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Old Jan 27, 2014, 05:36 PM
HELICOPTER SWAGG
yours truly's Avatar
United States, FL, Orlando
Joined Dec 2013
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Help!
V912 main motor blown on 7th flight??

Hello everyone, I recently bought a WL V912 and on its 7th flight out of the box my main blades stopped spinning but the tail rotor still spins. Battery was fully charged lights come on servos move and tail spins, but no main rotors. I presume the motor blew but I don't understand... during the 7th flight? Did I get a lemon or could there possibly be another problem? Also, if I need a new motor, do I solder the wires on? Im fairly sure I can take it apart and put it back together and ive watched a video of someone taking it apart, but I dont have much soldering experience, is it very difficult?

EDIT: I forgot to ask if anyone knows a better motor than the stock one that would fit the v912. Brushless might be nice, any recommendations?

sorry this is long I wanted to give full detail and as always I appreciate any help

-yours truly-
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Old Jan 27, 2014, 09:56 PM
Cranky old fart
Balr14's Avatar
Germantown, WI.
Joined Oct 2007
21,338 Posts
It happens. those aluminum frame helis are quite overweight, lots of strain on the motors. You should probably talk to the guys in the Frankenheli thread in the micro forum. They are big on mods and upgrades to this type of heli.
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Old Jan 28, 2014, 09:13 AM
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Quote:
Originally Posted by yours truly View Post
Hello everyone, I recently bought a WL V912 and on its 7th flight out of the box my main blades stopped spinning but the tail rotor still spins. Battery was fully charged lights come on servos move and tail spins, but no main rotors. I presume the motor blew but I don't understand... during the 7th flight? Did I get a lemon or could there possibly be another problem? Also, if I need a new motor, do I solder the wires on? Im fairly sure I can take it apart and put it back together and ive watched a video of someone taking it apart, but I dont have much soldering experience, is it very difficult?

EDIT: I forgot to ask if anyone knows a better motor than the stock one that would fit the v912. Brushless might be nice, any recommendations?

sorry this is long I wanted to give full detail and as always I appreciate any help

-yours truly-
yours truly,

As Bair 14 said in his response, it does happen, although it's kind of rare after only seven flights.

What I would recommend is first check that the plug from the motor at the pcb is plugged in well and making contact. Vibration may have loosened it. Wiggle it while pushing down.

You'll see a red wire loop standing up on the pcb also. Wiggle it and make sure that it's soldered to the pcb well. It's purpose is to protect the motors and their respective fet's from burning out if the rotors are stopped from turning while under power. The fet's basically are the speed controllers for the motors, if I understand their function correctly.

If it's still no go I would order another motor, another pcb and also a tail motor while you're at it from Banggood. Their prices are reasonable although the wait for parts is quite long. I say to also get a tail motor because they usually don't last even as long as the main motor, especially if you do a lot of hovering which really heats them up.

Try the new motor first. If it's still no go then the fet on the pcb is probably shot. The fet is the square piece standing upright in front of where the motor plugs into the pcb. Usually, but not always,if it burns out it will be discolored or have a blistered appearance.

If the motor didn't work you'll have to replace the pcb. Just remember the two second rule when soldering the wires to the pcb so that you don't lift the printed traces off the board with too much heat. Don't let me scare you though: it's really not hard even with limited soldering ability.

Remember not to heat any part for more than about two seconds. If you iron is hot enough that will be more than enough time.

It is possible to put a brushless main motor on, but it's a little more involved. You would need a brushed to brushless signal converter and esc in addition to the bl motor.

I think that there might be a bl kit available for the 912. I seem to think I have read that somewhere.

Good luck. As Bair 14 said, also try the Frankenheli and V912 threads in the Micro Heli forum.
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Last edited by Pa flyer; Jan 28, 2014 at 10:48 AM.
Old Jan 28, 2014, 10:08 AM
HELICOPTER SWAGG
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United States, FL, Orlando
Joined Dec 2013
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Thank you guys 4 the responses. I have checked the pcb board and the plug and they all seem fine. Pretty sure its just the motor, I'm just disappointed at the fact it burnt out so quickly. You would think that the tail motor would go first. I think I'm just going to order a few of each motor and a heat sync for the main motor. I've seen videos on how to install a heat sync and I'm sure it will help the motor last a little longer. Oh yeah, shout out to tailboom terry, his youtube videos are awesome for v912, he did some nice "how to" videos. Again thnx for the replies and happy flying.
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Old Jan 28, 2014, 06:05 PM
HELICOPTER SWAGG
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United States, FL, Orlando
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Update... I ordered 2 main motors and a tail motor (just in case) off Tmart. I also ordered a v911 pro and a whole heli worth of spares for my v911. It was 6$USD for every part minus the pcb and motors. I figure if I could get the motors and pcb for 15$USD or under I can build a v911 cheaper than buying it. Prolly only save 5 or 10 dollars but hey, if u got batteries and transmitter then ur g2g.
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Old Jan 29, 2014, 05:58 AM
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United States, NY
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I consider myself lucky, the motor on my v912 lasted for over 40 flights, and the tail motor seems to be doing just fine. Based on a video I saw I ordered a main motor from an F45. According to the video it's a more powerful motor and a drop in replacement.
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Old Jan 29, 2014, 01:18 PM
HELICOPTER SWAGG
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United States, FL, Orlando
Joined Dec 2013
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Quote:
Originally Posted by Mad Russian View Post
I consider myself lucky, the motor on my v912 lasted for over 40 flights, and the tail motor seems to be doing just fine. Based on a video I saw I ordered a main motor from an F45. According to the video it's a more powerful motor and a drop in replacement.
I have heard of using the f45 motor but I didnt wanna take any chances so I just got the original ones. Also heard of using a v913 motor but if im not mistaken, ive heard the v912 and v913 use the same main motor, so prolly just someone who doesnt know what there talking about. Now all I need is a tip for my soldering iron n ill b good to go when my motors get here. Everything was from US so im presuming ill get them by early next week, if im lucky maybe saturday this week lol.
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Old Jan 29, 2014, 02:03 PM
HELICOPTER SWAGG
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United States, FL, Orlando
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Another update... I found out today I can still return my v912 to amazon and get a whole new one I didn't think I could return it after flying it but apparently I can since I've only had it for 8 days. So ill be getting a new v912 plus my motors so ill have spares to keep it running a while
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Old Jan 29, 2014, 03:48 PM
Seahawks
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United States, CA, Palm Desert
Joined Jan 2014
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My v911 (200 bat) main motor quit after 2 weeks. Motor still works, slowly, if I start it with my finger. Did it quit because I'd fly 7 batteries in a row? Just got a replacement in the mail.

BTW...I found my new motor from a seller in SoCal so only took a few days to get it. Is there a forum on parts stores IN the US? Any large dealers IN the US? Thanks!!
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Old Jan 29, 2014, 04:08 PM
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Ughhhh I wish I had saw this thread before you went and bought more stock motors!

I just installed a 370 super motor (From an ESky CP 3) and it makes a world of difference in flight. Not only that, other than soldering the leads, its basically a drop in mod, and after about 7-8 minutes of flight, the motor is only luke warm to the touch (which means it isn't generating a ton of heat that causes resistance and/or failure).
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Old Jan 29, 2014, 05:09 PM
Seahawks
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United States, CA, Palm Desert
Joined Jan 2014
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370 super motor (From an ESky CP 3)

Hi, Is there a better motor for the v911? Thanks

BTW, Is there a motor upgrade/replacement forum?
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Old Jan 29, 2014, 05:29 PM
Cranky old fart
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Germantown, WI.
Joined Oct 2007
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There's a general "Power Systems" forum. But you won't find much about old brushed motors. They basically only come in a few sizes and are all very cheap and low quality.
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Old Jan 29, 2014, 05:44 PM
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United Kingdom
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Quote:
Originally Posted by Palm Desert Heli View Post
370 super motor (From an ESky CP 3)

Hi, Is there a better motor for the v911? Thanks

BTW, Is there a motor upgrade/replacement forum?
Try here - http://www.rcgroups.com/forums/showthread.php?t=2009496

There's a Guy called Benedikt who stocks a wide variety of small Motors and His prices are pretty good.
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Old Jan 29, 2014, 06:33 PM
Cranky old fart
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Germantown, WI.
Joined Oct 2007
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I was referring to 50, 180 and 370 size motors that are the common ones used in FP helis now.
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Old Jan 30, 2014, 08:45 AM
HELICOPTER SWAGG
yours truly's Avatar
United States, FL, Orlando
Joined Dec 2013
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Quote:
Originally Posted by Palm Desert Heli View Post
My v911 (200 bat) main motor quit after 2 weeks. Motor still works, slowly, if I start it with my finger. Did it quit because I'd fly 7 batteries in a row? Just got a replacement in the mail.
Lol yea id say flying 7 times in a row didn't help. I have 4 batteries for my v911 and I fly one, then let the heli rest at least 5-10 mins b4 I put another battery in. Also I dont fly until the battery dies, I fly just till when ur almost full throttle and the heli is barely hovering. Heard it saves battery life to not fully drain them. But I would definitely let the motors cool between flights

Check out my personal page 2nd thread down. I used bread ties stripped to the wire as makeshift heat-syncs for my v911. Yes I knw real heat syncs are made of aluminum but seems since the bread tie wires are soo small it doesn't affect the motors.
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