The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • Plastic Stress in Polarized Light

    Here’s what the (cracked) faceplate of the FC1002 Frequency Meter looks like, through polarizing filters that reveal the internal stress.

    A circular polarizer screwed on the lens:

    FC1002 Frequency Counter - faceplate - circular polarizer
    FC1002 Frequency Counter – faceplate – circular polarizer

    A sheet of linear polarizing film held in front of the lens:

    FC1002 Frequency Counter - faceplate - linear polarizer
    FC1002 Frequency Counter – faceplate – linear polarizer

    For reference, none of the other instrument faceplates on the bench show anything other than uniform gray, with one exception that points directly to the plastic injection point.

    I’d say this plate cracked due to unrelieved internal stresses and not anything I did or didn’t do.