muse/book-reading-clip-lamp

mechanical/antenna-fit-notes.txt

LAMP CLIP M7 — EXTERNAL ANTENNA / FRONT BEZEL
08 October 2026. Millimetres. Engineering packaging model, no physical RF test.

PURCHASE
ANT1: Ezurio 001-0014, 2.4 GHz FlexPIFA, 50 ohm, 2 dBi, MHF1/U.FL.
US source: https://www.digikey.com/en/products/detail/ezurio/001-0014/4732758
Primary drawing and installation guide:
https://www.ezurio.com/documentation/datasheet-24-ghz-flexpifa
The maker specifies 40.1 x 11 x 2.5; the detailed drawing gives 40.12 mm body,
41.25 mm width including cable edge and 100 +5/-0 mm overall assembly length.
The cable is supplied with the antenna. Do not substitute 001-0022 (MHF4L).
The model uses the full body envelope; decorative radiator subdivisions are not
an exact reproduction of its internal RF copper. Original drawings are retained
under antenna-drawings; the second image is the related longer-cable example.

CONNECTION
Snap the supplied MHF1 plug onto the connector already on ESP32-S3-WROOM-1U U1.
No RF trace to a GPIO and no second RF socket on the host PCB.
Socket center X=6, Y=19.785 follows Espressif Fig 10-2 and the imported module
position. Z uses 0.8 mm host PCB surface + 0.8 mm module substrate.
The plug envelope uses a 2.5 mm maximum mated height; sample engagement is not
proven by CAD. Pull the plug vertically with a proper tool, never by the cable.

MOUNT / ASSEMBLY ORDER
1. Print rear housing, antenna tray and the revised front bezel for a fit trial.
   Prefer 1.5 mm polycarbonate for the antenna shelf in the RF trial; qualify
   the printed material if retaining a printed tray. No metal-filled plastics
   or metallic paint around the radiator.
2. Clean the flat tray. Peel the supplied antenna adhesive liner; attach the
   ground face flat at X=-20.06..20.06, Y=3..14, Z=7.0. Main element faces +Z.
   Do not flatten the folded element or add tape over its radiating surface.
3. From the open front of the rear cup, insert the populated tray and secure
   its two end tabs with internal M1.6 x 3 pan-head screws. These enter blind
   lands from the PCB side, before installing the PCB. Check pilot fit and
   screw lengths on the actual print; never let a tip puncture the housing.
4. Lay the coax through the feed chase and below the tray, as shown in CAD.
   Its nominal modeled exposed path is 89 mm (100 overall minus 11 body width).
   Supplier length tolerance +5 mm needs loose service slack below the tray,
   secured with nonmetallic tape. Do not cut the supplied coax or wind it over
   the radiator. OD=1.13 mm and minimum bend radius=3 mm are packaging assumptions,
   not supplier-certified limits: measure the sample and confirm the cable limit.
5. Connect U1 before seating the PCB, leaving service slack so the socket is not
   loaded by enclosure handling. Install the PCB, camera assembly and front.
   Three M2 x 16 case screws still enter from the rear only.
6. Antenna access is by removing PCB and the two internal tray screws. The
   antenna is not trapped between permanently closed molded walls.

RF CLEARANCE
Manufacturer rules: >=3 mm nonmetal above main element, >=2 mm along long sides,
>=1 mm behind ground wall; >=10 mm metal above and >=5 mm metal on long sides.
Radiator top Z=9.5; roof inside Z=13.5 -> 4 mm actual headroom.
Adhesive bottom Z=7.0; dielectric tray Z=5.5..7.0. PCB/metal below ground plate
is treated separately from objects above the radiator, as in the maker's guide.
The 3D geometry checks test plastic and metal reservations against enclosure,
harness, hardware, PCB substrate and 108 component envelopes. Coax is checked
against the metal reservation too. This is not an EM simulation or a Wi-Fi test.
The M9 uniform rear roof ends at Z=15.5, with no local antenna or harness bulges.
Do not apply WROOM-1's PCB-antenna keepout to WROOM-1U; it has an external socket.
https://www.espressif.com/sites/default/files/documentation/esp32-s3-wroom-1_wroom-1u_datasheet_en.pdf
Published antenna gain is within the module's 2.33 dBi reference limit, but that
alone does not establish final product compliance or RF performance.
Check return loss/tuning and Wi-Fi operation at required range with camera,
reading light and audio active, in the assembled housing and normal hand pose.

FRONT BEZEL
Face Z=-18 -> -17.2 (0.8 mm reduction). Cup to seam: 14.8 -> 14.0 mm.
Complete printed bezel including internal lip/duct: 16.9 -> 16.1 mm high.
M9 round shell depth: 32.7 mm everywhere, matching the former harness-pocket
maximum. The front bezel retains its M7 0.8 mm reduction.
Lens front stays -16.7: 0.5 mm nominal recess, 0.3 mm with the quoted 0.2 mm
camera body tolerance. The tolerance calculation does not include unknown lens
motion, print tolerance, adhesive or assembly errors: inspect a real assembly.
A local rear relief clears the camera's square corners; minimum local front
floor at that relief is 0.9 mm. Keep the remaining face 1.8 mm thick.
Camera/heatsink/retainer stay in the validated M5 position; 2.415 mm ribbon bend
radius remains unchanged. Diffusers move 0.8 mm with the front face, with the
same printable shape. Microphone tube is shortened to the new face.
Further depth reduction needs a different heatsink/thermal arrangement or a
reworked camera/ribbon mount, rather than just shortening the outside shell.
The existing J2 camera-tail mating mismatch remains a fabrication hold.

REPORTS
geometry-checks.json: manifold parts, fastener seats, collision and bezel checks.
antenna-fit-checks.json: selected antenna, cable length and clearance report.
camera-fit-checks.json: full heatsink envelope and maximum-thickness ribbon.