The MMM — Magnetorquer Making Machine
Two-axis CNC coil winder for CubeSat air-core magnetorquers, built for Auburn University's small satellite program.
Problem: magnetorquers were being wound by hand. Gaps, overlaps and inconsistent pitch reduce the torque output of the finished coil, and operator-to-operator variation was showing up in test data as noise unrelated to the design under test.
Approach: one stepper turns the coil former (spindle); a second drives a wire guide along a leadscrew (traverse), placing each turn exactly one wire diameter from the last. Turns, layers, wire length and expected DC resistance are computed from the former geometry and measured wire OD before the wind starts; the finished coil is accepted by measuring its resistance against that estimate.
Scope: control PCB (KiCad), 3D-printed frame and controller enclosure (Fusion 360), firmware (C++ / PlatformIO). Gallery runs in build order: mechanical design → electrical design → assembly → troubleshooting → firmware → final build → lessons learned.
