CFW-8 filter wheel carousel and Astrodon filters

Discussion in 'Legacy Models - Community Support' started by CrossoverManiac, Sep 24, 2020.

  1. CrossoverManiac

    CrossoverManiac Standard User

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    My Astrodon filters will not go all the way into my CFW-8 filter wheel. It goes in just enough to not have enough clearance for the filter wheel to spin around and it gets stuck. Now, I would contribute that to the Astrodon filters not quite having the same thread thickness except the Astrodon filters screw into other 1.25" filter threads just fine like my ZWO EFW-8 and other filters like the Star Analyzer 100 fits into the ZWO EFW-8 and CFW-8.

    Before I try modding the filter wheel carousel or the Astrodon filters, I'd like to know what the thread size and thickness for the CFW-8 filter slots.
     
    CrossoverManiac, Sep 24, 2020
    #1
  2. Doug

    Doug Staff Member

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    I had a look but couldn't find the old drawings for that part. The specs for the current 1-1/4" threaded filter adapter is M28.5 x 0.6.
     
    Doug, Sep 24, 2020
    #2
  3. Colin Haig

    Colin Haig Staff Member

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    The CFW-8A (about 20 years old) and similar to the CFW8 takes standard 1.25" threaded filters, just like the standard eyepiece thread size, which is metric M28.5 x 0.6 mm pitch.
    It could be that the threads aren't cut deep enough or may not extend high enough and have a bit of a shoulder.
    You may wish to check with a metric thread gauge, and then contact Optical Structures, the owners of AstroDon for advice.
     
    Colin Haig, Sep 24, 2020
    #3
  4. Colin Haig

    Colin Haig Staff Member

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    Colin Haig, Sep 24, 2020
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