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Thread: balancing machine for turbine shaft!!!

  1. #25
    Member neilw20's Avatar
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    Default Phase lag?

    Rik,

    Don't process in real time. You have got no hope.

    I see you said you 'tried' to do it digital. This definitely needs planning and no trial and error stuff.

    In real time, about all you need do is sum the X and Y data, in the correct sign and multiply by 1/speed squared, which filters it, and store in the correct array for each speed interval. Needs heaps of memory.

    Now when you process each speed interval, use percentiles, to toss out the wild data.

    Better still store ALL the RAW data and process it later. You can get rid of wild rubbish better that way.

    Process it ALL LATER, when you apply the brake, if there is one.
    You can't get phase lag if you time tag it properly, which is how it is filtered too.

    A comment: If your web pages were simple, without all the fancy stuff, it could be translated by Babelfish by just pasting the links.
    Be really nice if http://babelfish.yahoo.com/ worked on your web pages. I use it all the time, for non-English stuff, but it won't work past your home page.
    You can't expect a translator to process silly embedded stuff, and a whole heap of your page is lost by the fancy, useless menu stuff.
    It is getting rid of the silly stuff why all my projects work properly.

    Super X3. 3600rpm. Sheridan 6"x24" Lathe + more. THREE ways to fix things: The RIGHT way, the OTHER way, and maybe YOUR way, which is possibly a FASTER WRONG WAY!


  2. #26
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    Default

    You guys should look into this Data processing with DEWESoft 7

    How would you hook up the accelerometers and speed sensor, and or strobe?



  3. #27
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    Default

    When I was building my own balancer, I got many helps and enlightenments from Mr. Miklos Koncz from Hungary, kmiklos@vnet.hu ,
    Hereby his earlier turbine balancer [nomedia="http://www.youtube.com/watch?v=uRHvW_A-DSA"]YouTube - Phoenix Mk4 turbine balancing by Dynams (Original bench)[/nomedia]

    Soft and parts from Mr. Andy Paul,
    Affordable dynamic balancing ,
    got a lot of teachings about dynamic balancing.
    cheers,
    herbert



  4. #28
    Member Khalid's Avatar
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    Default

    Hi Herbert,
    Thanks for the links. Really informative and interesting work.
    Regards

    http://free3dscans.blogspot.com/ http://my-woodcarving.blogspot.com/
    http://my-diysolarwind.blogspot.com/


  5. #29
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    Default Balancer

    Hi

    Lots of info and help with building a balancer and turbines with the GTBA

    GTBA - The Gas Turbines Builders Association

    Built a KJ66,Balancer,Spotwelder etc with the help of these guys

    Ray



  6. #30
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    Quote Originally Posted by neilw20 View Post
    Rik.

    Most of the noise comes from the drive system.
    The old analogue bandpass filter suffers a large phase shift for a small change in frequency. The phase gives you the position which once the Q is high enough to get rid of the noise, the angular error is significant.
    A small angular position, once the balance becomes finer becomes an error at close 90 degrees.

    Don't worry about speed regulation.
    Just spin it fast, release the drive belt and process on the spin down.

    You can use a Kalmen filter Kalman filter - Wikipedia, the free encyclopedia to resolve signals at 0 and 90 degrees, say, call them X and Y.

    I reality you simply multiply the signal by plus/minus 1 at the correct times for 0 and 90 degrees, and save them, along with the current speed.

    sqrt(X^2 + Y^2) gives you the vector for each measuring plane.
    Multiply X and Y by 1/(speed squared), to get rid of the speed problem.

    Stuff all the vectors in and array for discrete speed steps, and process as percentiles, and throw out the wild values caused by silly resonances.
    You need 0 and 90 degrees signals optically from the shaft, and the signals for each measuring plane.


    For this to work it needs to be a high tune system where you measure the unbalance FORCES. Not deflection.
    Piezoelectric transducers against a large mass, work well.
    You can resolve the vector to the balancing plane(s) from the measuring planes by simple moments about the measuring points treating the shaft as a beam.

    I have read at places about wattmetric instrumentation for balancing machines. It is claimed that it given most accurate results. Please let us know more about it, if somebody has some information.



  7. #31
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    Default

    Rik...great work

    http://free3dscans.blogspot.com/ http://my-woodcarving.blogspot.com/
    http://my-diysolarwind.blogspot.com/


  8. #32
    Registered cncadmin's Avatar
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    Default Re: balancing machine for turbine shaft!!!

    Thank You,
    Paul G

    Check out-
    [URL="http://www.signs101.com"]www.signs101.com[/URL]


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balancing machine for turbine shaft!!!

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