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

  • Tour Easy Rear Running Light: LED Heatsink

    Because the rear running light will have a higher duty cycle than the front light, I made the (admittedly too small) heatsink slightly longer, with a deeper recess to protect the lens from cargo on the rear rack:

    Tour Easy Rear Running Light - boring LED recess
    Tour Easy Rear Running Light – boring LED recess

    Boring that nice flat bottom is tedious; I must lay in a stock of aluminum tubing to simplify the process.

    Drilling the holes went smoothly:

    Tour Easy Rear Running Light - drilling LED heatsink
    Tour Easy Rear Running Light – drilling LED heatsink

    Those two holes fit a pair of pins aligning the circuit plate, with a screw and brass insert holding it to the heatsink. Scuffing a strip across the aluminum might give the urethane adhesive (you can see uncured globs on the pins) a better grip:

    Tour Easy Rear Running Light - circuit plate attachment
    Tour Easy Rear Running Light – circuit plate attachment

    The screw / insert /pins are glued into the plate to permanently bond it to the heatsink. The screw occupies only half of the insert, with the longer screw from the end cap pulling the whole affair together.

    The two holes on the left pass both LED leads to one side of the circuit plate, where they connect to the current regulator and its sense resistor.