Three degrees of freedom without a serial gimbal stack

Design & Engineering: Helios Precision · CubeSat solar pointing · rapid prototyping

Tip, tilt, and heave from one compact parallel platform, designed in Onshape, printed in PLA, wired on the bench, stopped short of powered actuation by firmware.

3× NEMA 17 · A4988 · LDR quad-array · ~600-800 g phase 1 · <400 g phase 2 target

HALO 3-DOF parallel solar pointing platform — SPACE GIMBAL V1, assembledParallel kinematics

Mechanism

The brief was to point a CubeSat solar array across tip, tilt, and heave from base-mounted steppers, without stacking serial gimbals. I designed a three-arm parallel pointing platform, iterated the CAD in Onshape, printed and assembled the PLA frame, and mounted an LDR quad-array for sensing.

Honest scope

Wiring for three NEMA 17 motors and A4988 drivers reached the breadboard. Firmware upload blocked powered tests, so the mechanism remains hand-articulable proof rather than a flown actuator. Along the way I retired a sub-100g mass claim and reclassified the device from a two-axis gimbal story to what it actually is: a three-DOF parallel manipulator with a phase-two mass target under 400 grams.

HALO Onshape CAD — Platform · arm links · motor base · full assembly