Attaching New Camera HOW???

Discussion in 'Aluma AC Series CMOS' started by mike shade, Feb 20, 2021.

  1. mike shade

    mike shade Cyanogen Customer

    Joined:
    Sep 14, 2015
    Messages:
    160
    Just received new AC4040 camera/FW7 filter wheel/SC3 Long guider. How do I attach the camera to the filter wheel? It looks like the four black socket head screws on the body of the camera fit the bolt pattern on the camera, but this seems odd. There is the the anodized part in the middle of the camera with four silver screws, this goes to nothing. The other side of the filter wheel bolts to the SC3 easy enough.

    Second question is on back focus:
    Camera .895"
    Filter wheel 1.303
    Guider .87"
    Total: 3.068"

    Is this right?

    Thanks
     
  2. mike shade

    mike shade Cyanogen Customer

    Joined:
    Sep 14, 2015
    Messages:
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    I have even dumber questions, related to question above...
    The camera attaches to which side of the FW7 filter wheel, the side with SBIG on it and connectors or the other side?
    If it attaches to the side without the writing, then it is just a straight bolt up? What about the shims?
    If this is the case, then how does the SC3 long attach to the other side? The bolt patters does not line up?

    I have of course been through the manuals and have not seen this...
     
  3. Doug

    Doug Staff Member

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    Sep 25, 2014
    Messages:
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    First of all have a look at the user guide for the FW7 filter wheel:

    https://diffractionlimited.com/wp-content/uploads/2016/08/fw5-fw7-stx_installation_guide.pdf

    It refers to the STX cameras, but the installation is identical for Aluma AC.

    In short:

    Remove all eight screws from the front of the camera. Note the position of any shims (you shouldn't have to write it down yourself - there will be a shim sheet with the camera).

    There are four screw holes in the bottom of the FW7. Line them up with the outer four screw holes on the Aluma AC.

    Three of the holes in the FW7 can be accessed very easily - just rotate the wheel by hand so an empty filter slot lines up with the hole. Personally I just use three screws as that is quite sufficient to reliably hold the camera.

    If you really want the fourth screw then follow the instructions in the manual carefully. This involves partially dismounting the optical sensor. If you do not follow the instructions exactly, you will damage the filter wheel.

    If you do remove the wheel, do not remove the center spindle bolt, as that will likely result in you returning the wheel for service. There are three bolts that attach the wheel to the spindle - use those.

    Note that the wheel can attach in two orientations, so make sure the filter wheel's cable will easily reach the port on the camera. If not, you've got it the wrong way around so flip it 180 degrees. (I think it will still reach if backwards but it will be at the end of its tether, so to speak.)

    Install the filters, and be sure to reattach the filter retainer plate. Don't overtighten the screws on the plate.

    Reinstall the lid on the filter wheel. Now take the adapter you took off the front of the camera, and reinstall it. Put the shims under the plate exactly as they were on the front of the camera. If you've forgotten their positions check the shim sheet.

    All done!
     
  4. mike shade

    mike shade Cyanogen Customer

    Joined:
    Sep 14, 2015
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    OK, thanks...then the four outer black screws are what hold the camera...I was thrown off as it is a square opening on the filter wheel, the the Aluma is a round opening, it didn't seem quite right. On the other side of the filter wheel is the SC3, and I had Precise Part make an adapter to go into the Optec Gemini on the other end. So assume that the shims are not needed as will not need the adapter?

    Second question is on back focus:
    Camera .895"
    Filter wheel 1.303
    Guider .87"
    Total: 3.068"

    Thanks...
     
  5. Doug

    Doug Staff Member

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    Sep 25, 2014
    Messages:
    9,921
    The shims are for the camera, not for the adapter. If you are using a fast telescope then I would recommend retaining them. You should put them on top of the SC-3.

    You're in the right ballpark. In the downloads section on the camera's product page there is a backfocus calculator spreadsheet.
     

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