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Similar motor sounds minus the props?

Discussion in 'Pro/Adv Discussion' started by Garrie, Aug 2, 2015.

  1. Garrie

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    I was thinking of making a video of me running the motors without the props attached. And then pushing 100% throttle for each of the 4 directions for each side of the stick.

    For eg.
    Right stick-Up
    Right stick-Right
    Right stick-Down
    Right stick-Left.

    And repeat for the left stick.

    My aim is to record the unique sound each direction generates. I crashed my drone on my 2nd day and always wondered if my motors are damaged.

    If it's a good idea to make this video so that all of us can compare, be it we crashed or never crashed before, and be sure we have the same uniform result, I'll make the video and post it here.

    Let me know if you all think it's a good idea.
     
  2. N017RW

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    Litte to no value.
    You will find with no props the motors will not respond as you expect.
    The FC will be confused as there is no change in attitude and it expects some change to occur because if your command(s).
     
  3. Garrie

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    How bout we compare the sound it makes when it's on ground. Surely it has to be a uniform sound across all phantom 3s?

    My aim isn't to find out how it sounds when it's in the air. My aim is to create a video where everyone can put their drone on the ground and compare the sounds it makes for each direction.
     
  4. III% Streve

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    I get your point in the task, or presented task. But there is no way to reproduce said sound exactly across 2 different people. Much less across ALL people. EVERYONE has something different to produce the sound for comparison.
     
  5. Garrie

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    Hmmm but would that be so?

    If 10 drones were built today and shipped to 10 different locations around the world, and everyone put their drone on the floor in their room and record the motor running, shouldn't the change in motor sound when they change different directions on the sticks be similar?

    After all the production drones should be very similar right?

    The whole point of this topic is that I noticed that different directions produces different sounds. And because I crashed my drone on the 2nd day, I have always been wondering since if any of the motors are damaged or not working as per 'normal".
     
  6. N017RW

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    Garrie, no one is telling you not to do what makes you happy.

    BLDC motors have no moving parts other than bearings so there's very little that can go wrong.

    If it flies fine and after flight all motors are of a similar temp., you're good to go.
     
  7. SteveMann

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    While it may not be a lot of use to other Phantom owners, it could provide you with a baseline. I recommend that you just secure the drone to a flat board to do you runups with props attached. Unloaded motors sound quite different from loaded ones. Your four motors should spin up approximately to the same speed at full throttle. If one of them is a few hundred RPM low, you should replace it. I bought a hand-held tachometer that would work nicely for this, but the frequency of the sound generated by the blades would work as well.
     
  8. N017RW

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    Motor RPM is the 'output' of a closed-loop system utilizing the IMU for feed back to increase or decrease each motor RPM to maintain attitude.

    Their health simply cannot be judged based on RPM alone while the quad is tied to the ground or without props.
     
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  9. SteveMann

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    Not the motors specifically, but this would be the same diagnostic value as a full-throttle runup in my Cessna. If I couldn't achieve 2250 RPM at full-throttle, then a takeoff was out of the question. Something was not right.

    In model aircraft, the max power RPM is a quick diagnostic to determine that there is a problem. The runup RPM should be about the same at full throttle every time, or something is wrong. In my case it was always the motor.
     
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  10. N017RW

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    But now you have 4 motors, electronically commutated, tied into a closed-loop control system where each is individually controlled based the input of the controller and various sensors.

    Not quite the same as pulling on a throttle and checking for RPMs and magneto function.
     
  11. taroh

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    Yes, try leaning front-back-left-right or rotating cw-ccw P3 body with
    > Right stick-Up
    > Right stick-Right
    > Right stick-Down
    > Right stick-Left.
    All sound differs. Actually I use it for "instant check" that IMU/motor is ALIVE/DEAD (not healthy).
    May find one ESC-motor line disconnects, or magnet in the motor broken, or sand in a motor... :)
     
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