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Thread: Mirror mirror...takes a fall ?

  1. #1
    Join Date
    Jun 2007
    Location
    Monroe, Mi USA
    Posts
    818

    Default Mirror mirror...takes a fall ?

    Well...I noted I would manage to screw other things up !!! While attempting to improve my nearfield alignment....I believe I got my one and only bounce mirror...smudged with a small fingerprint.
    So...mm....I followed the suggestions on PL...and Edmund Optics....and used Acetone and a dry optical tissue to clean the optic. The optic is an Edmund A43-532 Visible Laser Diode Mirror. It is a second surface mirror...not a very expensive one....@ 17.50 USD....with 97%reflectance @ 45DEG.
    Well, this cleaning method is a bitch !!! Optic secure...place tissue on surface...a few drops of Acetone....and slowly drag the tissue across the
    surface. The Acetone evaporates....leaving a clean surface....well almost !!!
    It takes alot of practice to get just the right speed of the drag !!!! Wrong speed...gives you a series of lines !!! Anyway...finally got this down...and it was looking OK. Put the mirror back in the holder....fired up the Greenie ....all good!!! Later that evening.....I noticed a possible smudge on the back side of the same mirror....so I said...mmmm....I'll practice on that side too!!! Possible mistake !!!!
    Now....when the Greenie is turned on....there is an very faint, elipitical
    shadow centered around the green beam....a rather large shadow too !!!
    When you loosen and rotate the mount....the beam and shadow track together !!!
    I speculate that the coating was damaged by my cleaning the back side !!
    DUHHHHH !!!! The Edmunds app.notes say; " The surface of a bare aluminum coating should never be touched "...Oh...I touched it allright!!
    I coulda had a 17.50$ CIGAR instead !!!!!
    Has this happened to anybody else ???????????? or do I get the DumDum
    prize by myself ???
    CDBEAM /BoB
    Beam Axiom #1 ~The Quantum well is DEEP ! Photons for ALL !!
    .
    Beam Axiom #2 ~Yes...As a matter of fact...I DO wear tinfoil on my head !!
    .
    Beam Axiom #3 ~Whe'n dout...Po ah Donk awn et !!
    .
    Beam Axiom #4 ~A Chicken in every Pot, and a Laser Lumia in every Livingroom !!
    .
    Beam Axiom #5 ~"Abstract Photonic Expressionism"....is "Abstractonimical" !!
    .
    Beam Axiom #6 ~ "A Posse ad Essea" ~ From being possible to being actual ...is the beam target !

  2. #2
    Join Date
    Sep 2006
    Location
    St. Louis, MO - US
    Posts
    83

    Default

    No, you're not the only one. I've destroyed more coatings and glass using acetone by soaking things in it...not a good idea. I "try" (key word) to keep my fingers off optics, but sometimes we just goof and smudge things.

    The worst I ever did was blowing out one of my smaller Schmidt-Cassegrain telescopes out with 70 psi of air. I removed the corrector plate and blasted away...the baffle tube/mirror slide mount is coated in lubricant so the mirror can travel up and down smoothly...

    Well - guess what comes off that tube...all the oil and grease...where does it go…….directly on the mirror.

    That was a $400 mistake. I'm glad I learned that on a less expensive model than on the telescope that cost me $6,500.


    Don't feel bad - hopefully you've taken something away from this experience and will remember it next time.


    Phil

  3. #3
    Join Date
    Jun 2007
    Location
    Monroe, Mi USA
    Posts
    818

    Default Keepa Ya Hanz OFF !!

    Phil,

    The title sez it all !!!. To those of us...whom were unlucky enough....to be " Genetically Predisposed " to F'ing with things....when we should know BETTER...to leave well enough alone....I say this : I salute you !!! AND feel your PAIN !!!

    I also wonder....should I pop for a " better " bounce mirror...more durable ??such as the precision optical flat ...1/4 wave, 25.4mm dia, Enhanced Aluminum, Edmund Stock # A32-634....@ 55.00 USD...?????
    or....just stick with the more economical ones...and not give the metallic coatings....mmmm...an acetone " scrub a dub, dub "...DUH !!

    NO....I'm not poppin for the High precision one @ 1219.00 USD ( #A48-111)....where does the madness end ???????......NOWHERE !!! NEVER !!!
    Well...thanks for letting me know....I am in good company !!!

    CD SMUDGED BEAM !! BoB
    Beam Axiom #1 ~The Quantum well is DEEP ! Photons for ALL !!
    .
    Beam Axiom #2 ~Yes...As a matter of fact...I DO wear tinfoil on my head !!
    .
    Beam Axiom #3 ~Whe'n dout...Po ah Donk awn et !!
    .
    Beam Axiom #4 ~A Chicken in every Pot, and a Laser Lumia in every Livingroom !!
    .
    Beam Axiom #5 ~"Abstract Photonic Expressionism"....is "Abstractonimical" !!
    .
    Beam Axiom #6 ~ "A Posse ad Essea" ~ From being possible to being actual ...is the beam target !

  4. #4
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Cool

    Bob;

    If you want a replacement mirror, check out these mirrors from all electronics.com. They're only $12 each, and they reflect 99% of visible light from 488 nm to 694 nm! Awesome deal...

    Adam

  5. #5
    Join Date
    Jun 2007
    Location
    Monroe, Mi USA
    Posts
    818

    Default Wow ! $75 mirror for $12

    Wow Adam,
    Great find....New Newport mirror...Newport wants $75 ...All-Electronic wants $12....I'm game...I'll try two (2) !!! 99% reflectance !!!
    THANX !!!!!!!
    BoB
    Beam Axiom #1 ~The Quantum well is DEEP ! Photons for ALL !!
    .
    Beam Axiom #2 ~Yes...As a matter of fact...I DO wear tinfoil on my head !!
    .
    Beam Axiom #3 ~Whe'n dout...Po ah Donk awn et !!
    .
    Beam Axiom #4 ~A Chicken in every Pot, and a Laser Lumia in every Livingroom !!
    .
    Beam Axiom #5 ~"Abstract Photonic Expressionism"....is "Abstractonimical" !!
    .
    Beam Axiom #6 ~ "A Posse ad Essea" ~ From being possible to being actual ...is the beam target !

  6. #6
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Cool

    Don't thank me... Thank Carmangary. He's the one that originally found those mirrors for just $12. I bought 4 of them back then, and I might just stock up on a few more... Nice things to have!

    Adam

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