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Weird B behaviour
#1
Good Evening Folks

I have a bit if an odd situation here.  I am sure it is something I have (or have not) done, but damn if I know what it is.  This is kind of a continuation of another thread I recently posted, but the problem is more specific, so I have started a new thread.

I have an older ZMR 250 with a Naze32 rev 6a, Rotorgeeks RG20 ESC’s and Cobra 2204 2300 motors.  I started having some problems with the # 3 motor and I initially thought it was the ESC because of some of its behavior.  Then I noticed an “odd” sound when I turned the motor over by hand, so I opened it up.  Three of the magnets had come unglued and dropped and two more were broken in half.  I tried to repair it (glue the magnets back in) which I have done in the past with complete success.  This time however, the motor had noticeably less power than the other three.  I had a spare so I replaced the motor.  Now here is the weird part……To control rotation back when I built this machine I crossed the leads on two of the motors…..numbers 2 & 3 so they rotated counter clockwise (CCW).  Now I would probably just handle that in BLheli, but I didn’t do this one that way.  So I put the new replacement in, crossed the leads and lit it off……..it rotated in the wrong direction (CW).  Keep in mind I have not even plugged the machine into the BLheli configurator so there is no chance the rotation got switched there.  I did upgrade the firmware on the Naze32, but it operated correctly after I did that before I replaced the motor.  Ok….so just out of idle curiosity, I changed the leads on #3 so they were not crossed.  Any idea what happened?  Yep, I now have CCW rotation on #3.  So the bottom line is that I have three motors with the leads NOT crossed and one motor with the leads crossed and all motors rotate in the correct direction Huh Thinking

As I said, I suspect it’s something stupid I have, or have not done and if anyone could point me in that direction I would be grateful!! Thanks! Smile
"Damn the torpedoes!!!  Full speed ahead!!!"
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#2
I suspect that your spare motor was wound/finished by a different person (maybe in a different factory).  Really don't think it's anything you did (except to trust that all cobra motors are made identically)... Tongue Big Grin
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#3
Yeah....I did think about that, but I ASSuMEd their quality control would be a little better then that. Thanks Scotty.
"Damn the torpedoes!!!  Full speed ahead!!!"
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#4
To be honest i don't really pay much attention to what direction the motor spins by default Big Grin since I can always reverse it the ESC without any soldering.
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#5
The Saga continues......Ok, so I thought I fixed the problem when I replaced the motor....wrong.  When I advance throttle slowly number 3 stutters when starting until I've got a little more throttle into it.  If I start air mode before I take off, it comes up on air mode fine and will work ok from there....until I punch it.  I think the motor is coming up to full speed, but not as fast as the other three.  If I accelerate vertically the left rear of the quad sags but it doesn't continue to rotate....it accelerates evenly but the quad as a list to it so I think the motor is running as fast as the other three, but it takes a little longer (frations of a second) to get there.  So now I am thinking ESC.  The heat shrink is still on but there is no sign of it over heating at all.  So I pulled the top plate so I could get to the wiring a little better and found the following.

[Image: oh4XZ25l.jpg]

If you look closely in the yellow circle the insulation on the signal wires has been melted  (not all the way through).  As you can see, the ESC itself looks fine.

[Image: bj1b83gwires l.jpg]

None of the other ones have this issue.  I would feel pretty confident there was a problem with the ESC (since I already replaced the motor) if the battery leads were melted, but the signal wires carry low voltage and as far as I know minimal current.  Anyone got any ideas? Thinking
"Damn the torpedoes!!!  Full speed ahead!!!"
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#6
Weird... wonder where it could make contact with something hot enough for this to happen? Unless it happened during soldering when you initially built it, which would mean it has always been there and therefore is maybe not the issue, since you said it's not all the way through and the wire is maybe not damaged at all...

Another thing comes to mind though, i've repeatedly seen reports of problems with motor #3 for the recent few versions of betaflight (3.1.x) where it seems it is a DMA / resource conflict, but i'm not sure if this applies to your board. The solution in those cases was to disable sdcard_dma or something like that in cli. But i guess your fc does not have sd card slot at all?
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#7
I wasent  there before.  In fact I THINK that it was where the black and white wire touched because they were twisted together.  Hard to see in the photo, but if I tighten the twist a little the melted area on the white and black wire "fit" together.

Not running bataflight.  This quad is a little over a year old with a Naze32.  Recently when I tried to change some pid values, it gave me a message that I had to upgrade the Naze firmware because the clean flight configurator had updated to 2.0 and was no longer compatible with the older Naze firmware.  So I up graded the Naze and it all worked, but all my settings were toast.  Also, pass though stopped working.  Soooo...since this is just my practice quad, I loaded and older version of Cleanflight (1.2.3) and went back to the original hex file and now all is working ok again....except for this motor/esc thing.  Also, this problem had already started before I started switching things around.  Soooo....I'm still in the dark. Confused  Thanks for the reply!
"Damn the torpedoes!!!  Full speed ahead!!!"
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