SBIG FW8G-STXL Self-Guiding Cover

Discussion in 'STX and STXL' started by blackdragon72, Jun 17, 2019.

  1. blackdragon72

    blackdragon72 Standard User

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  2. Doug

    Doug Staff Member

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  3. blackdragon72

    blackdragon72 Standard User

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    Gerat!

    What is the total backfous with OAG cover, with 3" thread adapter?

    Another question is whether 16200 use the same 12V car power adapter as STL11000?

    Thanks
     
  4. Doug

    Doug Staff Member

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  5. blackdragon72

    blackdragon72 Standard User

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    I plan to use it on FSQ106ED F/5. Now the question is whether 72mm (scope side) to 3" (camera side) adapter will have vignette problem for self guided filter wheel? The adapter will be ~30mm thick.
     
  6. Doug

    Doug Staff Member

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    This took a lot of number crunching, so you'll definitely want to check my math!

    I've attached a section view of the assembly. The location of the pick-off mirror is approximately shown (as it is adjustable) in blue. The inside edge of the mirror can be moved in as far as 12 mm from the center - which would no doubt cause vignetting on the sensor. It can also be moved so far out that your adapter will vignette it severely. Let's see how a middle position might work.

    section.jpg
    By my calculations, the top of the pick-off mirror is about 14 mm below the flat part of the dovetail. That puts your 72 mm restriction about 44 mm higher. An f/5 beam reduces by 8.8 mm diameter in this distance, so at the top of the guider pick-off mirror the beam will be 72 - 8.8 = 63.2 mm in diameter, or 31.6 mm radius. So the mirror will need to be moved in closer than 31.6 mm to see starlight. No problem doing that so let's consider how far we can move it in without vignetting the main CCD.

    The KAF-16200 is 21.6 mm tall, so it extends to 10.8 mm from center line on the short side where the pick-off mirror is. The top of the pick-off mirror is approximately 51 mm above the chip. At f/5 that will bring it in by 51 / 2 / 5 = 5.1 mm.

    So if we set the mirror at 10.8 + 5.1 = 16 mm from the centerline, it won't vignette the main CCD. That's a lot less than 31.6 mm. So if my numbers are correct it sounds like you can get the mirror into a position where you don't have much if any vignetting.

    Please do check my math though!
     
  7. blackdragon72

    blackdragon72 Standard User

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    I just received self guided filter wheel. However I am seeing a couple of issues already.

    First the locking screw is too short to lock the mirror and sensor. I contacted Bill and he is going to send me a replacment.

    Another problem I am facing is that comparing to my standard FW cover, the self guided has an extra half-circle hole for I2C cable. While in my system, the same hole is on the FW base, not the cover.
    From attached image, you can see a big gap round I2C cable, which could cause light and moisture getting into the FW.
    Did you change the design to move the hole from base to cover? Do you have any rubber plug to plug the hole in the cover?
     

    Attached Files:

  8. Doug

    Doug Staff Member

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    Apparently the knob supplier slightly changed the design, without any warning, resulting in the screw seating further into the knob. That is why it is too short. We have a way to mitigate that. We are also enhancing our QA inspection procedures to look out for this sort of issue going forward. Bill is sending you a replacement.

    We're looking into the cover gap issue.
     
  9. Doug

    Doug Staff Member

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    For the gap at the cable entry we have a simple solution.

    We have a plastic cap that fills the hole in the top plate and helps hold the cable down. It has to be glued in place. If you like we can send you the cap and you can install it yourself, or you can send the wheel over to Bill @ SBIG Service & Repair and he can do it for you.
     
  10. blackdragon72

    blackdragon72 Standard User

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    Great! I can install it if it is simple.
     
  11. Doug

    Doug Staff Member

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    I'll ask @Colin to help you with that.
     
  12. Colin

    Colin Staff Member

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    PM Sent blackdragon72
     
  13. blackdragon72

    blackdragon72 Standard User

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    Colin,

    Thanks, but I have got more problem to sort out first.

    Doug,

    I tried guiding last night and this morning, but self guider did not pick up any signal.

    PHD2 can connect to either main sensor or guider sensor.
    When connecting to main sensor, the image looks good, and images is clearly different if I cover the scope in daytime (ie, brighter if I uncover the scope, and dark erif cover the scope).
    However when connecting to guider sensor, the image is always black, looks like there is no signal at all even uncovering the scope.

    I tried difference HDMI cable, remained the same.

    So does it mean guider sensor is DOA? Or could it be electronics issue in Main camera?
     
  14. blackdragon72

    blackdragon72 Standard User

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    And is there any way for me to pinpoint the issue?
     
  15. Doug

    Doug Staff Member

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    You can't communicate with a single camera from two different programs, so PHD probably isn't going to work for you.

    There is a selector in the STXL cameras for internal/external guide sensor (there used to be internal guide chips in previous camera models... software feature is still there). If you can't select that you might not be reading the correct sensor.

    I'd suggest trying it with CCDOPS first, or get the MaxIm DL Pro demo from our web site and try that.
     
  16. blackdragon72

    blackdragon72 Standard User

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    I used only one program -PHD2 - when trouble shooting. PHD could see main CCD and internal guider and connect either one, are you saying it was not correct, it should have been external guider?
    I think SGPro has option to set to internal guider or external guider. It also has ASCOM driver for SBIG to solve "access guider from different program" problem.

    I will try CCDOPS.
     
  17. blackdragon72

    blackdragon72 Standard User

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    If I understand correctly, PHD2 was trying to access "internal guider" which is not present in current 16200 model, so PHD2 can not access remote/external guider.
     
  18. Doug

    Doug Staff Member

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    I'm not really familiar with the functionality of PHD2.

    The software should be able to access the "external guide head". The electronics are built into the STXL camera; it's just the sensor itself that is "external". If you are getting a blank image you are probably not selecting the correct guide head.

    Please also make sure that your camera drivers and firmware are up-to-date using SBIG Driver Checker. (If you are running a version of Driver Checker that is more than a couple of years old, we strongly recommend downloading the latest version of SBIGDriverChecker instead of using the Update button, because we've improved the driver checker itself. The software can be downloaded from the product page for your camera model.)
     
  19. blackdragon72

    blackdragon72 Standard User

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    Found the below information from PHD2 manual.
    Setting SGPro to remote guide head fixed the issue. Looks like PHD2 does not support remote guide head, so it has to team up with SGPro.

    Support for SBIGDual-chipCameras

    Many cameras fromthe Santa BarbaraInstrument Group (SBIG) havetwo sensors - a primary onefor imaging and asecond, smaller onefor guiding. Whilethetwo sensorsare physically separate, they shareelectronics insidethecameraand moreimportantly, shareasingle USBdata link to thecomputer. This means that downloading of datafromthetwo sensors must becoordinated - you can't retrievea guider image whilean imagefromthe main sensor is being downloaded. Beyond that, Windows will only allowoneapplication atatimeto connect to thecamera over thesingle USBlink. Theseare physicaland architecturalrestrictions thatcan't becircumvented by PHD2. However, it is possiblefor thecameracontrolling (imagecapture)application to implementan interfacefor PHD2 to get datafromthe guidechip - essentially,a"side door"mechanism that won't violateany oftheaboverules. With thisarrangement, theimagecaptureapplication isacting asatrafficcop to coordinateaccess to the two camerasensors. At thetime ofthis writing (October 2015), the only imaging application that does this is Sequence Generator Pro (SGP). If you use SGP as your main imaging application, you can also usetheir"SGP API Guider"module, which allows PHD2 to access the guidechip on the SBIGcamera
     
  20. blackdragon72

    blackdragon72 Standard User

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    Now one last problem (I hope) is that if I extract sensor all the way out (turn the sensor knob clockwise), the sensor assembly will interfere the FW, so FW can not rotate. I am not sure which part of sensor assembly causes the issue, it might be PCB board since it sticks out a little. The problem disappears if moving sensor in (maybe a few mm). It is not an issue for me since I dont need to extract sensor all the way out but it is something you want to check and fix.
     

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