SC-2 Nosepiece Not Fit JMI Focuser

Discussion in 'Guiding and Adaptive Optics - StarChaser and AO' started by Ch Gillespie, Apr 7, 2020.

  1. Ch Gillespie

    Ch Gillespie Cyanogen Customer

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    San Angelo, TX
    Problem with nosepiece furnished w/SC-2 not fitting into JMI Focuser. (All other nosepieces furnished with your equipment as well as others have fit the JMI without problem.) The nosepiece that came with the SC-2 has a small lip (about 7/100” wide) that is exactly 2” OD diameter. Compare to the nosepiece that came with the STF-8300 camera which has a small lip (about 35/100” wide) which is 1/100” less than 2” OD diameter. The problem seems to be that extra 1/100” width of the lip diameter on the SC-2 barrel. I believe if the lip is reduced in diameter a few 1/1000” it will fit into the JMI focuser. I can do that reduction. Question: If I do the reduction, will it void my SC-2 warranty. If so, how can I otherwise get this setup to work?

    The instructions state that “You can optionally use your original T-thread adapter plate instead.” I assume that is referring to the plate that came with the STF-8300. With that plate I could use the nosepiece that came with it which fits the JMI. But, the plate that came with my STF-8300 will not fit the SF-2. The plate has varying thicknesses defined by concentric circles. Outer most thickness is 15/100”; middle thickness is 22/100”; inner most thickness is 31/100”. Problem is with that inner most thickness. That part of the plate bumps against the rectangle shaped box that holds the pick-off mirror. That holds the plate away from the frame of the SC-2.

    Also, I noticed another blog asked about their SC-2 fitting at a 45-degree angle instead of parallel to the STF-8300. Mine fits also at the 45-degree angle. Is this a problem? Thanks… Charlie
     
  2. Colin Haig

    Colin Haig Staff Member

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    Hi Charlie,
    Thanks for reaching out - we'll help you get sorted.

    We had a batch of nosepieces that were a tiny fraction oversize due to a final step in finishing. Unfortunately it seems that we let one of them out the door.
    We can send you a replacement at no charge. Ideally we'd like that one back. Our ISO9000:2015 quality processes are designed to help us deal with these situations.
    If you are in a hurry, you can turn it yourself, that won't void warranty as it's an issue.

    I'm trying to visualize this - if I have it pictured in my mind correctly, I think this is what's going on:
    The plate's thickest concentric circle normally goes inside the filter wheel, so the flat side is toward the SC-2. Flip it over and see if that works for you.

    Are you using an FW8-8300 filter wheel or FW-Spacer without a filter wheel?
    Looping in colleague @Doug for comment.
     
  3. Ch Gillespie

    Ch Gillespie Cyanogen Customer

    Joined:
    Nov 11, 2014
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    Location:
    San Angelo, TX

    Sorry about leaving off the filter wheel information. I am using the FW8-8300 filter wheel. Also, about flipping over the plate. The "back side" of the plate has a lip over the threads for the nosepiece and the nose piece threads can't engage the threads because of that lip.
     
  4. Colin Haig

    Colin Haig Staff Member

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    Ok, thanks for the explanation. I've looped in colleagues.
    We appreciate your patience while we solve this for you.
     
  5. Doug

    Doug Staff Member

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    Yes the 45 degree angle is an unexpected problem. We are planning a change to the SC-2 mounting ring to fix that; however, that will take a while to implement. The fastest way to get you up and running would be to swap out your filter wheel's front plate.

    @Tim can provide RMA instructions.
     
  6. Ch Gillespie

    Ch Gillespie Cyanogen Customer

    Joined:
    Nov 11, 2014
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    Location:
    San Angelo, TX
    Questions: Said you would send me a new nosepiece since the one that came with SC-2 is too big. When will that ship? Also, said "Tim" could provide RMA instructions for filter wheel front plate. If I get the new nose piece, things should work without changing out the front plate. Not sure what I need to do. Please advise. Thanks... Charlie
     
  7. Colin Haig

    Colin Haig Staff Member

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    Just sent a PM.
     
  8. Tim

    Tim Staff Member

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    RMA details sent to PM
     

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