iPhone App and mount for checking vibration

Discussion in 'CineStar FAQ - Tips and Tricks' started by Colin Snow, Dec 5, 2012.

  1. Colin Snow

    Colin Snow Active Member

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    You may have seen this elsewhere, but here's a solution to check motor vibration (propellers off!). The check is just a quick visual to see if one vibrates more than the others.

    App is Seismometer 6th
    https://itunes.apple.com/us/app/seismometer-6th/id362472189?mt=8

    Broom handle clips are Crawford #SS28 from Ace Hardware.

    DSC01281_web.jpg DSC01282_web.jpg DSC01286_web.jpg

    Cheers - Colin
     
  2. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Coin:
    I use this Vibration app.
    Nice mounting clip though -- ingenious!

    Andy.
     
    Colin Snow likes this.
  3. Colin Snow

    Colin Snow Active Member

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    Thanks Andy. Yes, I saw that app and didn't get it because it's $4.99. This one is $0.99. So, I kept true to my Scottish heritage. :)
     
  4. Pavlos Antoniou

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    Andy i have the same.. what are the number you get with your motors???

    I take 0.02-0.05 without props..!
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Aye, Jimme....wi' a nam' like Andrew Johnson-Laird, I ken, the noo....
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Pavlos:
    Sorry...don't have the data to hand....I'll try and take some measurements this weekend.

    Andy.
     
  7. Pavlos Antoniou

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    OK thank you...

    If you can put it with a rubber on the boom without gels and etc... as it is..!
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Sure. You have to do that "hard contact" to get any decent reading of the vibrations otherwise the gels, etc. just absorb it.
    It may be this weekend before I have a chance to do this though! Sorry...tight deadline this week.

    Andy.
     
  9. Steve Maller

    Steve Maller UAV Grief Counselor

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    This is ingenious. If I may ask, what does one do with this info if, for example, one motor is vibrating more than others?
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Balance the motor and the propellers in combination. I don't remember the exact technique, Steve, but I did a Google search for:

    balancing motor and propeller​

    Andy.
     
  11. Pavlos Antoniou

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  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Is the "balancing tape" just that vertical strip of black tape, Pavlos?

    Andy.
     
  13. Pavlos Antoniou

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    I use sellotape that is transparent i put small pieces in order to find the point..
     
  14. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Thanks, Pavlos. For the folks on this side of the pond, that's Scotch Tape. ;)
     
  15. Pavlos Antoniou

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    Ok i am w8ing for your measurements

    Thank you
     
  16. Joe Azzarelli

    Joe Azzarelli Active Member

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    From this apps description:
    "
    It acquires and displays time series data, optionally removes DC bias, applies a Hamming window and performs an FFT on each channel to produce frequency spectra"

    Ummm...huh?? ;)
     
  17. Tim Joy

    Tim Joy Active Member

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    I bought the Vibration app and it's definitely worth the 5 bucks. Found a prop that even though it was perfectly balanced, produced 1 g more vibes than the others. That's a LOT when other props were maxing out at .3 - .5 g. (This is g-force not grams btw) This was on an S800 and I hope that CS vibes would be much lower. :)

    I suggest hard mounting it to the boom using the boom clamps and a flat plate. The broom handle holder looks nice but I wonder if it's really making solid contact?
    Also suggest using a tach to read the vibes at the same rpm. A strap under the boom next to the motor will keep it from flying away.
     
  18. Pavlos Antoniou

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    Can you try without prop and tell us how many g you see..

    i am between 0.02 and 0.05
     
  19. Colin Snow

    Colin Snow Active Member

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    Great suggestions. I went ahead and got this app and it is much better at taking samples, snapshots, and making comparisons. I tried several broom clamps and this one is quite snug. The metal plate makes solid contact with the boom and provides enough surface area to hold the phone. I use a rubber band to keep the phone on the plate.
     
  20. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I wonder whether the hold-down strap over the boom alters the vibrations of the boom? Would it be better to have the hold down strap closer to the hub than the iphone? Obviously, the motor would then exert more leverage on the strap so it would need to be stronger...

    Andy.
     

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