As typically happens in FPV, I'm neck deep in some serious blackbox PID tuning ... and a motor goes out completely halting my process in its tracks. I thought it might be interesting (at the risk of embarrassing myself for not finding a solution lol) to document how I intend to go about fixing the issue.
The facts:
* I was following UAV Tech's PID Tuning Principals which necessitates inhibiting much of the Betaflight failsafes such as opening up PID_Sum_limits. This could cause a motor to overheat and get damaged but I was careful to check motor temps each time.
* The problem manifested on the first flight today with motor #3 at first having a hard time spinning up. First arm resulted in a flip. After some tries, I was able to fly fine and actually do some PID tuning. Three or so flights later, #3 really started to act up twitching mid-flight and ultimately crashing the quad. Thereafter it would only twitch intermittently on arm.
* Mechanically, I do notice that #3 is a tad less notchy (these are iFlight motors which horrendously notchy) than the other 3. Mounting and prop screws are not touching windings. Windings themselves look clean. Otherwise the motor shows no physical signs of damage. I do not see any shorts and all exposed terminals have been thoroughly conformal coated.
The plan:
1) Check continuity of iFlight SucceX 4-in-1 ESCs for both + and - at each ESC pad.
2) If #1 shows no continuity, check if it is a software issue:
2a) Run ESCs back at default 24khz in BLHeli.
2b) Remap motors to default X configuration rather than custom dead cat mapping.
2c) Check if RPM filtering load is effecting motor.
3) If software is fine, check mechanical:
3a) Swap motor #1 (works fine) with #3 position.
3b) Swap ESC. Luckily (?) I had destroyed the FC earlier so I was forced to get a new stack so I actually have an brand new ESC of the exact same kind. I am so. lucky. LOL
I am hoping at some point in this plan I can isolate the problem. At best, it's a software issue which requires no additional $$s to fix. At worst, it's a hardware issue where I need to replace the ESC or motor.
Ok wish me luck lol.
The facts:
* I was following UAV Tech's PID Tuning Principals which necessitates inhibiting much of the Betaflight failsafes such as opening up PID_Sum_limits. This could cause a motor to overheat and get damaged but I was careful to check motor temps each time.
* The problem manifested on the first flight today with motor #3 at first having a hard time spinning up. First arm resulted in a flip. After some tries, I was able to fly fine and actually do some PID tuning. Three or so flights later, #3 really started to act up twitching mid-flight and ultimately crashing the quad. Thereafter it would only twitch intermittently on arm.
* Mechanically, I do notice that #3 is a tad less notchy (these are iFlight motors which horrendously notchy) than the other 3. Mounting and prop screws are not touching windings. Windings themselves look clean. Otherwise the motor shows no physical signs of damage. I do not see any shorts and all exposed terminals have been thoroughly conformal coated.
The plan:
1) Check continuity of iFlight SucceX 4-in-1 ESCs for both + and - at each ESC pad.
2) If #1 shows no continuity, check if it is a software issue:
2a) Run ESCs back at default 24khz in BLHeli.
2b) Remap motors to default X configuration rather than custom dead cat mapping.
2c) Check if RPM filtering load is effecting motor.
3) If software is fine, check mechanical:
3a) Swap motor #1 (works fine) with #3 position.
3b) Swap ESC. Luckily (?) I had destroyed the FC earlier so I was forced to get a new stack so I actually have an brand new ESC of the exact same kind. I am so. lucky. LOL
I am hoping at some point in this plan I can isolate the problem. At best, it's a software issue which requires no additional $$s to fix. At worst, it's a hardware issue where I need to replace the ESC or motor.
Ok wish me luck lol.
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