lancer123

so i have a brushless motor and it just stopped working today. have no idea why .

its not dirty. not abused. worked last night. and kind of today. and now it wont work

its not the esc, my sidewinder worked fine in his car which is the same BL motor.

not the radio. my radio works fine with his ESC/BL motor

my servo is glich free



also when i give it throttle it wont spin . it just pulses forward then spins backwards every time i give it throttle . it like vibrates , it wont spin constantly in one direction but forward then back really quick (like it spins one way then back every .01second . probably not even 1 RPM yet ..the more throttle i give it it pulses harder and faster.

its never been abused . and sand never got into it .

the motor beep sounds sound diffent now, and the motor and ESC gets warm in like 30 second.



is my motor shorting its self out ? esc gets like 90 degrees warm after like 10 sec same with motor and the wires are warm too .
and in my lil bros car after like 10 sec of actually spinning at high rpms its still is pretty cold same with ESC

the BL motor is no brand off ebay. this is the 3rd one and the 1st 2motors worked fine, so did this one until today.

http://www.youtube.com/watch?v=NuBdi...e=channel_page
http://www.youtube.com/watch?v=ihZ13...eature=channel

http://www.youtube.com/watch?v=JWFta...eature=channel

midntpumkin

if its getting warm within a few seconds then i would think you over heated the motor. if you have an ohm meter check the ohm of his motor compared to yours, that should tell you if you fryed it

Druss

If it's a cheap off brand from ebay then I'd just replace it. I guess you just got a bad one.

How many runs did you give it before it started doing this? Have you oiled the bearing lately?

lancer123

its never been over heated i guarantee

i check my motor temps very often and i run fans on then my mamba 8000kv was way over heated ,

bearings are super smooth . probably had like 5 runs only the motor is the newest one too out of the 3 . motor spins freely


my dad says its has internal shorting. but the wires arent cut. or anything .

Druss

All I'm saying is that when you buy from a no name brand made in china then the QA/QC is not up to most manufacturers standards. The thing to keep in mind is that even when NA or European manufacturers have their products made in China they design the QA/QC and will reject anything not meeting those standards. If it's a chinese company making a copy then those QA/QC standards go out the window as they just add cost and lower profit. It's not like they are going to warranty their product or anything....

Just as a note, my company both has items manufactured in china to our standards, and also buys chinese manufacturers products. We also buy from India, Taiwan... etc. A lot of what we resell are commodities (tarps and textiles) and price is the only consideration. Other items are part of engineered systems and MUST be built to certain tolerances, those are the ones we have made to our standards. Believe me, we went through something like 20-30 trials before we were satisfied and we're only talking about extrusion molded plastics.

nukervilletrolle

Vibrating means most likely one of the three motor legs is bad. If that is the case, you cannot really repair it.

lancer123

rly ?


well here is the motor OHM reading

lil bros motor :

black,red - 0.3
red, white -0.3
black ,white -0.3



BROKEN MOTOR
black-red 0.7
red, white - jumps alot, but when i push the wire down i got it to read between 1.9-3.4 smallest reading
black, white jumps alot, but when i push the wire down i got it to read between .7-3.4 smallest reading



so i guess a wire is broken inside it .

midntpumkin

yea, i think it may have over reved and blew itself up , if this is the motor they dont take much to blow and over power . http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=4213&Product_Name=KB20-30-15S_6200kv_Brushless_Motor_(FIN)
or this one
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=3849&Product_Name=KB20-40-17L_3400kv_Brushless_Motor_(FIN)_

lancer123

but there isnt any smoke or anything

unlike my lil bros old motor its smoked .


i'll try to see if i can fix it tomorrow

hse32

Could it mean your battery are died

traxxas4ever

teh same thing happeed to my mamba 5700kv motor. one day it just died and pulsed pack and forth building up a ton of heat. however it got majorly overheated the day before. it got up to 280 degrees. so that was understandable. those motors cant take that heat. however my theory is that the ebay motor was cheapy and the motor melted something inside it at the higher end of the normal tempeture scale like 160 or 170 degrees. this is the only thing i can think of if he says he never overheated it.

Access

Here is the thing to do.

Can you turn the shaft in a complete rotation or two when the motor is unpowered?

If so, the coil is damaged. Fixing this isn't worth the cost, just get a new motor.

If the shaft cannot be forced into making a full rotation, your rotor is damaged. You can likely open the motor up, remove the rotor and any debris, get a new rotor, and you should be good to go. Unless the rotor breaking caused some additional internal damage. If you do have an ohm-meter, check each coil like the guy did earlier up the thread before taking it apart.

And the one way to prevent these mishaps is to not run the motor too hot, ie. > 200F. Sometimes you may need to replace a bearing instead of (or in addition to) the rotor.

DaveG55

Sometime electric and electronic devices fail for no aparant reason.
Cheap quality componants are most often made with cheap quality materials which are more prone to failure
Wire windings in motors are insulated from each other by a lacquer coating. If that coating is not very uniform then localized overheating can occur - whether or not the entire winding/motor overheats. Cheap wire often has poor qc on the coating and so is more prone to failure.

IMO, that is what has happened to you.
Bottom line, you took a chance buying off brand motors and have suffered a 30% failure rate.

lancer123

i can turn the motor fine

and when i open it up its clean

rotor is not cracked or over heated

i'll post pics later ,..


and can you explain to me

what is the COIL?!

Access

lancer in your case from the ohm-meter measurements it sounds like your motor has a bad coil or bad connection (since not all coils measure the same resistance).

The coil is the wire wrapped around the pole, in brushless inrunners this basically touches the outer can. If something is wrong with a coil, you are probably best off getting a new motor. In theory you can unwind all that wire, get some new wire, rewind it, resolder it, etc., but that is not going to happen irl.

lancer123

pics

http://i159.photobucket.com/albums/t...g?t=1248659324
http://i159.photobucket.com/albums/t...g?t=1248659332
http://i159.photobucket.com/albums/t...g?t=1248659341
http://i159.photobucket.com/albums/t...g?t=1248659351
http://i159.photobucket.com/albums/t...g?t=1248659360


one thing i dont get is

why can all the copper wires INSIDE the can touch each other BUT NEVER SHORT?

is there some clear coat of paint or sumthing on it ?

Aimlessone

The wire is usually epoxy coated.

DaveG55

Great to know that you're reading all the posts in your thread.
I answered that question 4 posts before you asked it.

misasi

The wires have a special coating on them so they dont short out. In one of the pics it looked like there were some blackened windings. There is more than like likely a good chance it got just hot enough to burn away some of the epoxy and short some windings.

gelbschnee

Yes definitely your windings are shorted out. The coating looks charred in some spots. With cheaper materials your motor is more likely to "smoke" as the electronics world calls it. (even if there is no smoke)

lancer123

i read it at 1am in the morning yesterday so i musthave forgotten .

Traxxas4fun

My Feedback: (3)

same thing happened to my castle 4600 motor, except i dont think mine overheated

lancer123

well its not broken anymore


i took it apart and resoldered the plugs and now it works fine ,,

and the

ohm reading are the same as the other motor


lol