Sambuca — Shop Packet (Print Edition)

Build target: SAM-13-ROOT — 650 mm boat-shaped arched harp, 13 strings, G-major. Status: private review (pending three release gates). Packet version: instrument-maker-v4, generated 2026-05-16.

This is the printable shop packet. Take it to the bench. Cross-reference back to the live files in the repo when in doubt.

File map (one-page reference)

File	Purpose	Take to bench?
`design.md`	Design intent, fingerprint, soundhole strategy, cultural provenance	reference only
`reverse-engineering.md`	Source-material analysis	reference only
`family-spec.csv`	5-variant table	reference only
`risks.md`	Red-team risk register with verification tests	check before each stage
`bom.csv`	Make/buy materials and hardware	yes — ordering
`sourcing.csv`	Candidate suppliers, planning prices	yes — ordering
`cut-list.csv`	Rough and final dimensions for every cut	yes — bench
`validation.csv`	Dimensional, tension, acoustic, joint, safety, cultural checks	yes — bench
`assembly-manual.md`	12-stage build sequence with hold points	yes — bench
`supplier-rfq.md`	RFQ drafts to send out	yes — ordering
`drawing-brief.md`	Drawing-package spec	reference only
`cad/SAM-000_master-equations.txt`	Global equations (source of truth)	reference only
`cnc/cnc-plan.md`	Pre-CAM operation plan per part	yes — bench
`wolfram/sambuca-acoustics-starter.wl`	Acoustic study notebook	reference only
`photo-shotlist.md`	Capture list across the build	each stage
`harness/README.md`	SAM-19 + SAM-25 harness design	only for those variants
`capstone-deck.pptx`	Capstone presentation	not in shop
`site/index.html`	Build-log site (private until release)	not in shop

Design intent (one paragraph)

Modern parametric family-scalable boat-shaped arched harp that preserves the Sumerian visual fingerprint (gold-flared cap, 13 bulb pegs with cord wraps, J-curve neck, multi-strip lapis band, brass collar, bow-end inlay panel, two stern stub feet) while delivering modern playability (geared tuners hidden behind decorative caps, calibrated fluorocarbon + wound-nylon string set at 65–80 kgf, keel-port soundhole projecting forward toward the listener, CNC-machined hull/neck/inlay, kanawa-tsugi stand). Build target SAM-13-ROOT; four siblings (SAM-19-MID, SAM-25-CONCERT, SAM-13-AE, SAM-13-MULE) derive from the same MasterLayout via body_length_mm and string_count.

Cultural provenance — for the public-release language

Inspired by the Sumerian boat-shaped arched harp from BM 121198 (Royal Cemetery at Ur, c. 2600 BC, ~4500 years old, public domain). Not a reproduction, not a recreation of any specific surviving artifact, not a claim of cultural authority over any modern living tradition. The Hellenistic Greek sambykē (σαμβύκη) etymological link is historically contested; the build uses the term while acknowledging the uncertainty.

Family-spec summary

ID	Body length	Strings	Tuning	Total tension	Harness
SAM-13-ROOT	650 mm	13	G3 → E5	65–80 kgf	none
SAM-19-MID	850 mm	19	D3 → G5	~100 kgf est.	low-back belt
SAM-25-CONCERT	1050 mm	25	A2 → A5	~120 kgf est.	sax harness
SAM-13-AE	650 mm	13	G3 → E5	65–80 kgf	none + piezo
SAM-13-MULE	650 mm	13	G3 → E5 (reduced T)	40–50 kgf	none

Wood pairing (locked)

Component	Species
Hull (and stand)	Walnut — FAS quartersawn 8/4
Soundboard	Western red cedar — quartersawn AAA 3 mm (Wolfram-sweep 2.5–4.0)
Neck	Sapele — three 12 mm laminates around a curved form
String-holder strip	Walnut or hard maple
Bracing	Cedar (matches soundboard movement)

BOM summary (SAM-13-ROOT)

See full bom.csv for all 44 lines and per-variant deltas. Headline cost: planning estimate $530–1300 USD for SAM-13-ROOT, prices not live-verified.

Highest-risk supply items:

BOM-018 PVD-gold-tone brass bulb caps (13) — custom part, longest lead. Parallel two-shop search.
BOM-017 Geared guitar tuners (13) — mock-fit one sample before bulk order to verify neck_depth_mm clearance.
BOM-007 Bow-end inlay panel (mother-of-pearl or composite) — three-candidate sample compare before commit.

Sourcing summary

Spec-first table in sourcing.csv. Three candidate suppliers per line. No live prices verified — confirm before ordering.

Order in this sequence to fit the 6–10 week build:

Week 1: PVD bulb caps (3–5 week lead) + walnut hull stock (2–4 weeks).
Week 2: sapele neck stock, cedar soundboard, tuners (mock-fit first).
Week 3: brass collar tube, eyebolts, string sets (after Wolfram sweep).
Week 4: inlay materials.

Cut-list (build-target subset)

Full table in cut-list.csv. Highlights:

Cut ID	Part	Final dims	Material	Notes
CUT-001a or CUT-001b	Hull	650 × 150 × 150 mm, wall 6 mm	Walnut	A: CNC-from-block. B: stave-laminated. Pick one.
CUT-009 + CUT-011	Neck blank	~810 mm arc, 38 × 38–50 mm cross-section	Sapele 3-laminate	Glue → cure 48 hr → CNC sweep
CUT-005	Soundboard	650 × 150 × 3 mm	Cedar QSAAA	Final after sanding
CUT-007	String-holder strip	120 × 10 × 4 mm	Walnut or maple	Glued after voicing on MULE
CUT-018	Keel port	80 × 50 mm oval, 15° forward tilt	(cut from hull)	Stage 6
CUT-014	Brass collar	60 mm tall, ~1 mm wall	Brass tube	Aged or polished per R-F-02
CUT-023	Multi-strip lapis inlay pocket	5 × 1.5 mm strips + 4 × 0.8 mm spacers	(route in soundboard)	0.8 mm end mill
CUT-026	Bow-end inlay panel pocket	100 × 60 × 1.5 mm	(route in soundboard)	Per `bow_panel_x_from_stern_mm`

Drawing brief callout

Minimum drawings required for the Fall 2026 capstone (see drawing-brief.md for the full 22-sheet list):

Sheet 01 — Overview front
Sheet 02 — Overview side (shows bow lift + keel port)
Sheet 10 — Soundboard inlay program
Sheet 18 — Family overview

Source of truth: cad/SAM-000_master-equations.txt. SVGs are generated from SolidWorks once the rebuild per cad/SW-MIGRATION-CHECKLIST.md clears.

Assembly stages (one-line summary each)

#	Stage	Hold?	Critical risk
0	Pre-build (sourcing, fixtures, tuner mock-fit)	yes — R-X-04 mock-fit before cutting stock	—
1	Hull (Path A or Path B)	yes — wall thickness verified	R-S-04
2	Neck blank (laminate + CNC sweep)	yes — scarf cut clean	R-S-01
3	Soundboard (3 mm cedar, fan brace, inlay pockets cut not filled)	yes	R-F-01
4	Hull seam scarf + brass collar	yes — V-J-01 at 24h and 48h	R-S-01
5	Soundboard installation + inlay filling	yes	—
6	Keel port cut	yes — V-S-03 decision	R-S-03
7	Stand (CNC-curve + kanawa-tsugi)	parallel	—
8	Tuners + cord wraps + bulb caps	yes — fingerprint complete	—
9	String-holder strip + prototype voicing on MULE	yes — V-A-05 voicing decision	R-A-01
10	MULE 30-day hold + ROOT gradual stringing	GATE — V-S-01 + V-T-02	R-S-01 + R-S-04
11	Final voicing + acoustic measurement	yes — V-A-01	R-A-01
12	Documentation + brand integration	yes — V-C-01 + V-B-01	R-C-01

Full manual at assembly-manual.md. Read it before starting.

Validation / tuning sheet (printable)

Full table in validation.csv. Bench-side highlights:

Dimensional checks (V-D-01 through V-D-14)

[ ] Body length 650 ± 2 mm
[ ] Body width 150 ± 2 mm
[ ] Body depth 140–170 mm
[ ] Instrument height 810 ± 5 mm
[ ] Hull-wall thickness 6 ± 0.5 mm at midship, bow, stern
[ ] Neck arc 710 ± 5 mm
[ ] Brass collar 60 ± 1 mm
[ ] String-holder strip 120 × 10 × 4 mm
[ ] Tie-through holes 13, ±0.3 mm spacing, Φ1.5 mm
[ ] Multi-strip lapis band 11–13 mm total width
[ ] Bow-end inlay panel 100 × 60 × 1.5 mm pocket
[ ] Keel port 80 × 50 mm, 12–18° forward tilt

Structural checks (V-S-01 through V-S-05)

[ ] SAM-13-MULE 30-day neck-deflection ≤ 2 mm at gold cap
[ ] Brass collar gap monitor ≤ 0.3 mm over a season
[ ] Soundboard pull-test holds 2× service load
[ ] Stern eyebolt holds 30 kgf for 60 s (SAM-19/25/AE only)
[ ] Keel-port keel deflection ≤ 1.5× unported case

Tension checks (V-T-01 through V-T-04)

[ ] MULE total 40–50 kgf
[ ] ROOT total 65–80 kgf (calibrated)
[ ] ROOT 30-day tension drift < 10%

Acoustic checks (V-A-01 through V-A-05)

[ ] SPL at 1 m within ±6 dB of Wolfram prediction
[ ] Coupled cavity-plate pair signature (two peaks split 30–80 Hz)
[ ] Tuning drift < ±10 cents per string at 24 hr
[ ] Keel-port Helmholtz 128–158 Hz
[ ] String-holder strip position locked after voicing

Cultural + brand gates (V-C-01 through V-B-02)

[ ] Cultural-advisor sign-off on provenance language
[ ] Every BM 121198 and cylinder-seal image credited
[ ] Heifer Zephyr placement option locked

Supplier-RFQ summary

Send these RFQs in week 1. Full drafts in supplier-rfq.md.

RFQ	To	Items
RFQ-1	Wood supplier	Walnut hull stock, walnut 12/4 base, cedar soundboard (2.5 + 3.0 mm), sapele neck stock, cherry brace stock, holly/maple spacer veneer
RFQ-2	Brass/stainless supplier	Brass tube for collar (×2 for spare), stainless dowel pins, stainless eyebolts, brass rod for cap turning
RFQ-3	String supplier	Set A (G-major calibrated, 13 strings), Set B (A-major drop-in), Set C (MULE reduced tension)
RFQ-4	Tuner supplier + PVD finisher	13 compact-housing geared tuners + 13 PVD-gold-tone bulb caps (custom-machined or sourced)
RFQ-5	Inlay supplier	Dyed-blue veneer (5 strips × 3 m), holly/maple spacer, MOP/shell composite panel (3 samples for compare), brand inlay stock
RFQ-6	Harness supplier	Low-back belt + locking hook (SAM-19), sax harness + locking hook (SAM-25)
RFQ-7	Electronics supplier	Under-strip piezo + 1/4" jack + wiring (SAM-13-AE only)

Visual BOM brief

One-page visual BOM lives in visual-bom-brief.md plus the rendered visual (placeholder until the photo set is captured). Print last, when the SAM-13-ROOT is finished and photographed.

Appendix — risks worth a second look before each stage

R-S-01 Neck cantilever failure — the single highest risk. Hold the MULE for the full 30 days before stringing the ROOT.
R-S-04 Soundboard collapse — pull-test the string-holder-strip glue line on scrap cedar before mounting the production strip.
R-S-05 Eyebolt pull-through — only matters for SAM-19/25/AE, but it's a safety gate when it does.
R-A-01 Quiet voice on SAM-13-ROOT — the small 3.8 L cavity is the chronic concern. Wolfram-sweep before committing soundboard thickness; iterate on MULE.
R-C-01 Cultural-advisor review — public-release gate. Submit the provenance language early; don't wait until Stage 12.
R-X-03 PVD bulb caps — longest-lead supply item. Order in week 1.

Public-release gate checklist (final page)

[ ] V-S-01 SAM-13-MULE neck-deflection 30-day hold passed
[ ] V-T-02 SAM-13-ROOT calibrated-tension target hit (65–80 kgf)
[ ] V-C-01 Cultural-provenance advisor review signed off
[ ] V-B-01 Heifer Zephyr placement option locked (A soundboard or B stand)
[ ] R-S-05 SAM-25 eyebolt pull-test passed (if SAM-25 in release scope)
[ ] All validation.csv cultural-category rows closed (V-C-01, V-C-02, V-C-03)
[ ] site/index.html private-review banner removed
[ ] README.md updated to public-release language
[ ] License files in place (CERN-OHL-W-2.0 for design, CC-BY-4.0 for content)

Tony Koop · Heifer Zephyr · Sambuca SAM-13-ROOT · Fall 2026 capstone · private review