# Drawing Brief

## Purpose

Create drawings that help a fabricator, tuner, and reviewer inspect the handpan prototype. These drawings should not imply that the tone fields can be machined to final pitch. They are layout, fixture, inspection, and communication drawings.

## Required Drawing Set

1. General assembly side view: two-shell lenticular body, 21 in nominal diameter, 9.5 in total height, rim joint, bottom Gu location.
2. Top layout view: Ding and eight field clock positions, note names, target fundamentals, and estimated oval layout envelopes.
3. Bottom view: Gu center, 3.5 in nominal port, lip/edge finish note.
4. Section view: shell thickness, rim bond region, Gu lip, and approximate internal volume region.
5. Fixture view: tuning support ring contact surface and shell support datum.
6. Template sheet: Ding and eight removable layout templates.
7. Validation overlay: measurement point map for thickness, strike positions, and microphone reference.

## Drawing Rules

- Mark all tone-field final shapes as `tuner adjusted`.
- Mark field dimensions as `layout estimates`.
- Include both inch and metric dimensions.
- Include datum references: shell center, 12 o'clock reference, rim plane, Gu center.
- Avoid CNC-style final contour dimensions for tuned areas.
- Add notes for inspection and measurement logging.

## CAD/CNC Deliverables

- `cad/handpan-cad-brief.md` for model setup.
- `cnc/fixture-cnc-brief.md` for support ring and templates.
- `drawings/drawing-index.md` for drawing list and review gates.