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Thread: My scanners displaying test pattern

  1. #1
    Join Date
    Dec 2006
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    Default My scanners displaying test pattern

    heres my scanner displaying the ilda test pattern.

    im using the fb3, angle of 50% scan rate of 90%

    im guessing they need tuning??



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  2. #2
    Join Date
    Jan 2007
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    Sheepsville, Wales, UK
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    Default

    Yes they need tuning but the angle is not 50% - 50% is a percentage not an angle. what were you up to in maths class ? What was her name and have you got pictures?
    The angle can be worked out by measuring the width of the scan and the distance between the scanners and the screen. You could get your calculator out and dust off your brain to work it out or.....
    ...go to Pangos page about scan angles - here

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

    Rob
    If you need to ask the question 'whats so good about a laser' - you won't understand the answer.
    -----------------------------------------------------------------------------------------------
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  3. #3
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    Default

    PS on Pango what does scan rate of 90% equate to????

    R
    If you need to ask the question 'whats so good about a laser' - you won't understand the answer.
    -----------------------------------------------------------------------------------------------
    Laserists do it by the nanometre.

    Stanwax Laser is a Corporate Member of Ilda

    Stanwax Laser main distributor of First Contact in UK - like us on Facebook http://www.facebook.com/FirstContactPolymerCleaner
    www.photoniccleaning.co.uk

  4. #4
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    Default

    yeah i know its not the angle, im just a bit lazy to work out the angle
    but i will before the next meet.

    so now the question is, does anyone know what i need to to do tune my scanners. i have original dt40's

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  5. #5
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    Default

    twiddle some pots

    Sorry I dont know which ones do what - maybe Jian can shead a little light?

    Rob
    If you need to ask the question 'whats so good about a laser' - you won't understand the answer.
    -----------------------------------------------------------------------------------------------
    Laserists do it by the nanometre.

    Stanwax Laser is a Corporate Member of Ilda

    Stanwax Laser main distributor of First Contact in UK - like us on Facebook http://www.facebook.com/FirstContactPolymerCleaner
    www.photoniccleaning.co.uk

  6. #6
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    Default

    ummm may pm him.

    which pots do i need to twist? is it the gain ones???
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  7. #7
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    Default

    Im sure there will be a proceedure that will get you the best result and this will involve doing things in a certain order. One thing is clear you have overshoot in the Y axis which with something like medialas microamps will adjust with Low frequency damping. but dont know how that relates to dragon tiger amps

    Rob
    If you need to ask the question 'whats so good about a laser' - you won't understand the answer.
    -----------------------------------------------------------------------------------------------
    Laserists do it by the nanometre.

    Stanwax Laser is a Corporate Member of Ilda

    Stanwax Laser main distributor of First Contact in UK - like us on Facebook http://www.facebook.com/FirstContactPolymerCleaner
    www.photoniccleaning.co.uk

  8. #8
    Join Date
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    Pflugerville, TX, USA
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    Default

    It looks all out of whack. Gain is not right so one side is larger than the other. You also have overshoot. Definitely needs tuning. Do you know which pot is which? That's step 1.

  9. #9
    Join Date
    Dec 2005
    Location
    GuangZhou of China
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    Default

    Hi Andy,
    That problem probably be from "overdriver".
    So the scanner is dead.You can't tune it to work perfection.
    Now you may :
    1.That scanner use for beam show only,no any prblem,you almost can't find where different.just show for animation very bad.
    2.Send to me repair.
    3.upgrade to DT40pro.
    Jian
    http://dtscanner.cn/en/homeen

    DT-40pro scanner
    DT45/50 scanner

  10. #10
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Cool

    I'm working on a scanner tutorial that might help, but it won't be ready for some time yet.

    One thing: remember that most scanners can't display the test pattern at full size (unless you're using the modified pattern that has the very large outer square and then the minature version of the full pattern inside that large square). The standard ILDA test pattern *will* look like crap if you try to display it at too wide a scan angle. (It overdrives the scanners, which can lead to vibration/resonance issues.)

    When tuning, I usually start with the size (or gain) set at around 5 % and then slowly increase it. When you get to the point where the circle in the middle of the pattern stops getting larger, STOP. Back your size off by 1 increment and tune them right there. Depending on the scanners you have you'll probably be at something like 10-15% of full scale, which should correspond to an optical scan angle of between 8 and 20 degrees. (Again, depending on the brand of scanner you have; you need to measure it to be certain.)

    Also, don't start twiddling pots unless you know what you are doing. You can kill your scanners if you let them get away from you.

    Adam

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