# Wooden Hang

![Wooden Hang concept](images/hero-concept.svg)

Handpan-inspired wooden idiophone / resonant-vessel hybrid research packet

# Project Intent

Wooden Hang explores whether wood can support a lap-played circular note layout with enough pitch clarity, sustain, and ergonomic coherence to justify a new instrument family. This project does **not** claim that wood behaves like hammered steel or that a PANArt Hang can be reproduced by changing material alone.

The first design commitment is not "build the prettiest shell." It is "learn the fastest honest acoustic truth." That is why the packet leads with coupons, a single-field rig, and a three-note sector before a full 9-note layout.

# Why This Is Interesting

- It combines wooden idiophone behavior with resonant-vessel coupling.
- It keeps the handpan-like playing geometry while allowing a more repairable prototype ladder.
- It could reveal a new family identity even if the final instrument sounds less like steel and more like a wooden tonal vessel.

# Target Family

- Working name: Wooden Hang
- Primary concept size: 18 in class body, 4.75 in overall height
- First full target: G minor 9-note layout
- Primary prototype path: replaceable top-plate hybrid over resonant bowl

# Governing Model

![Layout drawing](drawings/wooden-hang-layout.svg)

The instrument is modeled as a coupled system:

- local note zones behave like small plates or tongue-like hybrid regions
- the bowl and port behave like a cavity resonance system
- the exact tuning outcome is empirical because grain direction, glue lines, and slot geometry matter

First-order trend:

```text
f_field ~= (kappa / (2*pi)) * (h_local / a_eff^2) * sqrt(E_eff / (rho_eff * (1 - nu^2)))
```

# Branch Comparison

Three construction paths were evaluated:

1. top-plate hybrid over bowl
2. split-shell CNC carved body in four operations
3. segmented or stave shell with tuned top

The hybrid path wins for first build because it preserves the circular layout while keeping the top replaceable and the tuning variables accessible.

# Prototype Ladder

| ID | Goal | Exit gate |
| --- | --- | --- |
| WHG-P0 | Coupon studies | Repeatable measurable note trend |
| WHG-P1 | Single-field cavity rig | One field plus one cavity coupling path |
| WHG-P2 | Three-note sector | Cross-talk stays manageable |
| WHG-P3 | Five-note subset | First playable subset |
| WHG-P4 | Full 9-note concept | Data-backed go/no-go on full family |

# Note Layout

- Ding: G3
- Outer notes: Bb3, C4, D4, F4, G4, Bb4, C5, D5
- Note sizes are marked as assumptions or derived estimates until measured
- A five-note or three-note layout is allowed to become the real first instrument if the geometry demands it

# Manufacturing Plan

![Section drawing](drawings/wooden-hang-section.svg)

- start with stable top stock and small coupons
- build a removable-top test rig
- route or build a bowl with interchangeable port sizes
- escalate to sector and subset builds before the full shell
- reserve the four-operation split-shell CNC path as a documented alternate

# CAD And CNC

- `cad/wooden_hang_master.scad` holds the concept geometry and named inputs
- SolidWorks integration files define global variables and design-table fields
- CNC planning includes top routing, cavity routing, datum control, and alternate body strategies

# Validation Plan

Validation is designed to prove or disprove the concept, not merely describe it.

Measure:

- target vs measured pitch
- cents error
- decay time
- cross-talk
- body or port resonance
- moisture content
- structural failures and buzz sources

# Risks

- note fields may not sustain enough
- adjacent notes may couple too strongly
- the full 9-note map may be too dense for honest wooden field sizes
- finish, hardware, and humidity may shift pitch more than expected

Every risk in `risks.md` has a concrete verification test attached.

# Deliverables

- root-level Mode A packet with docs, CSVs, CAD/CNC, drawings, concept image, and site
- print packet in Markdown and HTML
- capstone deck in Markdown
- generated binary companions: `Wooden-Hang-Design.xlsx`, `capstone-deck.pptx`, and `print-packet.pdf`

# Recommended First Physical Prototype

Build `WHG-P2`: a three-note top-plate hybrid sector using a replaceable maple or birch-laminate top over a simple bowl with interchangeable port plugs.

Why this first:

- enough geometry to test cross-talk
- still cheap enough to rework
- honest bridge between coupon data and a full-layout promise

# Next Actions

- machine coupon and P1/P2 fixtures
- pick two top-material systems and keep all other variables controlled
- populate `validation.csv` immediately from the first strike tests
- promote only the geometry variables that survive measurement