2 motors run VERY HOT

[tezza]

Hi

2 of the front motors now run very hot, ALOT hotter than the back 2. Underneath the motor is very hot as well.
I have had no crash or anything to cause problem. It fly perfectly, hover in spot perfectly. I just notice motor very very hot at end of flight.
Previously all 4 slight warm but now 2 very hot.

Should worry? It has never done before in few month I own. If i spin motors by hand no noise or blockage or anything odd. Motor all seem stable and thing prop connect in middle does not wobble or show sign of damage.

thanks!

 

[slothead]

Has it been windy where you are flying, and are you flying into it? Trying to fight the wind will make at least the ESC's hot and probably the motors as well.

 

[tezza]

No wind tonight. No breeze at all.
Even on very windy day never seen them this hot!!

thank you for suggestion

 

[Mannyx]

Hi

2 of the front motors now run very hot, ALOT hotter than the back 2. Underneath the motor is very hot as well.
I have had no crash or anything to cause problem. It fly perfectly, hover in spot perfectly. I just notice motor very very hot at end of flight.
Previously all 4 slight warm but now 2 very hot.

Should worry? It has never done before in few month I own. If i spin motors by hand no noise or blockage or anything odd. Motor all seem stable and thing prop connect in middle does not wobble or show sign of damage.

thanks!

we have same experience ... after a few flights my motor will no longer spin... i replaced Tiger Motor V3 with Tiger motor Props... i suggest you better buy spare soon... thats the sign for replacement.... the 4 motor has the same temp... not equally the same but more or less should be the same.. hot temp is a sign of abnormality... sorry for my english

 

[CityZen]

The bearings should be the only part of the motors that can wear out, and they are replaceable relatively easily.

 

[tezza]

I back

my DJI dealer replace 2 motor under warranty and install for me. They agree both rear motor run hot than normal.

That happen last month and have been 50 flight since. Phantom fly fine, nice and stable. all 4 motor run nice and cool at same temp.
Over last couple weeks I notice now just 1 of the replaced motor is starting to run hot again. Not hot as before, but still noticable hotter than other 3.
problem motor is rear left if that mean something ?

It seem strange situation brand new motor can have same problem as before ? Phantom still flying nicely, you not notice a problem unless touch motor to compare temp.
could ESC be responsible? If ESC was to blame why it work for few week after replacement ?
i fear shop not help me anymore. How I test ? new motor make no strange noise and spin free like other 3. No notice different from other 3 besides hotter temp.
I have no tip over, no crash, no hard landing.

I welcome test and troubleshoot solution, please

thank you again!

 

[tezza]

Someone please have help ?
Summary: 2 rear motor replaced due to heat problem. run fine after, no temperature issue.

4 week later 1 rear motor that replace start to run hotter than other 3. not hot as original problem before replace, but noticable hotter than other 3.
If bad ESC I thougt problem should not be resolved after motor replacement 4 week ago ?

No crash or bad happening. just start having problem, again

 

[flyNfrank]

Do you have a image showing which arms have which motors installed on them?

 

[justin00]

Im friends with Tez in R/L so know what hes on about.

He had the 2 rear motors replaced.
And the motor getting hotter than normal is Rear left motor if that is what your asking?

We went flying together on monday and the motor does seem significantly hotter than the other 3. Not so hot you dont wamt to touch it but hot enough to warrant some concern.

It spins freely to. The only interesting thing he didnt mention which might be important is the front left motor appears to be a tiny bit sticky, it spins without noise and isnt loose but doesnt spin as freely as the other 3. It doesnt seem to bad though..

Im not really sure how the quads work in terms of flying lol... but could the rear left be getting hotter to compensate for the front left?

Im getting some new motors so will give him mine to test with. Perhaps we replace the front left first and see if that has any effect??

 

[flyNfrank]

I wanted to see if each motor was on the correct arm. If standing behind the quad, the CCW motors are on LF & RR arms.

And he can use a multimeter to check the incoming volts to each motor. Also it is real easy to have the wire sequence wrong on one motor. If all the motors are in the correct position and wired correctly, then I would be looking to replacing a ESC.

 

[burlbark]

If one motor is sluggish the other motors will try and compensate and overheat while that motor will not get hot. Bad esc, bad solder joint to main board, bad motor. I use my thermal unit to test them in real time under load and can watch the specific mosfets get hot. You can also buy a cheap rpm laser and see what motors are dogging down and replace the motor and esc.

Here is a shot of my FLIR I used today to test flight worthiness of a Blade 350qx fight controller.

 

[justin00]

Ya the new motors were put in correctly. He had the hobby shop do it under warranty. We checked the inside and they did a pretty good job, the soldering looks same as factory.
We thought maybe the ESC but for a few weeks after the replacement it was running fine.

We'll plug a multimeter in and measure output under load on all 4 to compare...Would you expect to see higher voltage on the hotter motor ?

Is it possible the rear left is compensating for the front left ?? and the actual issue is the front left ?

That thermal image is very cool!!!
How much does that thermal device cost if I may ask ??

 

[justin00]

Posting on behalf of Tezz... We inspected ESC tonight and did some testing with multimeter.. all seems ok there..
only thing we could see is one of the components on the ESC there a brown 2mm horizontal line going through the middle of it from 1 side to the other.
Its the square component where there is 6 of them beghin the 3 motor wires on each of the ESC.
So each ESC has 6 of these components behind the wires.... and on the motor that runs hot, 1 of the 6 square components has the brown line going through it.

Tried to take a clear pic but very hard to do... might have to zoom in to see the discoloration.. its hard to see with the naked eye as its only a thin light brown line... but definitely has a brown line when you look at it with a torch.

Perhaps that is the cause... ?? Maybe it was done when the motor was replace,i.e got scratched.. all though it brown which leads me to think its burnt possibly ???

 

[CityZen]

That thermal image is very cool!!!
How much does that thermal device cost if I may ask ??

There are a couple that are affordable:
- FLIR One, $250, only for iPhone 5
- Seek Thermal, $200, for Android or iPhone

 

[Fplvert]

I would pull the bell housing off the hot motor and check for magnetic debris stuck between magnets. Even if the motor feels smooth by hand, those little bits can cause drag and even stop the motor suddenly.

 

[msinger]

Fplvert, know of a good way to remove metal bits from a motor?

When I first got my Phantom, I stripped a screw in one of the arms, drilled it out, and got some bits stuck in one of the motors. Had a hell of a time getting them out.

 

[Fplvert]

http://youtu.be/WOHmUeNPGqk
Motor cleaning putty.

 

[msinger]

Putty... genius. Thanks!

 

[Fplvert]

:shock:
That's seriously hot, Dirk!

BTW, you don't have to desolder the motor leads to clean or change bearings. Set a block with a dish towel on it next to the arm you're working on. Watch out for loose C clips and don't lose the thrust bushing under the clip.

 

[justin00]

Are the components im refering to in my pics the mosfets??
Concerning one looks brown/burnt ??

Posting on behalf of Tezz... We inspected ESC tonight and did some testing with multimeter.. all seems ok there..
only thing we could see is one of the components on the ESC there a brown 2mm horizontal line going through the middle of it from 1 side to the other.
Its the square component where there is 6 of them beghin the 3 motor wires on each of the ESC.
So each ESC has 6 of these components behind the wires.... and on the motor that runs hot, 1 of the 6 square components has the brown line going through it.

Tried to take a clear pic but very hard to do... might have to zoom in to see the discoloration.. its hard to see with the naked eye as its only a thin light brown line... but definitely has a brown line when you look at it with a torch.

Perhaps that is the cause... ?? Maybe it was done when the motor was replace,i.e got scratched.. all though it brown which leads me to think its burnt possibly ???