THOTCON
The May 19-20, 2023 Chicago THOTCON edition whose official schedule documents badge pickup and badge-required party entry, while Rob Rehrig's first-hand maker writeup and Fourfold's portfolio preserve the 0xC electronic badge.
Chicago, Illinois / undisclosed location · United States · 2023
The THOTCON 0xC badge was a Chicago electronic conference badge built around a Contra-inspired, conference-wide laser-tag game and a custom injection-molded clear polycarbonate housing. Rob Rehrig's first-hand writeup documents the badge theme, enclosure work, IR receiver/emitter layout, TIR lens work, Xometry manufacturing path, and roughly 2,000-badge production scale.
Lifecycle
Rehrig describes the 0xC badge theme as Contra and the core functionality as a conference-wide laser-tag game.
The official schedule says attendees needed a 0xC badge for entry to the THOTCON 0xC party at Ravenswood Event Center.
The production path moved from a two-material ABS and PC enclosure concept to a single clear polycarbonate housing so the PCB color and LED passthrough could work within the tooling schedule.
Rehrig documents total-internal-reflection lens work intended to focus emitter output and shape the optical behavior needed for the laser-tag game.
The badge placed an IR receiver in the center and IR emitters on the center-left and center-right of the board for laser-tag interaction.
The first-hand writeup names Xometry as the injection-molding partner and describes design-for-manufacturing tradeoffs around wall thickness, sink marks, lens geometry, and schedule pressure.
Operational history
The record preserves the badge as a real production artifact with mechanical and optical compromises rather than treating the enclosure as a frictionless visual shell.
The United States record remains source-backed and image-free rather than copying source-page media, documentation screenshots, event photos, social media, placeholders, or generated approximations.
The catalogue records verified event, game, mechanical, and optical facts without claiming that the complete design archive is public.