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Thread: tuning. some more help please.

  1. #1
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    Default tuning. some more help please.

    ok, i`ve read the laser fx bit on tuning and this is what i understand so far...

    select your scan rate (30kps i guess cos i have 30k scanners?).
    then display the ilda test pattern(of which there are 2, one full size and one small with a box)
    then set the projector away fron the wall (screen) say 3 meters and measure the width of the projection to get 8deg (using trigonometry??).
    now i get the bits with the low freq damp, high freq damp and servo gain but what about the other pots: input scale, position scale, input offset and linearity?

    any hints guys?

  2. #2
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    of the projection to get 8deg (using trigonometry??).
    now i get the bits with the low freq damp, high freq damp and servo gain but what about the other pots: input scale, position scale, input offset and linearity?


    Dont touch position scale, that invites galvo destruction and is set by factory

    input scale

    You really at first should only be concerned with input scale, low freq damp, HF damp and servo gain.

    You should also have a "quad square" "Laser Media" "30 hertz sqaure" "Grid" and other test patterns, plus the explanation of the ilda test pattern
    ILDA is NOt enough.

    And first, lets evaluate if you really need tuning or just a touch up.
    get out teh full size ilda and set it up for 30Kpps, 8'

    Does the circle just touch the square and is it uniformly touching the square at 4 points. If Not, how much did you have to slow down till it did ? Also what controller are you using and are you sure the PPS reading is accurate?

    Steve

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    thanks for the tips. now how do i set to 8deg?

    i`m using fb3 and live quick.

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    We had a kind of "scanner tuning workshop" at FLEM 1.5. Adam and Aron took good video, and Adam will be cutting the video together and making it some kind of downloadable format. That will probably answer the questions of most people.

    With respect to people trying to undergo their own tuning, the only things I worry about is "which way is increasing" and "which pot is which". Some companies try to keep "which pot is which" a secret... so before anyone tunes a scanner, they should find out definitively which pot controls servo gain, which pot controls damping, and which pot controls high frequency damping. That's critical for success.

    I can say the same about "which way is increasing". American-manufactured scanner amps make complete sense. For example, when you go into your car, or your TV set, or your home stereo, and turn the knobl clockwise, it "increases" stuff (brightness, sound level, etc.). Many Chinese products are the opposite -- not because there was a conscious decision, but because they didn't know it mattered... Also, some scanner amps have some pots which increase as you rotate them clockwise, and other pots that decrease as you rotate them clockwise (on the same amp).

    If you are not careful while doing the tuning, and things get too far out of balance, physical destruction can result!!

    Best regards,

    William Benner

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    cheers for that. i`ll post some pictures to show what i mean. i`m new to the game and thaught "tuning" was a twidle here and a twidle there.
    however i still dont get how you know when you are projecting at 8deg?

  6. #6
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    Use the tan function to get your 8 degrees. There is thread on here somewhere that explains it. Basically, measure distance from your last galvo mirror to the wall and use that for X. Then you tan(a) to solve for Y. (a) is 4 degrees converted to radians... whatever that happens to be. Once you get Y, double it and that is how big (width and height) the square should be on your wall.

  7. #7
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    Quote Originally Posted by carmangary View Post
    Use the tan function to get your 8 degrees. There is thread on here somewhere that explains it. Basically, measure distance from your last galvo mirror to the wall and use that for X. Then you tan(a) to solve for Y. (a) is 4 degrees converted to radians... whatever that happens to be. Once you get Y, double it and that is how big (width and height) the square should be on your wall.
    or just go here

    http://www.pangolin.com/userhelp/scanangles.htm

    Then go here:
    http://www.pangolin.com/ILDAtest.html

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