Glen Akins built a fleet of miniature blinking traffic barrels for his desk, and the real story is not the barrels: it is the engineering discipline applied to a small-scale production problem. Each barrel runs a PIC12F1612 microcontroller driving a single LED. Akins calculated that substituting a 555 timer would reduce battery life by approximately 15%, require more passive components, and offer less control over blink timing.
The 3D printed barrel bodies were designed specifically around desktop FDM printer constraints, using multi-part construction and shallow angles to eliminate support material entirely. Akins documents every decision in Fusion 360, making the write-up a functional tutorial on design-for-manufacture at hobbyist scale. The project also produced a second PCB revision and a custom programming adapter board, not because the first version failed, but because Akins was optimizing for repeatability across the whole run.
Read the full write-up at bikerglen.com. The value is not in the conclusion but in watching each subsystem get reworked: the barrel geometry, the component count, the firmware, the tooling. Akins has been publishing this kind of rigorous documentation for over a decade, and this project is among his most complete.
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