Limonchito working document, published as-is. Prices and lead times are estimates from September 2026 and change often.
Lemon – sourcing and logistics plan (2 prototype rounds + 500-unit batch)
Status: 2026-09-17. Buyer: Gerrit, NL workshop, acting as a business (KvK + BTW number needed first: 1NCE sells B2B only, and B2B VAT reclaim needs it).
Sources: the overnight research agents (transcripts in .claude-personal/.../cfa6c1fe.../subagents/), plus re-checks today for the Qi puck, the replaceable cell and the closure hardware.
How to read prices - "live" = seen on the supplier page or in a search result on 2026-09-16/17. ESTIMATE = not verified, needs a quote. - EUR ex VAT unless marked "incl". FX (ECB, 16 Sep 2026): EUR/USD 1.1537, EUR/GBP 0.8574. USD prices are converted at that rate. - Quantities used throughout: - Prototype round 1 (R1): 10 lemons (5 pairs) → 12 boards, 5 cradles' worth of test pucks. - Prototype round 2 (R2): 10 lemons, production-intent → 12 boards. - Production (P): 500 lemons + 5 % = 525 boards / 525 cells / 1,050 domes, 250 pairs + 5 % = 263 cradles and boxes. - Spare cells (Battery Reg. Art. 11(7), 5 years): 200 cells, bought in two batches of 100 (see §4).
Decisions this plan follows: user-replaceable cell on a keyed 2-pin connector; cradle = passive leaf shell around an unmodified CE-certified Qi puck; boards fully assembled by JLCPCB (except wire-lead parts, see §2); PU skin cast in the NL workshop; rev B adds LED + accelerometer.
0. Summary
| Phase | Total (≈, see §9) |
|---|---|
| Prototype round 1 (10 lemons) | €1,970 |
| Prototype round 2 (10 lemons, production-intent) | €2,060 |
| Production (525 lemons, 263 cradles, packaging) | €37,800 (lean variant ≈ €31,400) |
| Equipment (one-off) | €2,580 |
| Total | ≈ €44,400 – plus compliance (≈ €46k expected) this is well over the €50k goal |
Longest lead / supply risks: nRF9151 (0 stock at DigiKey and LCSC, 16 wk), Würth RX coil (161 in stock, 26 wk → qualify TDK alternate), BQ51013B (26 wk) and LIS2DW12 (24 wk) factory leads, production cells (UN38.3/IEC 62133-2 + DG freight), Chinese New Year ≈ 6 Feb 2027.
Do this week: register KvK/BTW; ask for a 525-pc nRF9151 allocation; buy 24 nRF9151 + all 161 Würth coils; pre-order LCSC parts into the JLC library; request cell certificates and samples; buy the 4 test pucks.
1. Electronics (per board)
Primary distributor is DigiKey NL (EUR, ships DDP from the US, free shipping ≥ €75, ~3 days, 21 % VAT charged at checkout – reclaim it on the BTW return; reverse charge not offered, ESTIMATE). LCSC parts can be fitted by JLCPCB directly from their stock, which avoids consignment. Mouser/Farnell/TME were not reachable by the agents, so their figures are ESTIMATE.
"Route" column: JLC = JLCPCB fits it from LCSC stock or JLC global sourcing; CONS = buy it ourselves and consign to JLC (or JLC global sourcing); NL = ships to the workshop, fitted by hand (wire-lead or mechanical parts).
| Ref | Part / SKU | Supplier (primary / backup) + URL | € @20 | € @525 (break) | MOQ / pack | Stock (16–17 Sep) | Factory lead | Route | Notes / risk |
|---|---|---|---|---|---|---|---|---|---|
| U1 | Nordic nRF9151-LACA-R7 (LTE-M SiP) | DigiKey 24713453 / Mouser / LCSC C22397843 / Rutronik24 | €17.45 (10+ DigiKey); Mouser $22.78 @1 ≈ €19.75 | €14.10 (500, T&R) | cut tape from 1; reel 100 (-R7) | DigiKey 0, 100 due 20 Nov 2026; Mouser "in stock" (search snippet, unconfirmed); LCSC 0 | 16 wk | CONS or JLC global sourcing | Top risk. Ask Nordic sales NL / EBV / Rutronik for a 525-pc allocation this week. Prototypes: buy 24 at Mouser now. JLC's own listing is PCBA-only and needs X-ray. |
| U3 | TI DRV2605LDGSR haptic driver | DigiKey 5014144 / TI.com / LCSC | €1.45 | €1.08 (500) | reel 2,500 | not shown (DGST variant 195) | 16 wk | JLC | Confirm stock before ordering; buy 550 at the first order. |
| M1 | Vybronics VG0832012 LRA Ø8×3.2 mm, 235 Hz | DigiKey 7364317 | €2.43 | €1.98 (500) | trays of 100; factory direct only ≥2,000 | 1,958 | 9 wk | NL (wire leads) | Alternates in stock: VG0832013D (same, adhesive, 2,628), VG0832022D (929). |
| U4 | TI BQ51013BRHLR Qi receiver | DigiKey 5142996 / LCSC C55663 | €2.64 | €2.07 (500); LCSC $1.95 ≈ €1.69 | reel 3,000 | DigiKey 5,352; LCSC 1,101 | 26 wk | JLC (LCSC) | Enough stock today; a 26-week lead means buy the 550 at R1 time, not later. BQ51013C exists – do not swap without checking. |
| L2 | Würth 760308101214 Qi RX coil, 26 µH, Ø19×0.8 mm, wire leads | DigiKey 5725359 / Mouser / RS 163-1888 | €6.01 | €4.51 (192, highest break) | tray | 161 | 26 wk | NL (wire leads) | Cannot cover 525. Buy all 161 now, qualify the TDK alternate in R1/R2. |
| L2-alt | TDK WR222230-26M8-G, 27 µH, Ø22×0.9 mm | DigiKey 445-173093-ND | €2.44 (10), €2.13 (50) | ≈ €1.70 ESTIMATE | – | 8,216 | 10 wk | NL | DCR 1.1 Ω (2× Würth); needs 22 mm keep-out and a small retune (≈97 → 94 nF). Saves ≈ €1,500 on 525. |
| U5 | Microchip MCP73831T-2ACI/OT charger | DigiKey 1979802 / LCSC C424093 | €0.65 | ≈ €0.54 ESTIMATE; LCSC $0.46 ≈ €0.40 | reel 3,000 | 44,561 / LCSC 2,030 | 10 wk | JLC | Low risk. |
| U6 | TI TPS62849DLCR buck, fixed 3.4 V | DigiKey 10445066 | €1.36 | €1.01 (500) | reel 3,000 | 15,784 | 9 wk | JLC / CONS | Package is 8-pin VSON-HR (DLC), not WSON – check the footprint. |
| U2 | Same Sky NSIM-2-C nano-SIM socket | DigiKey 21796984 | €0.52 | €0.39 (500) | reel 1,500 | 11,248 | 8 wk | CONS / JLC global sourcing | Low risk. |
| U7 (rev B) | ST LIS2DW12TR accelerometer | LCSC C189624 / DigiKey 7348326 | $1.05 ≈ €0.91 (LCSC 10+) | $0.76 ≈ €0.66 (LCSC 500) | reel 10k, no MOQ at LCSC | LCSC 15,406; DigiKey 1,671 | 24 wk | JLC (LCSC) | Chosen over ADXL367 ($5.12 @500) and BMA400 (out of stock until Dec). Pre-order ~600 into the JLC parts library now. |
| D1 (rev B) | Kingbright APHHS1005SYCK 0402 yellow LED | DigiKey 1747822 | ≈ €0.17 ESTIMATE | ≈ €0.09 ESTIMATE | reel 2,000+ at $0.08–0.09 | 81,256 | 7 wk | JLC | Alt: APHHS1005SECK amber; Lite-On LTST-C191KSKT 0603. |
| Y1 | Epson FC-12M 32.7680KA-AC0 32.768 kHz, 9 pF | DigiKey 6217649 | €0.49 | €0.39 (500) | T&R 1,000 | 10,859 | 20 wk | JLC / CONS | Removed in rev B (ELECTRONICS_REVB.md: clocks are inside the SiP). Don't order for production; buy 5 for R1 only if the first boards show clock trouble. |
| J1 (rev B) | JST GH BM02B-GHS-TBT 2-pin 1.25 mm, latching, top entry | LCSC C161690 / DigiKey 807800 | DigiKey $0.32 ≈ €0.28 | LCSC from $0.076 ≈ €0.07 (live snippet) | reel | in stock (LCSC, DigiKey) | 16 wk (JST) | JLC | Recommended over JST SH (SM02B-SRSS-TB, $0.234 @1k, 82,160 stock): GH has a positive latch and survives repeated user swaps; both are keyed. Cell side: GHR-02V-S housing ($0.10) + SSHL-002T-P0.2 crimps, fitted by the cell maker. |
| ANT | Kyocera AVX 1004795 LTE-M SMD antenna 36×9×3.3 mm | DigiKey 11694166 | ≈ €2.51 ESTIMATE | $2.14 ≈ €1.85 (500) | reel | 5,000 | 9 wk | JLC / CONS | Nothing off-the-shelf covers bands 20/8/3 in 30×6 mm. R1 prototypes this and the Taoglas FXP40 side by side. |
| ANT-alt | Taoglas FXP40.07.0085A flex 42.6×12.1 mm, U.FL, 85 mm cable | DigiKey 4965530 | ≈ €4.80 ESTIMATE | ≈ €3.50 ESTIMATE | – | not checked | – | NL | Also: Ignion NN02-224 chip (12×3 mm, $1.07 @1k, 67,281 stock) needs a long ground plane. Custom 30×6 mm FPC at JLC: ≈ $25–45 for 25, $0.25–0.50 each at 550 (ESTIMATE) – poor band 20. |
| SW1/2 | Snaptron F12450 12 mm 450 gf 4-leg dome, 2 per unit | Snaptron F12450 (sales@snaptron.com) / sister part F12340 on DigiKey Marketplace | free samples (pay shipping) | ≈ $0.28–0.35 ≈ €0.26–0.30 ESTIMATE (F12340 is $0.274 @1k) | ≈ 500–1,000 ESTIMATE | F12340: 193,700 | 2–4 wk ESTIMATE + FedEx 3–5 days | NL | US origin: duty ≈ 2.3 % + VAT ESTIMATE. Order 1,100 in R2 timeframe. Alt: Snaptron GX12550 (550 gf). |
| – | Passives (~35/board: 0402 caps/resistors, 3× 10 µF 0603, Murata DFE201610E-2R2M 2.2 µH, 2–3 RF match parts) | LCSC basic parts via JLC / DigiKey | ≈ €2.00–2.50 DigiKey; ≈ €0.30 JLC basic ESTIMATE | ≈ €0.50 DigiKey; ≈ €0.20 JLC basic ESTIMATE | – | Samsung CL05A475 1.3 M; DFE201610E 90,759 | DFE 21 wk | JLC | Use JLC basic parts wherever possible; only the inductor and RF parts are "extended" ($1.53 feeder fee each). |
| – | Murata RF matching kit (0402 LQW15 / GJM15) | DigiKey | ≈ €100–250 once ESTIMATE | – | – | – | – | NL | One-off tuning with the NanoVNA (§6). Not in the unit BOM. |
| SIM | 1NCE IoT Lifetime Flat, Card Business 3-in-1 (punch to nano) | 1nce.com pricing | €13 (€12 + €1 card) | €13 | none; B2B only | – | delivered 2–3 business days (DE) | NL | 10 yr / 500 MB / 250 SMS; reverse charge with VAT ID. The 10-year clock may start on the order date – order production SIMs close to shipping and confirm with 1NCE. Test SIMs: the nRF9151 DK ships with Onomondo + Wireless Logic SIMs. Backup: Onomondo (free 5-SIM trial), emnify/Soracom by quote. |
Electronics cost per board (parts only)
| Build | Per board | Notes |
|---|---|---|
| R1/R2 (qty-20 breaks, nRF from Mouser) | ≈ €44 + SIM €13 | nRF €19.75, Würth coil €6.01, FXP40 €4.80, passives €2.25, rest ≈ €11 |
| Production, Würth coil, 1004795 antenna | ≈ €29.8 + SIM €13 | nRF €14.10 is 47 % of the parts cost |
| Production, TDK coil, JLC basic passives | ≈ €26.7 + SIM €13 | saves ≈ €1,600 over 525 |
Parts buying route to JLCPCB
- LCSC-stocked parts (BQ51013B, MCP73831, LIS2DW12, LED, GH header, passives): let JLC fit them from stock. For the 525 run, pre-order them into your JLC parts library now (JLC "parts pre-order"), so they are not sold out when production is ordered.
- Not at LCSC (nRF9151, possibly NSIM-2-C, TPS62849, DRV2605L, crystal):
- JLC global sourcing: JLC buys from DigiKey/Mouser for you; 9–20 business days; no shipping charge; prices "slightly different" from the distributor; some part types carry 3–30 % duty or a $20 inspection fee (JLC). Best for R1/R2.
- Consignment: ship reels to JLC Zhuhai; customs clearance ≈ $45 (<5,000 CNY) / $85 (>5,000 CNY), 2 % handling (min $10), $0.142/pc extra for loose parts, send attrition extras (JLC). Best for the 525 nRF9151s if you secure an allocation from Nordic/EBV yourself.
- Wire-lead and mechanical parts (LRA, RX coil, domes, antenna if flex, cells) ship to NL and are fitted in the workshop, per ASSEMBLY.md.
2. PCB fabrication and assembly (JLCPCB)
Board: 4-layer, 1.0 mm FR4, 44×26 mm custom outline, ENIG, both sides populated, ~40 unique parts, 0.5 mm LGA (needs X-ray). Plus 2 dome carriers per unit (12.5×12.5 mm, 2-layer, castellated, no parts), panelised.
JLC Standard PCBA fee card (live, jlcpcb.com/help/article/pcb-assembly-price): - Setup $25.56 single side / $51.12 double side; stencil $8.21 / $16.42 - Feeder loading $1.53 per extended part type (was $3 until Dec 2025) - Joints $0.0016 each (≤ 50k), min $0.48 per board - X-ray $1.64/board at 1–10, falling to $0.082 at 3,001+ - Fixture $8.21 (1–29 boards: $16.42); panel fee $8.21 - PCBA itself: "90 % within 24 h, 48 h max" after fab
| Item | Supplier / URL | R1 or R2 (12 boards) | Production (525) | Lead time | Notes |
|---|---|---|---|---|---|
| 4-layer bare board, ENIG, epoxy-filled & capped vias, ±10 % impedance, 1.0 mm | JLCPCB quote | $99.60 calculator (engineering $25, via fill $16.98, ENIG $17, impedance $32.84, board $2.90; quantity setting not certain) ≈ €86 | ≈ $197 calculator ≈ €171 (ESTIMATE: the agent's quantity selection was not captured) | 3–4 days | PCBWay check: $62.28 @20 (4–5 days) and $180.97 @525 (6–7 days), HASL, no impedance, + DHL $26–37 – backup only. |
| Standard PCBA, double side | JLCPCB | setup 51.12 + stencil 16.42 + fixture 16.42 + ~15 extended × 1.53 + 12 × (0.48 joints + 1.64 X-ray) ≈ $132 ≈ €115 | setup/stencil/fixture/feeders ≈ $107 + 525 × (≈ $0.48 + ≈ $0.25 X-ray ESTIMATE) ≈ $490 ≈ €425 | 1–2 days after fab; + 9–20 business days if global sourcing | Eurocircuits (BE, no import) and Aisler (DE) quote only via their calculators – not priced; useful only as an EU fallback. |
| Dome carrier panel, 2-layer, castellated | JLCPCB | $62.10 calculator (castellated $39, ENIG $17, engineering $4, board $2.10) ≈ €54 | ≈ €80 ESTIMATE (more panels, same fixed fees) | 3 days | Castellation needs routed edges → panel with mouse bites, not V-cut. |
| Shipping JLC → NL | DHL Express | ≈ €20–30 ESTIMATE | ≈ €60–100 ESTIMATE | 3–5 days | B2B: since 1 Jul 2026 every B2B import needs a formal declaration; PCBAs HS 8517.79 = 0 % duty; 21 % import VAT (reclaimable); DHL disbursement fee 2 %, min €15 (with account). |
| Round total | ≈ €280 per prototype round | ≈ €780 | ≈ 1–1.5 wk (parts at LCSC) / 3–5 wk (global sourcing) | Excludes parts in §1. |
3. Charging cradle: certified Qi puck in a passive leaf shell
The cradle holds an unmodified, CE-marked, WPC-certified puck; we add only a printed/cast leaf shell. The puck's own CE and Qi certificates stay valid because it isn't opened. The Lemon + puck pair still gets tested together for EN 303 417 (see COMPLIANCE.md). Ask the reseller for the puck's EU DoC and keep it in the technical file.
Earlier research into bare transmitter boards (Adafruit #2162, Renesas P9235A-RB, Würth 760308111 TX coil – out of stock, 22 wk) is dropped with this decision. Large retail pads (Anker 313 ≈ 99×99×10 mm, Belkin WIA012 Ø102×11 mm, IKEA SJÖMÄRKE on a 24 V adapter) do not fit a 90×60 mm leaf.
| Model | Size | Input / cable | Adapter in box | Cert | Price (retail, live) | Price @20 / @263 | Fit / risk |
|---|---|---|---|---|---|---|---|
| Samsung EP-P2900BBEGWW "Qi2 25W Magnet Wireless Charger" (recommended) | 55.5 × 55.5 × 4.4 mm, 52 g | USB-C, fixed 1.5 m cable | No (-TBEGWW variant bundles a 45 W adapter) | Qi2 (Qi 2.2) certified, CE | €28.49 (aio.lv), €40.32 incl (eparts.fr), €44.99 (Euronics LV) | ≈ €35 incl / ≈ €22–26 ex VAT ESTIMATE via a B2B distributor (e.g. ATRIA Europe, Samsung Business) | Thinnest and smallest found; fits a 90×60×12 mm leaf. Fixed cable, so no separate USB-C cable to source. |
| Belkin BoostCharge Pro Qi2 15W pad WIA011 (backup) | 60 × 60 × 13 mm | USB-C, tethered 2 m cable | Yes, 20 W (a variant without PSU exists) | Qi2 certified | $29.99 with PSU (Belkin) | ≈ €30 / ≈ €20–24 ex VAT ESTIMATE (Belkin B2B) | Has a pop-up stand; 13 mm thick pushes the leaf to ≈ 16 mm. |
| Generic Qi-certified OEM puck (Alibaba) | ≈ Ø55–60 × 6–8 mm ESTIMATE | USB-C | optional | only if the exact model is listed in the WPC database | – | ≈ €6–10 @263 ESTIMATE, MOQ ≈ 500 | Verify the WPC listing and real RED/EMC/LVD reports, not just a CE sticker. Could save ≈ €4k. |
Must be tested in R1: - BPP fallback. Qi2 (MPP) chargers must support Baseline Power Profile (5 W) receivers (EDN), but the Lemon's BQ51013B has no magnet ring and sits ≈ 3.3 mm off the surface, and some Qi2 pads behave badly with older receivers (Android Police). Buy 2 Samsung + 2 Belkin for R1 and measure charge current, alignment tolerance and heating. - Magnets. The puck's magnet ring pulls on steel parts (domes, LRA can). Check that the Lemon doesn't snap or rattle and that foreign-object detection doesn't trip.
USB power adapter: don't include one. 5 W BPP charging runs from any USB-C phone charger. The cradle isn't a listed category under the Common Charger Directive 2022/2380 (ESTIMATE; COMPLIANCE.md agrees). Bundling an adapter adds ecodesign (Reg. 2019/1782) paperwork and ≈ €3–4 (white-label) or €10–15 (branded) per set. Print "USB-C adapter not included" on the box.
Leaf shell: cast in Smooth-Cast 300 + So-Strong Green (≈ €0.75 material/unit, §5) from a silicone mold on an SLA master. Alternatives: SLA in-house ≈ €1.80–2.50/unit; MJF PA12 at JLC3DP ≈ €3–6 + shipping (grey/black only). All ESTIMATE.
4. User-replaceable battery and closure hardware
4.1 Cell: 602025-class LiPo, PCM, JST GH 2-pin lead
Requirements (COMPLIANCE.md §0, §2): a model-specific IEC 62133-2:2017 report, UN38.3 test summary, MSDS/SDS, same cell + PCM part number as tested; keyed connector; published replacement spec.
| Supplier | Part | Spec | Certificates | € @20 | € @525 + spares | MOQ / lead | Notes |
|---|---|---|---|---|---|---|---|
| LiPol Battery Co. (Shenzhen) – primary, lipobatteries.net LP602025 | LP602025 | 270 mAh, 0.999 Wh, 6×20×26 mm, 5.4 g, PCM + 50 mm wires; max charge 135 mA | Site claims IEC 62133-2:2017, UN38.3, UL, CB, MSDS (live, not model-specific) | samples ≈ €6–10 incl. connector ESTIMATE | "$499–599" per pack of 100/200 → ≈ $3–5 ≈ €2.60–4.30/pc ESTIMATE; GH lead + label ≈ +$0.20–0.40 ESTIMATE | packs of 100/200; ships ≤ 7 business days; DHL/UPS/FedEx 3–7 days | Get the IEC 62133-2 report and UN38.3 summary for LP602025 with this PCM before paying. Max charge 135 mA → MCP73831 charge current ≤ 0.5 C. |
| EEMB – backup, eemb.com | LP602025 (270 mAh, 6×20×25 mm, PCM) | same class | Company lists UL1642, IEC/EN 62133, UN38.3, KC, PSE | ≈ €5–8 ESTIMATE | ≈ €2.50–4.00 ESTIMATE | MOQ 5 from stock (1 wk); new production 6–7 wk | Model-specific IEC 62133-2 not confirmed – ask. |
| Ampul.eu (CZ) – R1 only | Li-Pol 250 mAh 602025 | 25×20×6 mm, PCM, bare wires | datasheet only | €6.23 ex / €7.54 incl (live, in stock) | – | EU stock, road parcel | No IEC 62133-2 → prototypes only; add a pre-crimped GH pigtail. |
Quantities and cost (planning figure €3.50/cell incl. GH lead, ESTIMATE): - R1: 15 Ampul cells + GH pigtails ≈ €120. - R2: 20 LiPol (or EEMB) samples with GH lead, production-intent, DG courier ≈ €220 ESTIMATE. - Production: 525 cells ≈ €1,840 + spares batch 1 (100) ≈ €350 + DG air freight ≈ €300 ESTIMATE + 2.7 % duty. - Spare cells for 5 years: 200 in total. Assumption: ≈ 40 % of 500 users replace once (a lightly used LiPo ages out in ~2–3 years). Buy 100 with production and 100 around 2029 from the same supplier and model, so shelf-aged stock isn't sold. Store at 40–60 % SoC, ~15 °C. Batch 2 (≈ €350 + freight) is outside the launch budget.
Inbound cell shipping (China → NL): - Loose cells ship as UN3480 (PI965): air needs DG handling and ≤ 30 % SoC. DG express (DHL/FedEx) ≈ 5–10 days, ≈ €150–400 per shipment ESTIMATE. Sea/rail (30–45 days) is cheaper but too slow here. - Duty HS 8507.60: 2.7 % (live) + 21 % import VAT; formal B2B declaration. - Register as battery producer with Stichting OPEN: €0.038/cell ≈ €20 for 525 (live).
Outbound spare cells: PostNL refuses loose cells. Ship spares by a DG-contract courier (DHL Express Section II surcharge €5/shipment, live) and price that into the spare.
4.2 Board-side connector
See J1 in §1: JST GH BM02B-GHS-TBT (LCSC C161690 ≈ €0.07; DigiKey 807800 $0.32 @1). Cable side: GHR-02V-S housing ($0.10, DigiKey) + SSHL-002T-P0.2 contacts, crimped by the cell maker. Backup: JST SH SM02B-SRSS-TB + SHR-02V-S-B ($0.234 @1k / $0.10).
4.3 Closure: 2 screws (recommended) or twist-lock + O-ring
COMPLIANCE.md allows a tool-free twist-lock or 2 standard screws.
| Item | Supplier (primary / backup) | Price | Qty (P + protos + spares) | Line € | Lead | Notes |
|---|---|---|---|---|---|---|
| M2×5 pan-head Torx T6, A2 stainless, ISO 14583 | NL/DE fastener shop (e.g. ERIKS, Würth NL) ESTIMATE / Westfield Fasteners UK / AliExpress 100-packs | ≈ €0.04–0.08 each ESTIMATE | 1,200 | ≈ €70 | 2–7 days | UK sources add import VAT + clearance fee. |
| Brass heat-set insert M2 (ruthex RX-M2x4) | ruthex.de / 3DJake | 70 pcs $8.52 ≈ €7.40 (live) → ≈ €0.11 each | 1,200 (≈ 17 packs; ask for a bulk price) | ≈ €130 | 2–4 days (DE) | Heat-setting into brittle SLA resin can crack it – test in R1. Fallbacks: bond the insert with resin, or self-tapping plastic screws (≈ €0.05, ESTIMATE). |
| Alternative: NBR 70 O-ring 32×1.5 mm for a twist-lock cap | o-ring-stocks.eu ORS2676 (MOQ 140) / ERIKS shop NL | ≈ €0.10–0.20 ESTIMATE | 600 | ≈ €90 | 2–5 days | Size depends on the rev B core – confirm with the mechanical stream first. |
Budget used in totals: ≈ €200 for production, ≈ €25 per prototype round.
5. Skin casting, cores and consumables
EU suppliers (no duty, 1–5 days): FormX (Amsterdam), Syntec (Dordrecht), KauPo (DE; its prices may be net or gross – confirm), VEVOR EU. Avoid UK (Mouldcraft): import VAT, likely 6.5 % duty on US-made PU, 2 kg max size.
Legal: EU diisocyanate training (Reg. 2020/1149) is required before professional PU use – free online course. Opened PU keeps ≈ 6 months; blanket opened cans with dry gas (XTEND-IT ≈ €25 ESTIMATE).
| Line | Product | Supplier + URL (primary / backup) | Prototype buy (per round) | Production buy | Stock | Notes |
|---|---|---|---|---|---|---|
| Skin PU 70A | Polytek PT Flex 70 (1:1, 4–5 min pot life, 2 h demold) | Syntec NL | 2 kg €42 (live, "from") | 10 kg ≈ €150–180 ESTIMATE, ×2 | not shown | Fast cycle; pour 2–3 molds per mix. |
| Skin PU 70A (alt) | Smooth-On PMC-770 (2A:1B, 30 min working, 16 h cure) | FormX 10.89 kg / KauPo | KauPo 1.36 kg €58.35 | FormX €281.50 ex / €340.62 incl (live) ×2; KauPo €349.30 | FormX: 1 | Forgiving but slow (≈ 11 days for 525). Choose after R2; the budget uses PMC-770 (dearer). |
| Pigment | So-Strong Yellow 56 g (+ White) | KauPo / FormX | €23.56 (live) | 3 yellow + 1 white ≈ €95 | – | White pigment blocks the LED – test the window in R1. |
| Mold silicone | Mold Star 30 (platinum 30A) | FormX 7.98 kg / KauPo | Syntec Eurosil 33 2 kg €59 (live) | FormX €245.90 incl (live) ×2 | FormX: 3 | Platinum can fail to cure on SLA masters: post-cure + seal, test first. Fallback FormSil 25 tin-cure 20 kg €337.59 incl (FormX, live, in stock). |
| Release | Ease Release 200 340 g | KauPo / FormX | €20.99 (live) | 3 cans ≈ €63 | – | Extends mold life. |
| Cradle shell resin | Smooth-Cast 300 7 kg + So-Strong Green | FormX 7 kg / KauPo (green €26.43) | R2: 7 kg €149.96 incl (live) | 2 × 7 kg ≈ €300 + green €26 | in stock | ≈ €0.75/shell. |
| Core halves (SLA) | Siraya Tech Blu (≈ €0.55/half) or Formlabs Tough 2000 (€175/L ex, ≈ €1.75/half) | 3dpartnershop / siraya.tech EU; Lay3rs | 1 kg ≈ €50 | ≈ 12 kg Blu ≈ €700 | 3dpartnershop out of stock | The printing resin doubles as UV glue for the halves. |
| UV torch | Convoy S2+ 365 nm | AliExpress | ≈ €25 ESTIMATE (R1 only) | – | 7–15 days | Alt glue: Loctite AA 3491 25 ml ≈ €35–50 ESTIMATE. |
| PET discs 14 mm | 3M 850 tape 25 mm × 66 m, 50 µm | shop-sks.com / Tapespoint | 1 roll €56.76 incl (live) – covers all phases | – | – | + 14 mm hollow punch ≈ €15 ESTIMATE. |
| LED light path | Clear PMMA rod Ø3 mm × 2 m | PerlaPlast (in stock) | ≈ €5 + ≈ €12 long-parcel fee ESTIMATE | 3 rods ≈ €30 | – | Alts: Clear Flex 50 second shot, Bivar PLP2 ($0.47–0.67). |
| Consumables | Nitrile gloves (no latex near platinum silicone), cups, sticks, IPA 99.9 % 5 L (€29–36), sandpaper | softnitrilhandschoenen.nl / FormX / bol.com | ≈ €60 ESTIMATE | ≈ €200 ESTIMATE | – | IPA ships as ADR limited quantity. |
Casting materials per phase (incl VAT): R1 ≈ €330, R2 ≈ €400, Production ≈ €2,350 (PU €681, silicone €492, pigment €121, release €63, Smooth-Cast €326, SLA resin €700, consumables €200, rods €30). PT Flex 70 + FormSil 25 instead saves ≈ €500.
6. Equipment (one-off)
6.1 Programming and test
| Item | Supplier (primary / backup) + URL | Price | Stock / lead | Notes |
|---|---|---|---|---|
| nRF9151-DK | DigiKey NL 24420446 / Mouser / Glyn | €87.69 ex (live) | 151 in stock | Also the production programmer via its Debug-out header (free). Ships with Onomondo + Wireless Logic SIMs. |
| Power Profiler Kit II | DigiKey NL 13557476 | €91.86 ex (live) | 1,493 | Battery-life work. |
| J-Link (optional) | J-Link BASE Compact via SEGGER / TME | ≈ €400–450 ex ESTIMATE | – | Not the EDU Mini (€63.28): its licence forbids commercial use. Skip unless the DK is too slow for 525 units. |
| NanoVNA-H4 (antenna tuning ≤ 1.5 GHz) | AliExpress ≈ €55 (snippet) / Eleshop ≈ €70–90 ESTIMATE | ≈ €70 | – | LiteVNA 64 €144.59 ex (Eleshop) covers up to 6.3 GHz. |
| Bench supply Korad KA3005PS | Eleshop | €95.59 incl (live) | – | Replaces KA3005P. |
| Multimeter UNI-T UT61E+ | TME / bol.com (unavailable) | ≈ €55–70 ESTIMATE | – | Brymen BM235 ≈ €130. |
| Pogo test fixture (DIY) | P75-E2 probes + R75-2W receptacles, AliExpress 100 receptacles $9.80 + printed jig + FR4 | ≈ €30–60 ESTIMATE | 2–3 wk | Mill-Max 0906 is a spring contact, not a probe. Pro fixture (Ingun/Merifix NL) ≈ €800–3,000 – not needed. |
| Qi reference pads | the R1 pucks (§3) | – | – | – |
| Subtotal (no J-Link) | ≈ €450 ex VAT |
6.2 Electronics workshop
| Item | Supplier + URL | Price | Notes |
|---|---|---|---|
| Soldering: Pinecil v2 + 65 W USB-C PSU | Eleshop | €40.57 incl (live) + ≈ €25 | Hakko FX-951 is retired (€289 ex). JBC CDB ≈ €450–550 ESTIMATE if you want a pro station. |
| Hot air Quick 861DW | quick-global.eu | ≈ €260.76 incl (snippet) | Atten ST-862D ≈ €150–200 ESTIMATE. |
| Hot plate Miniware MHP30 | Welectron / Opencircuit NL | €95 (snippet) / €142 | Rework only (30×30 mm). |
| Microscope Andonstar AD409 Pro | andonstar.com | ≈ €200–280 ESTIMATE | Stereo AmScope SE400 ≈ €250–350. |
| ESD mat + earthing plug + wrist strap | Eleshop mat | €29.95 incl + ≈ €15 | – |
| Fume extraction Hakko FA-400 | Eleshop / RS | ≈ €90–120 ESTIMATE | Weller Zero Smog EL ≈ €462 ex. |
| Consumables: paste, flux, wick, tip cleaner, IPA | Eleshop / TME / Reichelt | ≈ €60–80 ESTIMATE | Paste needs a fridge. |
| Subtotal | ≈ €890 incl VAT |
6.3 Casting workshop
| Item | Supplier + URL | Price | Notes |
|---|---|---|---|
| Vacuum chamber 19 L + 3 CFM pump | VEVOR EU / FormX degassing system €322.59 | €161.90 (live) + oil ≈ €10 | For silicone. |
| Pressure pot 20 L + compressor 24 L + regulator | VEVOR NL 20 L (10 L €113 is out of stock) | ≈ €120–160 + ≈ €100–150 ESTIMATE | Fits ≈ 2–4 stacked 8-cavity molds. |
| Scale KERN EMB 3000-1 (3 kg / 0.1 g) | De Weegschalenshop | €135 ex / ≈ €163 incl (live) | Needed for 2:1 PMC-770. |
| SLA printer Elegoo Saturn 4 Ultra 16K + Mercury Plus 2.0 wash/cure | Elegoo EU | €449 promo / €649 list + €104–149 (snippets) | Formlabs Form 4 €2,625 ex (Lay3rs) only if tolerances demand it. |
| Respirator 3M 6000 half mask + A2P3 filters | Veek.nl | €59.47 incl (snippet) + spare filters ≈ €25 | Required for PU pouring. |
| Subtotal | ≈ €1,240 incl VAT |
Equipment total ≈ €2,580 (≈ €450 ex + €2,130 incl VAT).
7. Packaging and outbound logistics
Retail set: 2 lemons + leaf cradle (puck with fixed USB-C cable) + manual card, box inner ≈ 160×110×50 mm. Box and print prices sit behind configurators the agents couldn't read, so most are ESTIMATE – get quotes in R2.
| Line | Supplier (primary / backup) + URL | @20–30 | @263 | MOQ | Lead | Notes |
|---|---|---|---|---|---|---|
| Printed mailer box (retail + shipper in one) | Packhelp custom mailer box / Pixartprinting | ≈ €4–6 ESTIMATE | ≈ €1.20–1.80 ESTIMATE | 30, any size (Packhelp claim) | ≈ 10–15 working days + 2–5 days | Packhelp snap-lock product box is €0.72 @300 (live) but custom sizes need MOQ 1,500 – only if a standard size fits. EU B2B: reverse charge. |
| Insert (die-cut cardboard or EVA foam) | Packhelp inserts / NL foam converter (Schuimrubbershop) | €2–5 ESTIMATE | €0.40–1.00 card / €0.80–2.00 foam ESTIMATE | 50–100 | 1–3 wk | Molded pulp needs €1–3k tooling – no. Needs a DXF from the mechanical stream. |
| Manual card A6 / A5 folded | Drukwerkdeal / Helloprint / Printdeal | €15–30 ESTIMATE | €30–60 total ESTIMATE | none | 2–5 working days | Must carry CE, WEEE bin, battery symbol + replacement instructions URL, manufacturer address (GPSR), simplified RED DoC, bands + max power. No "Qi" logo on our own product. |
| Outer postal box (if the mailer isn't used as shipper) | Rajapack.nl postdoos (sizes 180×130×60, 250×150×60) / Superdoos | from €0.27 ex (live) | ≈ €0.30–0.45 | packs | ships within 24 h | Letterbox parcel ruled out (32 mm limit). |
| Prototype boxes + sticker labels | Rajapack + Helloprint / Stickermule | ≈ €15 + €30–60 | – | – | 1–5 days | R2 only. |
| GS1 barcode | GS1 NL | €37 one-off + €28/yr (live) | – | – | – | Only if selling through retailers/bol.com. |
Packaging per phase: R2 prototypes ≈ €85; production ≈ €1,020 (mailer €395, insert €370, manual €45, outer boxes €105, void fill €40, GS1 €65).
Outbound postage (PostNL, rates from 12 Jul 2026, live): NL parcel to door €7.45 online / business ≈ €7.40 (100–250/yr); klein pakket €5.85–6.35; Germany/France/Spain ≤ 2 kg €12.50. Lithium: allowed in equipment, max 2 batteries per device per shipment – one pair per parcel is fine; no loose spares. Sendcloud/MyParcel ≈ €4–5 NL ESTIMATE. 250 NL parcels ≈ €1,850 – normally charged to the buyer, so kept out of the batch total.
EPR fees (live): Stichting OPEN battery fee €0.038/cell (≈ €20), WEEE €0.096/kg (≈ €5); packaging fee exempt below 50,000 kg.
8. Ordering timeline
Calendar weeks. Today = 2026-W38 (Thu 17 Sep). Assumption: rev B Gerbers/BOM are ready for R1 by W41, R1 passes by W47, R2 passes by W1 2027. Everything marked ★ is a long-lead buy that doesn't depend on the prototypes.
Holiday blackouts: China Golden Week 1–8 Oct 2026 (JLC posted a Sept–Oct holiday schedule) and Chinese New Year ≈ 6 Feb 2027 (factories and JLC/LCSC slow from ≈ 30 Jan to ≈ 20 Feb). Anything from China for production must ship before ≈ W4 2027 or wait until ≈ W8.
| Week | Order / action | Supplier | ≈ € |
|---|---|---|---|
| W38–39 (now) | KvK + BTW registration; 1NCE business account; diisocyanate course | KvK / 1NCE | – |
| W38–39 ★ | nRF9151: request 525-pc allocation quote (Nordic sales NL, EBV/Avnet, Rutronik, Mouser); place the order or backorder as soon as a price is confirmed (16 wk → ≈ W3 2027) | Nordic distributors | ≈ 7,400 (commit) |
| W38–39 ★ | Buy 24 nRF9151 for R1+R2 (Mouser if stock is real; else JLC global sourcing) | Mouser | ≈ 475 |
| W38–39 ★ | Buy all 161 Würth 760308101214 + 20 TDK WR222230 samples | DigiKey NL | ≈ 790 |
| W38–39 ★ | Pre-order into the JLC parts library: 600 LIS2DW12, 550 BQ51013B, 550 MCP73831, GH headers, LEDs | LCSC/JLC | ≈ 1,650 |
| W38–39 ★ | Buy 550 DRV2605L (if stock confirmed), 550 TPS62849, 550 NSIM-2-C, 550 crystals (unless dropped) – or leave on DigiKey reels until W50 if cash is tight (all in stock) | DigiKey NL | ≈ 1,550 |
| W38–39 | Request quotes + certificates (IEC 62133-2, UN38.3, MSDS) for LP602025 with GH lead; order 20 samples | LiPol Battery, EEMB | ≈ 220 (R2 line) |
| W38–39 | Snaptron F12450: free samples + quote for 1,100 + EU rep | Snaptron | ≈ 30 shipping |
| W38–39 | R1 cells (15) + GH pigtails | Ampul.eu, AliExpress | ≈ 120 |
| W38–39 | Qi pucks for R1: 2 × Samsung EP-P2900BBEGWW, 2 × Belkin WIA011; ask Samsung B2B/ATRIA for a 263-pc quote | retail / distributor | ≈ 130 |
| W39 | Test + workshop + casting equipment (§6) | DigiKey, Eleshop, VEVOR, KERN, Elegoo | ≈ 2,580 |
| W40 | R1 casting materials, 3M 850, PMMA rod, screws, inserts; UV torch (AliExpress, 2 wk) | Syntec, KauPo, FormX, ruthex | ≈ 360 |
| W41 | R1 JLC order (fab + double-side PCBA + X-ray; dome carrier panel); R1 antennas (1004795 + FXP40), LRAs, RF match kit | JLCPCB, DigiKey | ≈ 1,000 |
| W41 | 12 × 1NCE SIMs | 1NCE | 156 |
| W44–46 | R1 boards arrive (3–5 wk incl. global sourcing and DHL) | – | – |
| W45–47 | R1 tests that gate purchases: TDK vs Würth coil, antenna choice, puck BPP charging, insert/screw closure, LED window, cast fit | – | – |
| W47 | R2 JLC order (production-intent); R2 LRAs/antenna/coils; 12 SIMs; 5 × chosen puck; Smooth-Cast 300; prototype packaging | JLCPCB, DigiKey, 1NCE, FormX, Rajapack | ≈ 1,300 |
| W48 | Decide coil (TDK → order 525 at DigiKey, 10 wk lead but 8,216 in stock) and antenna (order 550) | DigiKey | ≈ 900–1,100 |
| W48 | Order 1,100 F12450 domes | Snaptron | ≈ 370 |
| W49 | Packaging quotes/samples (Packhelp sample box, insert DXF) | Packhelp | – |
| W50 ★ | Production cells: 625 (525 + 100 spares) with GH lead, after certificate review – ships before CNY; DG air | LiPol Battery | ≈ 2,550 |
| W50–51 | R2 boards arrive; R2 build; R2 units go to the compliance lab | – | – |
| W51 | 263 Qi pucks (B2B) | Samsung distributor | ≈ 6,300 |
| W1–2 2027 | R2 sign-off → JLC production order (525 boards; nRF consigned or global-sourced); production casting materials (PMC-770 ×2, Mold Star 30 ×2, Smooth-Cast ×2, pigments, Siraya Blu 12 kg) | JLCPCB, FormX, KauPo | ≈ 3,100 |
| W2 | Packhelp mailers + inserts + manual print | Packhelp, Drukwerkdeal | ≈ 1,020 |
| W3–4 | Production boards ship from JLC (must leave before CNY, else ≈ W8–9) | JLCPCB | – |
| W5 | 1NCE: 525 SIMs (late, because the 10-year clock may start at order) | 1NCE | 6,825 |
| W5–10 | Cast skins and cradle shells, assemble, test, box (≈ 525 units over 5–6 weeks) | workshop | – |
| W13–16 | Compliance certificates expected (10–16 wk from R2 samples) → start selling | – | – |
| ≈ 2029 | Spare cells batch 2 (100) | same cell model | ≈ 450 |
9. Totals per phase
EUR. Electronics, PCB, SIM, cell and puck figures are ex VAT (reclaimable); casting, equipment and packaging figures are mostly incl VAT as the shops list them. Contingency: 10 % on prototypes, 5 % on production.
| Phase | Main lines | Subtotal | With contingency |
|---|---|---|---|
| Prototype R1 (10 lemons, 12 boards) | electronics parts €720 (12 × €44 + antenna variants + RF kit + TDK samples), JLC fab/PCBA/domes-carrier €280, SIMs €156, cells €120, puck test set €130, casting €330, closure €25, dome sample shipping €30 | €1,791 | ≈ €1,970 |
| Prototype R2 (10 lemons, production-intent) | electronics €530, JLC €280, SIMs €156, cert-grade cells €220, 5 pucks €175, casting €400, closure €25, prototype packaging €85 | €1,871 | ≈ €2,060 |
| Production (525 lemons, 263 cradles) | electronics parts €15,645 (Würth coil) + sourcing/consignment fees €200, JLC €780, dome freight €60, 1NCE SIMs €6,825, cells 625 + freight + duty €2,555, Qi pucks 263 × €24 = €6,310, closure €200, casting €2,350, packaging €1,020, EPR fees €25 | €35,970 | ≈ €37,800 |
| Equipment (one-off) | test/programming €450, electronics workshop €890, casting workshop €1,240 | €2,580 | ≈ €2,580 |
| Total sourcing | ≈ €44,400 |
Lean production variant ≈ €31,400 (incl. 5 %): TDK coil (−€1,630), a WPC-listed OEM puck at ≈ €9 (−€3,950), PT Flex 70 + FormSil 25 (−€500).
Budget warning: COMPLIANCE.md expects ≈ €46k (low €19k) for testing. Sourcing ≈ €44k + compliance ≈ €46k ≈ €90k against a €50k goal. Even lean sourcing + low-case compliance is ≈ €55k. Per unit, production is ≈ €72 per lemon incl. its share of cradle and box (€37.8k / 525), of which the nRF9151 (€14), SIM (€13) and puck (€12 per lemon) are 54 %. PLAN.md needs to cut scope (e.g. 250 lemons first, pre-orders) or raise the budget.
Not included: outbound postage (≈ €1,850, charged to buyers), spare-cell batch 2 (≈ €450 in 2029), compliance lab fees, KvK/1NCE admin, labour, workshop rent.
10. Supply risks and mitigations
| Risk | Impact | Mitigation |
|---|---|---|
| nRF9151 allocation – DigiKey 0 stock (100 due 20 Nov), LCSC 0, 16-wk factory lead | Blocks production boards | Request a 525-pc allocation this week (Nordic NL, EBV, Rutronik, Mouser); buy the 24 prototype SiPs now; JLC global sourcing as a second channel. |
| Würth RX coil – only 161 at DigiKey, 26 wk | Can't build 525 | Buy all 161 now; qualify TDK WR222230-26M8-G (8,216 in stock) in R1 with a dual 19/22 mm keep-out and a tunable cap footprint. |
| BQ51013B 26 wk / LIS2DW12 24 wk / crystal 20 wk / DFE inductor 21 wk factory leads | Stock can vanish before W2 2027 | Pre-order into the JLC parts library (or buy the DigiKey reels) now. |
| Chinese New Year (≈ 6 Feb 2027) and Golden Week (1–8 Oct 2026) | 2–3 week stop at JLC, LCSC, cell factory | Cells ordered W50; JLC production must ship by ≈ W4; R1 order after 8 Oct. |
| Cells without model-specific IEC 62133-2 / UN38.3 | Blocks compliance and shipping | Refuse cells without reports; two suppliers quoted; R2 uses the production cell. DG courier for loose cells. |
| Qi2 puck with a non-magnetic BPP receiver | Poor or no charging | Test Samsung + Belkin in R1; generic WPC-listed puck as third option. |
| 1NCE 10-year clock may start at order | Lose months of SIM life | Order production SIMs ≈ W5 2027, confirm with 1NCE. |
| Antenna – nothing fits 30×6 mm for band 20 | Weak coverage, possible NB issue with EN 301 908-13 | Prototype 1004795 vs FXP40 in R1; accept a 36–43 mm antenna in the mechanical design. |
| Low stock at FormX (PMC-770: 1, Mold Star 30: 3) | Casting delay | Split between FormX and KauPo; PT Flex 70 (Syntec) and FormSil 25 as alternates. |
| Platinum silicone vs SLA masters | Mold won't cure | Post-cure + seal masters, patch test; tin-cure FormSil 25 fallback. |
| B2B import paperwork since 1 Jul 2026 (formal declaration for every B2B parcel) | €15+ per parcel, delays | Consolidate China orders (JLC + LCSC in one shipment); use DHL account rates. |
11. Open questions
- ~~External 32.768 kHz crystal~~ resolved: removed in rev B (ELECTRONICS_REVB.md). Still confirm against the nRF9151 Product Specification when the R1 boards arrive.
- nRF9151 525-pc price and delivery from Nordic's distributors – the single biggest schedule risk.
- Samsung EP-P2900 B2B price at 263 and whether it charges a BQ51013B BPP receiver reliably; if not, which WPC-listed OEM puck.
- LiPol / EEMB: model-specific IEC 62133-2 report, GH connector fee, real price at 625.
- Snaptron F12450 price and MOQ at 1,100; EU distributor.
- Retail box size: does a standard Packhelp size fit the leaf + 2 lemons (saves the 1,500 MOQ)?
- Closure: screws + heat-set inserts in SLA resin, or twist-lock + O-ring (needs core diameter from the mechanical stream).
- Budget: sourcing ≈ €44k plus compliance ≈ €46k exceeds €50k – scope decision needed in PLAN.md.
BOM.md not edited. Differences for the electronics stream to pick up: TPS62849DLCR is VSON-HR (not WSON); battery connector recommended as JST GH (BM02B-GHS-TBT) instead of bare leads/SH; crystal requirement unresolved; rev B adds LIS2DW12TR + APHHS1005SYCK; antenna 1004795 or FXP40 instead of a custom 30×6 mm FPC.