Filter Cartridge Progress

While waiting for focuser pieces in the mail, I’m working on the filter cartridges:

A few new features. First, chamfers around the edges. Second, finger holes at the top to help with screwing/unscrewing filters. Third, pattern on the triangular corner to help with grip and distinguish cartridges (and therefore filters) in the dark. Cartridges will come in six corner configs:

  1. smooth on top, smooth sides
  2. smooth on top, indented sides
  3. ridges on top, smooth sides
  4. ridges on top, indented sides (shown)
  5. indented top, smooth sides
  6. indented top, indented sides

This allows for 6 pairs of filters that can be distinguished in the dark without a flashlight.


  1. Azri on September 1, 2019 at 2:46 am

    … and to remember which filter went into which cartridge… 🙂

    • Analog Sky on September 5, 2019 at 6:02 am

      Yes, this evolved into just creating labels that glow in the dark:

      This way you don’t have to remember which is which!