Vessel Flutes Build Packet Print Packet

Generated: 2026-05-09

Packet folder: `/tmp/vessel-flutes-codex-bob-r3-build-packet`

File Map

design.md

Project intent, catalog metadata, assumptions, and validation plan.

Design

Design Intent

Create an L2 root-mode build packet for vessel flutes whose pitch behavior is

set by Helmholtz resonance. The first prototype is a 130 cc ceramic ocarina lab

body with a conservative voicing and undersize finger holes. The purpose is to

validate cavity volume, voicing response, cumulative hole area, and shrinkage

before committing to a polished slip-cast family.

This packet supports issue #1 as a reviewable packet candidate. It does not

claim L3/build-ready status until measured cavity volume, shrinkage, and tuner

data are added to `validation.csv`.

Governing Model

Helmholtz resonance:

f = c / (2*pi) * sqrt(A / (V * L_eff))
L_eff = wall_thickness + end_correction
end_correction ~= 0.6 * sqrt(A/pi)

Variables:

• `f`: target frequency in Hz.
• `c`: speed of sound, about 34300 cm/s at 20 C.
• `A`: effective open area in square centimeters.
• `V`: cavity volume in cubic centimeters.
• `L_eff`: effective neck length in centimeters.

For finger-hole notes, `A` is cumulative effective area, not tube length. Hole

interaction and hand coverage require empirical correction.

Starter Bodies

Finger-Hole Area Plan

1. Calculate required cumulative area for each target note.

2. Convert each incremental area into an undersize drill diameter.

3. Drill small, measure, enlarge, and record the final diameter.

4. Update the hole-area curve before copying the body into a mold.

Starter scale for VF-130-A4 is a simple major pentatonic: `A4, B4, C#5, E5,

F#5, A5`. A chromatic fingering chart is out of scope for this L2 pass.

Ceramic And Prototype Path

• Quick prototype: hand-shaped clay or sealed printed/plaster mockup with

water-fill volume measurement.

• Ceramic path: slab or pinch body first; slip-cast mold only after shrinkage

and voicing are measured.

• Mold workflow: preserve the existing `mold-workflow.md` notes and add fired

shrinkage rows after test tiles.

SolidWorks/OpenSCAD Handoff

The CAD handoff should expose volume, voicing area, wall thickness, hole

diameters, and mold split line as named inputs. A pretty exterior is secondary

until the Helmholtz measurements agree with the design sheet.

L2 To L3 Gates

• Actual cavity volume measured within +/-5 cc.
• First sound is stable at low and medium breath pressure.
• Fundamental is within +/-20 cents before tuning holes.
• Tuned pentatonic notes are within +/-10 cents or documented as correction

data.

• Fired shrinkage is measured before a slip-cast production mold is claimed.

bom.csv

Starter bill of materials with part categories, quantities, drawing refs, and notes.

sourcing.csv

Supplier/search tracker with specs, price/date fields, lead time, substitutes, and risks.

cut-list.csv

Rough/final stock sizes, material, grain/orientation, operations, yield, and offcuts.

drawing-brief.md

Manufacturing drawing and technical product sketch brief.

Drawing Brief

Required Sheets

1. VF-130-A4 body overview with approximate cavity, voicing, and hand position.

2. Section view showing cavity volume, wall thickness, windway, and labium.

3. Finger-hole area chart with undersize drill diameters and final measured

diameters.

4. Mold split-line concept after shrinkage validation.

Datum Scheme

• A: voicing centerline.
• B: mouthpiece/windway reference face.
• C: body midplane for hole layout and mold split discussion.

Tolerance Notes

Volume, voicing, and hole area are validation variables. Drawings should label

starter dimensions as first-pass values until the measured body is logged.

assembly-manual.md

Shop-facing sequence, tools, fixtures, safety, tuning, finishing, and maintenance notes.

Assembly Manual

Scope

This manual covers the VF-130-A4 lab body. A slip-cast version should wait

until the hand-built or sealed proof body validates volume, voicing, and hole

area.

Steps

1. Weigh clay and form a simple closed cavity with an inspection/fill opening.

2. Shape the body around the 130 cc target volume, leaving extra wall thickness

near the voicing.

3. Cut a conservative windway/window and smooth the labium edge.

4. Measure wet cavity volume by water fill and record in `validation.csv`.

5. Dry slowly; measure shrinkage against test tiles.

6. Seal the proof body if needed for first acoustic tests.

7. Establish first sound before drilling tone holes.

8. Drill tone holes undersize according to the area plan.

9. Tune by gradual enlargement, recording final diameters and cents error.

10. Fire or finish only after the acoustic target is stable.

11. Re-measure cavity volume after firing or sealing.

12. Update `mold-workflow.md` with the measured shrinkage before any slip-cast

mold is cut.

Stop Conditions

• Stop if the cavity leaks; pitch observations are meaningless until sealed.
• Stop if volume differs by more than 10 cc; update design before drilling.
• Stop if first sound requires high breath pressure only; adjust voicing before

tuning holes.

validation.csv

Target/measured values, tolerance, environment, result, and tuning/build action log.

supplier-rfq.md

Supplier email/request-for-quote starter.

Supplier RFQ

Request

Please quote the following public-safe, non-proprietary instrument-build

materials or fabrication services.

Items

• Item: TBD
• Quantity: TBD
• Material/spec: TBD
• Tolerance: TBD
• Finish: TBD
• Lead time target: TBD

visual-bom-brief.md

Art direction for an image-forward visual BOM.

Visual BOM Brief

Create a one-page visual BOM after the first prototype is shaped. Required

image panels:

• Clay body or proof cavity before closure.
• Water-fill measurement setup.
• Voicing window and labium close-up.
• Drill/reamer set used for tuning holes.
• Test tiles used for shrinkage measurement.
• Final tuned prototype, front and back.

Each panel should link to the validation row it supports.

wolfram-starter.wl

Wolfram starter for physics, optimization, visualization, and validation.

(* Vessel flute Helmholtz starter: cavity volume and hole area. *)

ClearAll["Global`*"];

cCmPerSec = 34300;
a4 = 440;
volumeCc = 130;
wallCm = 0.40;

areaCircleCm2[dmm_] := Pi*(dmm/20)^2;
endCorrectionCm[area_] := 0.6*Sqrt[area/Pi];
helmholtzHz[area_, volume_, neck_] := (cCmPerSec/(2*Pi))*Sqrt[area/(volume*neck)];
areaForHz[f_, volume_, neck_] := volume*neck*(2*Pi*f/cCmPerSec)^2;
centsError[measured_, target_] := 1200*Log[2, measured/target];

baseArea = 0.45;
baseNeck = wallCm + endCorrectionCm[baseArea];
baseHz = helmholtzHz[baseArea, volumeCc, baseNeck];

scale = {
  {"A4", 440.00},
  {"B4", 493.88},
  {"C#5", 554.37},
  {"E5", 659.25},
  {"F#5", 739.99},
  {"A5", 880.00}
};

areaTable = Table[
  <|
    "Note" -> note,
    "TargetHz" -> hz,
    "CumulativeAreaCm2" -> areaForHz[hz, volumeCc, baseNeck]
  |>,
  { {note, hz}, scale}
];

Dataset[areaTable]

(* Validation reminder: effective hole area must be measured on a prototype;
   this is not an open-pipe tone-hole model. *)

CHECKLIST.md

Project artifact.

Public-Ready Checklist

Readiness Level

• [ ] L0 Concept: target sound, family, and rough build method are documented.
• [ ] L1 Design: governing equations, assumptions, dimensions, BOM, and sourcing candidates are present.
• [ ] L2 Shop Packet: build sequence, drawings/briefs, cut list, validation checklist, hazards, and artifact paths are complete enough for careful builder review.
• [ ] L3 Validated Packet: validator passes, generated/rendered artifacts open, units are consistent, and sourceability/tolerance claims are checked.
• [ ] L4 Empirical Packet: measured build data, tuning deviations, correction loop, and catalog feedback are included.

Only L3 or L4 work should be described as build-ready.

Packet Completeness

• [ ] Replace `Vessel Flutes`, `L2 root-mode build packet for Helmholtz vessel flutes: ocarina, xun, gemshorn, and ceramic cavity prototypes.`, and other placeholders.
• [ ] Add cultural attribution and sources of inspiration.
• [ ] Replace placeholder photos with owned photos, renders, or honest public-safe placeholders.
• [ ] Fill `design.md` with instrument-specific governing equations and assumptions.
• [ ] Fill BOM, sourcing, cut list, validation, and family spec rows with non-placeholder values.
• [ ] Add OpenSCAD/SolidWorks/Wolfram handoff notes without pretending final CAD exists.
• [ ] Add drawings and a CNC/setup plan where applicable.
• [ ] Fill `resources.md` with public-safe provenance, education, maker, and license notes.
• [ ] Fill `jig-decision.md` for any make/order/buy/borrow fixture decisions.
• [ ] Run `instrument-maker-v4/scripts/validate_packet.py . --mode root --json`.
• [ ] Confirm no local absolute paths, private repo links, or frozen supplier-price claims.

Review Evidence

• [ ] PR body includes changed behavior/artifact, physics/manufacturing assumptions, validation run, known gaps, reviewer focus, and do-not-merge-until bar.
• [ ] Physics gate passed: model, assumptions, units, tuning targets, and sensitivity ranges are reviewable.
• [ ] Manufacturing gate passed: toolchain, materials, tolerances, cut lists/jigs/CAD, and assembly order are plausible.
• [ ] Safety gate passed: dust, finishes, adhesives, sharp tools, tension, heat/pressure/electrical risks, and workshop constraints are addressed.
• [ ] Artifact gate passed: BOM, sourcing, cut list, validation, risks, drawings/CAD briefs, and rendered/generated artifacts are present or gaps are named.
• [ ] Empirical gate passed: measurement plan, pass/fail criteria, tuning correction path, and catalog feedback destination are stated.

README.md

Project artifact.

Vessel Flutes

> L2 root-mode build packet for Helmholtz vessel flutes: ocarina, xun,

> gemshorn-inspired ceramic studies, and quick cavity-volume prototypes.


What This Is

This repository documents a vessel-flute build packet where pitch is governed

primarily by cavity volume, voicing aperture area, and effective neck length,

not by open-pipe tube length. The first build target is a small ceramic ocarina

lab body because it can validate volume measurement, voicing response, and

finger-hole area formulas before more ornate forms are attempted.

The packet is **L2, not L3**. It is a reviewable root-mode packet with formulas,

shop sequence, and validation gates, but it is not build-ready until a fired or

prototype body has measured volume, shrinkage, and tuning data.

Refs #1.

Design Overview

Why Hole Area Matters

For vessel flutes, a tone hole does not "shorten a tube." It increases the

effective open area of the resonator. The practical tuning loop is:

1. measure dry/fired cavity volume;

2. calculate target cumulative open area for each note;

3. drill holes undersize;

4. enlarge holes gradually while measuring pitch;

5. update the hole-area curve with real data.

This packet keeps that distinction explicit so pipe-flute shortcuts do not

creep into the vessel-flute workflow.

Packet Map

Build Order

1. Make a quick clay or sealed prototype body with measurable volume.

2. Cut a conservative voicing window and establish first sound.

3. Measure cavity volume by water fill before and after drying/firing when

applicable.

4. Drill tone holes undersize and tune by cumulative open area.

5. Record fired shrinkage and update the mold/slip-cast plan.

Status

License

[CC BY 4.0](LICENSE) - engineering documentation only.

concept-matrix.csv

Project artifact.

experiments.csv

Project artifact.

family-spec.csv

Project artifact.

jig-decision.md

Project artifact.

Jig Decision

mold-workflow.md

Project artifact.

Vessel Flute Mold Workflow

CAD First Principles

• Model the **inside air volume** intentionally, not just the exterior sculpture.
• Keep a named chamber-volume parameter or a repeatable CAD volume report.
• Avoid true undercuts unless using a multi-part mold.
• Add shrinkage compensation as a configurable scale factor.
• Design the split line before falling in love with the outside form.
• Put fipple and hole features in locations that can be cleaned, measured, and tuned.

Master Print

1. Print at high enough resolution that fipple and port areas are not stair-stepped.

2. Sand and seal the master completely.

3. Measure master dimensions and compare with CAD.

4. Mark split line, datums, and build ID.

Plaster Mold

1. Choose 2-piece mold for simple pods and 3-piece mold for forms with more dramatic shoulders.

2. Use registration keys that release cleanly and do not create stress risers.

3. Keep plaster thick enough for strength but not so massive that drying takes forever.

4. Dry the mold fully before judging casting performance.

Casting Controls

• Record slip batch.
• Record pour time, drain time, room temperature, and humidity if available.
• Measure wall thickness from a sacrificial rim or test coupon.
• Use the same drain orientation for each comparison build.

Fipple Strategy Options

Mold-Release Design Rules

• Organic outside forms are fine if every mold segment has a pull direction.
• Texture should be shallow until the release behavior is proven.
• Avoid thin raised details near the mouthpiece, hole edges, and split line.
• Keep the first prototype simpler than the final sculpture; prove tone first, then make it wild.

photo-shotlist.md

Project artifact.

Photo Shotlist

• Hero image of completed instrument or honest concept placeholder.
• Scale reference with ruler/calipers.
• Material blank before cutting.
• Key operations and jigs.
• Detail shots of acoustic features.
• Final validation setup.

resources.md

Project artifact.

Resources

Engineering References To Gather Before L3

• Measured ocarina or vessel-flute cavity volumes and voicing dimensions.
• Ceramic body shrinkage data for the exact clay and firing schedule.
• Finger-hole area calculation references and measured correction curves.
• Photos or drawings of voicing geometry with reuse permission.

Existing Local Context

• `docs/ceramic-vessel-lab/` contains previous ceramic vessel-lab notes that

should be preserved as design history.

• `concept-matrix.csv` and `experiments.csv` remain useful intake artifacts.
• `mold-workflow.md` is the right place to promote measured shrinkage into the

slip-casting path.

Related Repos

• `tonykoop/ocarina` for single-instrument Helmholtz packet style.
• `tonykoop/gemshorn` for slip-cast vessel-flute family handling.
• `tonykoop/udu` for ceramic cavity-volume measurement discipline.
• `tonykoop/instrument-maker` for formulas and validation scripts.

review-evidence.md

Project artifact.

Review Evidence

Refs #1.

Round 3 Scope

• Added an L2 root-mode build packet scaffold and hand-tuned it for

vessel-flute specifics: Helmholtz cavity volume, effective hole area,

voicing response, ceramic shrinkage, mold timing, and ocarina-style

prototype validation.

• Existing ceramic vessel-lab notes were preserved under `docs/`.
• This packet does not claim L3/build-ready status.

Gates Before Close

• Measure wet/dry/fired cavity volume and shrinkage.
• Record first-sound behavior, cumulative hole areas, tuned cents error, and

leak checks in `validation.csv`.

• Promote slip-cast mold work only after the lab body validates.

risks.md

Project artifact.

Risks