mohan-bee/gimbal-one-budget-pcb

FABRICATION.md

PCB

Schematic

# Gimbal One budget — prototype fabrication handoff

Use this folder's matching Gerbers, BOM and CPL together. Do not populate the LSM6DS3TR-C on the original ICM board: pins 9/10/11 and local copper differ. Do not mix its BOM with the original Gerber ZIP.

84 × 70 mm, 1.6 mm FR-4, four layers, black solder mask, ENIG. Specify **35 µm minimum finished copper on all four layers**, not a default thin inner-layer stack. Existing thermal/escape vias require filled and capped via-in-pad; have the manufacturer approve that process. Minimum routed signal width 0.15 mm; motor/battery power widths are separately verified in power-width-validation.json. Copper-clearance target 0.10 mm. The 0.20 mm drills / 0.45 mm pads require 0.125 mm nominal annular rings.

There are 65 SMT placements and nine manual parts. All placement orientations are resolved against supplier geometry; approve the supplier preview and verify polarity before production. The CPL and drills use the same lower-left origin. Four mounting centres: (4,4), (80,4), (4,66), (80,66) mm.

U_IMU = **LSM6DS3TR-C / C967633**. JLC lists this as **Standard Only assembly** with X-ray inspection. Ask for a complete quote before deciding this option saves money. Its pads use local 0.05 mm solder-mask expansion and 0.02 mm paste contraction. The narrow mask dams may merge under the manufacturer's black-mask rules; approve the stencil and mask processing with the assembler. Keep the centre underneath the sensor free of top copper; the keepout is included in the source and export.

Read README.md for firmware and physical validation limits. Geometry checks do not establish working stabilization or thermal qualification.