# First-article inspection - 28.1 / R3.4

Website version **28.1** = engineering **R3.4 Print Prototype**, prepared 14 September 2026. R3.4 filenames are intentional. This is the R3.3-derived branch; keep it separate from 28.2 and earlier R3.2 A files.

Record inspector/date, printer/nozzle, filament/lot, profile/plate, CAD checksum and measured results. A blank or untested item remains open.

| Check | Result / measurement | Pass / open | Owner / date |
| --- | --- | --- | --- |
| Controls: Measure switch body/terminals, free/operating height, travel and force. Confirm electrical continuity/contact pair, free return at PTT ends and release with case closed. | | Open | |
| PCB and U6: Supplied populated STEP omits U6 solid. Current 24 x 24 x 2.4 mm placeholder supports preliminary clearance only; check corrected populated STEP or physical board, connectors and heights. | | Open | |
| Full harness: R3.3 tested J2 CK reservations and both stock-PH adapter poses conflict; all 12 tested J3/J10 local bend patterns conflict. No complete closed-case harness, common-return branch route or cover-opening slack is validated. | | Open | |
| Battery and USB: Measure actual pack/tape/lead envelope, establish pad behavior and no-pressure retention, verify USB plug seating and approach with the chosen cable. Nominal dimensions are not maximum tolerances. | | Open | |
| Fasteners: Confirm actual head geometry, blind depth, engagement, tapping/fastening method and torque on sacrificial prints; inspect screw tips near battery, wires and controls. | | Open | |
| Optics, sound and RF: Use functional optical material, real mesh/seals and antenna. Validate light output, sound, cellular RF, thermal behavior and durability after assembly. | | Open | |
| Finish / process: Approve actual resin/elastomer or finish samples with RPS. Printed simplifications and integrated caps do not automatically constitute a urethane-casting or metal-machining release. | | Open | |

Additional print observations: support removal damage, seam closure, guide bore finish, cradle seating, minimum-feature reproduction, dimensional error and revisions proposed. Check the PTT at top, center and bottom before and after closing the case. Do not use screw force to overcome battery or wiring interference.

The owner previously reported a good-looking print of an earlier checkpoint. That is not an installed-component measurement or a first-article approval for R3.4. Keep these records separate by revision.