Every part, every file
Turn the printed parts round in 3D, see how the boards are laid out, and read the design notes behind them.
Shell · EXO-140…144
Print orientation, as they sit on the bed. Drag to turn, scroll to zoom.
Boards
48 contact boards, every one a different shape: 16 main boards, each stacked on an RP2040 controller, and 32 fillers in the gaps between them. Together they cover 89.5% of the scalp with 1,273 contacts. Each board is only as big as one spring pin allows: the gap from the board to the scalp stays within 2.6 mm across all of its contacts.
Spring pins
No drawings to make and nothing to machine: one off-the-shelf part on every contact. Mill-Max 0919-0-15-20-89-14-11-0: surface-mount spring pin, rounded gold plunger, 9.63 mm free, 3.0 mm stroke to a hard stop, 25 g at first touch, 85 g half-way, 127 g at 2.54 mm. Buy at DigiKey.
Board files
Gerbers, BOM and pick-and-place for every JLC panel, the hub and the camera board: on the bill of materials. Ordering, step by step: ordering one.
Layout studies
How the boards got their shapes: from sixteen squares to boards cut to the head.
