FW7 not homing

Discussion in 'Filter Wheels' started by StephenLaurie, Oct 18, 2015.

  1. StephenLaurie

    StephenLaurie Cyanogen Customer

    Joined:
    Jan 23, 2015
    Messages:
    7
    I have a STX-16803 with a FW7 filter wheel purchased through Ian King Imaging. There was a problem with the optical sensor coming off when I tried to put wheel in which has now been fixed. However the filter wheel does not seem to home as it is supposed to.
    The instructions say that on powering up it should move to the second hole of the close pair. My filter wheel just moves about 5 stops and does not select the close pair or calibrate itself on any of the holes. When I try to use it with CCDOPS it will not properly select a filter and gives me an error message.
    However I have got it to work with Maxim. When the camera is first connected in Maxim it again moves about five stops and ignores the holes. However, if I then select a filter position such as 4 it moves and calibrates on a hole. At this stage it is pointing to the wrong filter. But if I then select position 1 it circulates around until it finds the close pair. It is then calibrated and can be used normally.
    I have been imaging like this for a few weeks and it seems to work OK with Maxim although few times I get a "filter wheel" moving message that does not go away. I then have to disconnect the camera and go through the process again from the beginning.
    However I am concerned that there is something wrong with the filter wheel and that it should be homing correctly from power up.
     
  2. Doug

    Doug Staff Member

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    Sep 25, 2014
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    Yes, it should be homing correctly from power up. My best guess is that the sensor isn't aligned properly with the holes. Please inspect the optical sensor and make sure it is installed correctly and in good alignment with the holes.

    (The original FW7 instructions are completely wrong - do NOT remove the wheel when installing the filters. It is not necessary and doing so is very likely to damage the optical sensor. You only need to remove the filter retaining plate. As soon as we noticed this we completely rewrote the instructions.)

    If you can't get it working properly, it may have to be sent in to service.
     
  3. StephenLaurie

    StephenLaurie Cyanogen Customer

    Joined:
    Jan 23, 2015
    Messages:
    7
    I don't think it can be an alignment issue. When I do get it calibrated with Maxim it aligns OK on the holes. It goes slightly past a hole and then moves backwards to the hole. As to whether the sensor looks aligned, I do not know as the filter wheel is new and I have never seen it working properly.
     
  4. Doug

    Doug Staff Member

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  5. Bill

    Bill SBIG Service and Repairs Staff Member

    Joined:
    Oct 12, 2014
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    527
    Yes, that's seems to be the best course of action at this point. I don't think it's a coincidence that it's having troubles finding home after the opto sensor was broken off. Contact me at bill@sbig.com and I'll give you the details on sending it in.

    -Bill
     

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