# Wooden Hang Assembly Manual

## Scope

This manual covers the first Wooden Hang research builds, with the top-plate hybrid path treated as the default shop path. It also notes where the split-shell CNC and segmented/stave variants diverge.

## Tools And Setup

- CNC router or careful template-routing workflow
- table saw, band saw, planer, drum sander, drill press, hand sanding blocks
- calipers, scale, moisture meter, tuner, microphone, and repeatable recording setup
- clamps and cauls for laminated stock
- removable-top fixture hardware and gasket material
- shop notebook or digital log for every measured test

## Process

1. **Prepare a coupon matrix**
   - Cut matched coupons in at least two wood systems.
   - Vary thickness, grain direction, and isolation geometry one variable at a time.
   - Record moisture content before every strike test.

2. **Establish one note-zone method**
   - Compare at least three approaches:
     - underside-thinned plate field
     - slit tongue
     - hybrid undercut plus shallow slot relief
   - Choose the method with the clearest pitch and most controllable rework path.

3. **Build the single-field cavity rig**
   - Make a small removable-top bowl or test box.
   - Keep top fastening outside the active field.
   - Add interchangeable port plugs so cavity tuning can change without remaking the body.

4. **Measure before tuning by feel**
   - Strike and record the field in free state and mounted state.
   - Log frequency, cents offset, decay, and audible sympathetic behavior.
   - Only then make a controlled geometry change.

5. **Build the three-note sector**
   - Use the same datum scheme planned for the full instrument.
   - Keep at least one spare sector top blank.
   - Test realistic hand spacing and note interaction before any full-layout commitment.

6. **Escalate to the five-note subset**
   - Build the subset only after P2 results suggest a correction path.
   - Confirm that the chosen top species or laminate schedule stays dimensionally stable across a few days of shop humidity swing.

7. **Assemble the full-layout body**
   - Route or build the lower bowl.
   - Fit the removable or semi-permanent top plate.
   - Add the port, support feet, and cradle interface.

8. **Tune conservatively**
   - Remove material in tiny steps from underside relief areas first.
   - Avoid aggressive thinning at strike centers until the trend is understood.
   - If a field goes unstable, stop and document the failure instead of forcing it.

9. **Finish only after baseline measurements**
   - Test finish on coupons first.
   - Keep strike zones raw or lightly sealed during early acoustic tests.

10. **Package the measurement loop**
   - Update `validation.csv` after every build stage.
   - Carry the winning geometry variables forward into the next prototype rather than relying on memory.

## Split-Shell CNC Variant Notes

- Machine sequence: upper inside, lower inside, upper outside, lower outside.
- Use alignment pins or repeatable registration holes between operations.
- Leave extra tuning stock on the upper playing shell until early acoustic behavior is known.

## Segmented / Stave Variant Notes

- Use the stave shell primarily as a body-volume experiment paired with a replaceable top.
- Do not let shell join complexity hide the top-note-zone measurement loop.

## Shop Notes

- The first successful result is a **repeatable trend**, not a perfectly tuned full instrument.
- Keep hardware, gaskets, and support points outside the strongest vibration regions.
- Track humidity and temperature because wood pitch drift can masquerade as geometry error.
- If the hybrid path works well enough, keep it as the family identity instead of forcing a more steel-like shell.