I have just finished my first scratch build plane. But there has been a prob. When i connected a fully charged lipo battery to esc, everything at first worked fine. The motor worked fine for the first time, then i reduced the throttle to zero and the motor stopped, but when i again moved the throttle forward, the motor behaved abnormally, like it made fraction of revolutions clockwise, then anticlockwise and so on, it did not make full turns . Then i disconnected the battery and i reconnected it, the same problem appeared. Again i disconnected and reconnected and the problem disappeared, everything worked fine. So, the situation seems very abnormal, sometimes the problem appears sometimes everything works fine. Dnt know whats going on?
My motor: A2212-10, esc- dys 20amp purchased from sai sir.
The servos work fine.

The motor also suddenly stops after running and starts to make slight clockwise or anticlockwise movements haphazardly. The esc is suppose to make a series of tones(noise) as soon as i plug in the battery, sometimes it does, sometimes doesnt and it also gets hot very fast.

which prop are u using and check whether motor heats abnormally!

No the motor doesnt heat. I am using an 8*6 prop(GWS). I know there is nothing wrong with the compatibility of all electronics with each other because they were all suggested by Sai uncle.

Please make sure to keep your throttle at zero before connecting to battery. Then wait for few seconds until the beeping is over. Then move the throttle or you will go to program mode. Please check and make sure all you soldering points are correct without any loose contact. Switch on the TX first.

ESC getting hot and cutting off (or struggling) can be an indication of too much amps draw.  Now amps draw can be unusually high if the wrong prop is used or if if the motor is bad. You need to double check any soldering you did also.

The simplest is to see if a higher amps ESC solves this issue, if you have one handy (or if you can borrow one from someone just for testing)

May be the weight of the model also to be checked Anwar Gi ??

Of course ! That is the first thing to check in such cases. But I thought the testing was being done on the ground and not by flying the model in this case.

You are spot on It looks like test done on the ground only as you suggested, so weight factor is not in picture 

esc problem for sure

There are 3 wires connecting the ESC to the motor. If one of the wires is not connected Properly then For sure this problem happens. There can be 2 faulty items.

1)The electronics of One of the wires of the ESC that is generating the pulses is gone bad. Usually this is not the problem.

2)One of the wires that are connected to the motor is not connected properly. This is usually the problem! Make sure all are connected properly. First time your motor ran and next time due to vibrations one of the wires may have got disconnected. The wire may also be cut somewhere near or inside the motor so take your call and examine this properly. Try soldering the wire directly to the ESC and try.

Note that when the motor is doing this kind of to and fro motion, increasing the throttle will definitely fry the motor in seconds. So dont throttle up more than required till the problem is fixed.  

Also sometime changing the ESC timings also have solved problems for many.   But don't play with timings unless its a big motor. Small motor and high timings some times dont match and burn up.

same happens with me!
but as told by vinay the solution is clear

Here is a video of the behavior. I have personally experienced this at home on the same turnigy motor. But after connecting the leads properly, it worked SIMPLY FINE!

WOW I have never seen a smoking Motor

Whoa, thanks so much everybody especially vinay bhaiya. The problem is fixed, actually the soldering of one of the wires which connects the esc to the motor came loose and hence resulted in the problem. As instructed, i directly soldered the esc and motor wires and now everything just works perfect. . And i was lucky enough not to fry the motor.

Good news. 

Vinay - Did you mean to say that your smoked motor still worked fine leaving no permanent damage to it ?  So what generated the smoke ? Only insulating wax etc inside ?

No Anwar Bhai, I did not smoke my motor, I was already aware of such problems before it even occurred . Thanks for the Forums, Youtube and moderators and all the helping people around

I believe the smoking happens as the energy provided by the ESC does not get dissipated as the motor does not turn and this undissipated energy turns to heat. Imagine all that energy in terms of 200 to 300 watts thats provided to the motor thats twice the size of our thumbs(its almost equvalent to 5 times of what our ceiling fans consume at full speed )

your  plane fly

Quote from: vineet on July 11, 2010, 11:22:01 AM
your  plane fly

I need to do minor adjustments with the CG. Hope to get the maiden flight tommorow if it doesn't rain here in Kolkata.

Quote from: vinay on July 10, 2010, 06:58:44 AM
Also sometime changing the ESC timings also have solved problems for many.

Hi Vinay,
Please explain how we can change the ESC timings?

How to choose best ESC + motor combination ? for ex. Model: TR35-30-B having Max. efficiency current : 10~15A. So, ESC with just above 23A (15A * 1.5 = 22.5 ) could be a best choice?

Pls add your valuable suggestions?

Regards
Dileep

Do not mess with timing unless you are forced.  Since your problem is solved, it is better to leave the timing alone

It is done the same way most ESCs are programmed... you can find related discussion here :

http://www.rcindia.org/electric-power/esc-programming/msg8000/#msg8000

A commonly used rule of thumb for ESC selection is to add 20% to the peak amps drawn by the motor... so look at the motor/prop combo and lookup the motors datasheet, that should tell you the amps draw.  But if the AUW of your plane is not within the power/wattage range of the motor, all of this is irrelevant, and something would end up getting damaged.

Yup you are right, 1.35 to 1.5X seems to be good. BTW You can use any ESC that has Max amps less than the Burst amps of the motor (to be on the safer side). YOu can change the timings using a programming card or do a stick programming using the ESC manual. Though you dont need to change the timing if your setup is already good.

Also remember that some times some ESCs dont match up with some motors at all and give a lot of trouble. Though this is rare, this knowledge of mismatch comes only with experience / reading on the net before buying.