Positioning accuracy of Cyanogen filter wheels

Discussion in 'General' started by Tõnis Eenmäe, Apr 30, 2019.

  1. Tõnis Eenmäe

    Tõnis Eenmäe Cyanogen Customer

    Joined:
    Jan 29, 2016
    Messages:
    1
    Location:
    Tõravere, Estonia
    Hello!

    I'm looking for possible filter wheels for photometry. My previous experience has shown that all filter wheels that use slip rings for movement and Hall sensor for position detection are not very reliable in cool (I mean -20 C in winter) climate nor very accurate. Very old SBIG filter wheel had +-2 mm centering accuracy and rather old Optec one had +-0.2 mm accuracy. That is not very high compared to e.g. former Apogee filter wheels that use physical referencing and that position always with sub-pixel accuracy.

    So my question is - do all Cyanogen filter wheels have physical stops? If yes, is there any play around those stops? Even small play can be important if sensor has small pixels like as it is rather common nowadays.

    Best wishes,
    Tõnis
     
  2. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    6,057
    Not all. These wheels have positive detent:

    FW8S-Aluma
    FW8G-Aluma
    FW8S-STXL
    FW8G-STXL

    Also the now-obsolete:
    FW8S-STT
    FW8G-STT
     

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