could assist you..clear pictures have been posted which will definitely help you..

thanks..
hitesh..

here's the link-----
http://www.rcindia.org/electric-power/can-this-bldc-motor-be-repaired/msg65222/#msg65222

bhavesh..check the winding of your motor, for any burns and short circuit..rewinding a ECM is easy.. :thumbsup:

Bhavesh..this happens because of these things..if the motor is designed for 7 or 9 volts..as the coil resistance decreases, the pulse from the ESC will be partially blocked..at high voltages..so, a over load protection circuit instantly trips the supply to motor..for saving itself..so, at first stay calm..at first program your ESC, as "Factory Default"..this can be done by programing it, by switching on the TX and Rx, while obeying the instructions from manufacturer..after resetting the ESC, try once again, but listen, before that, you must configure the maximum throttle range, of the Tx, RX with ESC, while obeying the throttle range set up instructions of ESC..after setting you will hear a beep, ( may vary in various ESCs..) as conformation..still you face the same prob, connect the ESC to a 7.2 volt battery..if clear, connect a good motor to same ESC, and feed it with 12 volts again..if it works fine, it is sure, your motor is in problem..you may cooked it once..reworking on a ECM is far easy, and finding its guage, turns all are nothing..you can go for even good wires, last for a life time..(HD Copper)..you can remove the motor outrunner cup, by removing the E clip, at shaft, and can examine the windings..in some cases, the whole winding must not be coocked, but only a few, may be inside, hard to find with bare eyes..you can determine this by checking the resistance of each coil, means branch, of each, by digital multi meter, or can find with storage osciloscope, by taking feed back loops..if still persists, please do not throw your motor..it is far easy to rewind.. :thumbsup:

Hitesh, R/C Vish, Roopesh,

Here's what I am thinking aloud.

The motor's just a piece of wire inside a magnetic chamber. When current flows it rotates the bell. If current exceeds wire's capacity the wire will melt, requiring a motor re-wiring. So a motor should be a on/off switch to the current applied.

In this particular case, the motor ran for 10 successful flights before giving this problem. The motor is working fine till half throttle, and after 50% throttle it stops rotating. Motor exhibits this problem consistently. So for a on/off switch behavior it's a ON switch. ESC issue is eliminated out by checking on a different setup. I am doubting the battery. Is it possible that the battery has gone weak after 10 or so flights and not able to supply sufficient current when stick is > 50% and drops in voltage. Due to drop in voltage the ESC is cutting supply to the motor.

I am just theorizing. I may be wrong. But if I am wrong even after testing the motor with a different battery, then I would request you knowledgeable folks to shed some light on the motor's winding and the abrupt stopping of the motor.

Ashu..thats why i told him, to check the ESC, with an other motor, on a 12 volt source..

Please do check the setup with a different 3S Lipo fully charged This happens even if one cell of a 3S lipo going bad. Or after prolonged usages of  B grade or C grade lipo whose C rating of discharge deteriorates.

Many ESCs need the throttle end point calibrated.  You do this by putting the throttle stick at max, connecting the lipo to the ESC, and after the first couple of beeps quickly reduce throttle to zero. 

Same thing happend to me couple of days before, i did programing to ESC, Like anwar said.
This may be helpfull: http://www.rcindia.org/electric-power/plz-help-soon-motor-beeping-and-did-not-start/
 

Hi,

two thing is missed hare, that what ESC you are using, And what Prop with this mtor.
This is due to the reason of overloading. You might use an over-pitched prop or larger dia prop so that before rated speed, it takes full load current and so ESC goes to safety shut down.

So, what prop you are using ? Look, the prop you should replace should satisfy the criteria that new one should move same volume of air  with one turn rotation of prop like recommended. You may under-load the motor but should not overload it with prop.

I think the thing changes with replacing the PROP.

Thanks

Well i tried everything , changing the ESC, LiPo , plugging the ESC and LiPo to another motor all is well .
Tested the motor without the load and its working perfectly fine but with propeller the same problem is their.
Probably ill go for a winding change at some local shop. Thank You people for your valuable inputs.

This problem has been faced by a lot of beginners (including me). The motor runs fine without prop for the whole throttle range but stops abruptly at about 50% throttle with prop attached.

Have you tried re-calibrating the throttle end points? Which radio do you have?

Hey people i have found out that the motor winding has burnt so need to get it rewinded.

Bhavesh..from your given link related to your motor, i came to know that its a motor with 3 mm self shaft..if it was a normal one, means, with a 4 mm shaft, i will take it as now, and give you a brand new motor from DYS..actually, i am waiting to alter the winding of the motor, to reduce it's RPM, but to increases the torque..as i have to use on a boat..sadly, shaft of your motor is 3 mm, cant use on my boat model..dont worry..winding your motor is far easy, take about 20 minutes, and leave two or more windings, each pole, so can avoid some over heating..and in to delta..slowly, remove the main present winding and take a good piece to electronic shop, so can identify the SWG of the used wire..so can buy some wire, take about 50 Rs..and can go for next flight..within hours.. :thumbsup:

Bhavesh, You may also use this video for your reference http://vimeo.com/18554942 along with the rcindia post http://www.rcindia.org/electric-power/can-this-bldc-motor-be-repaired/msg65222/#msg65222.

But I still don't understand, if the motor's windings were screwed up why did it work even till 50%.  :headscratch:

Good point! When it happened with me, resetting the throttle end-points worked.
Get the rewinding done from an expert or just buy a new one. Doing it yourself is not a good idea if you haven't done it before.

Yes Mr. Swapnil i am looking for someone who can rewind the motor for me. I dont wanna take a risk doing it all by myself

I do not think your motor needs rewinding.  It will work fine with the recommended prop and battery.

Jitender

O.K. I googled this problem, went through 7-8 results and found this on 'wattflyer':

"If one or more of the strands gets broken, or burned, the motor will still run at low throttle settings but have difficulty running at higher levels, especially under load. Especially if the motor is connected delta, then it will be seriously unbalanced electrically and the problem becomes much worse at higher power levels."

Mr. Swapnil the current condition of the motor is that the wire is completely turned dark in colour and the armature was hot and i could smell the wire burn.

Mr. Jitendra i have been using this motor for almost 3 months never had a problem before and i still used it with the same ESC and the LiPo.

Probably i am going to rewind it myself. Seems easy as seen in the video.
But need some help getting the right gauge of wire

Swapnil has settled the point whether burnt or not.
But even if you rewind it, it will burn again if you do not find the answer to why it happened in the first place.One thing is sure ,it was over heated , because it takes a lot of temperature to turn enameled copper wire black.

jitender

may be due to wrong prop size and pitch..or by wrong timing value of ESC..by adding a simple aluminum circle, just bigger than the motor base with fins helps cool motor even better in high rated conditions.. :thumbsup: