benikigai/plus-onePublic

Plus One

Prototype in design. Every value is a design target.

Lessons · Risk

Risk

What could go wrong, and how badly?

12: failure modes
96: top RPN: Battery connector half-seated
0: with RPN 100 or more

RPN	S	O	D	Failure mode	Effect and cause	Operation
96	8	4	3	Battery connector half-seated `fm:battery-unseat`	Dead unit or resets after a drop Cause: Mate force low; in the factory simulation a 2 N tug let half-seated plugs through, so the check is now 3 N Evidence: `src:ec-1-lessons`, `src:factory-engine`	Mate the battery connector
90	6	3	5	Radio check passes a detuned antenna `fm:rf-detune`	Short range in the field Cause: Module antenna near the ring LEDs or the cell Evidence: `src:ec-1-lessons`, `src:module-datasheet`	Functional test: button, touch, ring, haptic, IMU, wired and wireless charge, audio loopback, RF check
80	5	4	4	Stake under-melted; diffuser loose `fm:stake-weak`	Ring rattles; light leaks at the seam Cause: Stake time or temperature low Evidence: `src:tracker-puck-spec`	Heat-stake the diffuser
72	6	3	4	Adhesive bead touches the speaker cone `fm:adhesive-on-cone`	Buzz or low output Cause: Bead placement drift Evidence: `src:design-brief`	Dispense adhesive for the speaker and haptic
72	9	2	4	Battery lead pinched when the base closes `fm:wire-pinch`	Short; heat in the worst case Cause: Lead outside its channel Evidence: `src:ec-1-lessons`	Close the base onto the core
72	6	4	3	Mic gasket off its port `fm:gasket-shift`	Low mic sensitivity; poor wake word Cause: Gasket lifts with the liner Evidence: `src:design-brief`	Place the two mic gaskets over the ports
54	6	3	3	Screw strips the boss `fm:screw-strip`	Board loose; button feel mushy Cause: Torque high or pilot hole oversize Evidence: `src:tracker-puck-spec`	Drive three board screws
45	5	3	3	Coil off-centre in the ring `fm:coil-offset`	Slow or no wireless charging Cause: Coil not keyed to the base Evidence: `src:design-brief`	Place the charging coil and ferrite inside the ring
36	6	3	2	Magnet ring bonded flipped, or a segment missing `fm:ring-polarity`	Won't hold on a magnetic mount or charger Cause: Ring loaded upside down Evidence: `src:design-brief`	Bond the magnet ring into the base
30	5	3	2	Pogo pad recessed `fm:pad-recessed`	Dock or module doesn't connect Cause: Pad not pressed to its stop Evidence: `src:design-brief`	Press the five pogo pads into the base
24	6	2	2	Unit ID provisioned twice or not at all `fm:id-twice`	Twin and QR point at the wrong unit Cause: Retry after a failed flash Evidence: `src:design-brief`	Flash firmware and provision the unit ID
18	3	3	2	QR unreadable `fm:qr-unreadable`	Unit can't open its twin Cause: Laser focus or power drift Evidence: `src:design-brief`	Laser-mark the unit QR on the base rim