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

  • Running Light: 1 W LED Heatsink

    The general idea: a cylindrical holder / heatsink for a 1 W LED on the end of a tube clamped in a Tour Easy fairing mount, much like a flashlight.

    A pleasant evening at a virtual Squidwrench meeting produced the raw shape of the front end from a 1 inch aluminum rod:

    1 W LED Running Light - heatsink raw
    1 W LED Running Light – heatsink raw

    Trace the outline of the LED’s PCB inside the cylinder just for comfort, align to the center, and drill two holes with a little bit of clearance:

    1 W LED Running Light - heatsink drilling
    1 W LED Running Light – heatsink drilling

    For the 24 AWG silicone wire I used, a pair of 2 mm holes 8.75 mm out from the center suffice:

    1 W LED Running Light - heatsink fit
    1 W LED Running Light – heatsink fit

    Gnaw some wire clearance in the lens holder:

    1 W LED Running Light - wiring
    1 W LED Running Light – wiring

    Tap the central hole for an M3×0.5 screw, which may come in handy to pull the entire affair together.

    Epoxy the PCB onto the heatsink with the lens holder keeping it aligned in the middle:

    1 W LED Running Light - heatsink clamp
    1 W LED Running Light – heatsink clamp

    Then see how hot it gets dissipating 900 mW with 360 mA of current from a 2.2 Ω resistor:

    1 W LED Running Light - heatsink test
    1 W LED Running Light – heatsink test

    As you might expect, it gets uncomfortably warm sitting on the bench, so it lacks surface area. The first pass will use a PVC cylinder for easy machining, but a full aluminum shell would eventually be a nice touch.

    A doodle with some dimensions and aspirational features:

    Running Light - 1 W LED case doodle
    Running Light – 1 W LED case doodle

    Even without a lens and blinkiness, it’s attention-getting!