# Drawing Brief

## Drawing Set

| Drawing | Purpose | Required datums |
| --- | --- | --- |
| `drawings/ghb-chanter-front.svg` | Chanter body, tone-hole datum chain, bore section | Datum A = sole/bell end, Datum B = reed seat axis, Datum C = front hole line |
| `drawings/ghb-drone-set.svg` | Tenor and bass section lengths, bores, tuning-slide interfaces | Datum A = reed seat end, Datum B = slide shoulder, Datum C = sound exit |
| `drawings/ghb-pressure-interface.svg` | Bag, stocks, blowpipe, valve, pressure path | Datum A = bag centerline, Datum B = stock tie-in groove |
| `drawings/ghb-system-validation.svg` | Validation flow: pressure, leak, drone tuning, chanter tuning, maintenance retest | Datum A = subsystem test order |

## Standards

- Units: inches with metric equivalents added later where useful.
- Default tolerance: +/-0.005 in for turned acoustic features; +/-0.015 in for
  decorative exterior features; fit-specific tolerances must be measured from
  purchased reeds and bag hardware.
- Critical dimensions must trace to `great-highland-bagpipe-design-table.xlsx`
  or measured supplier parts.
- Any reed-seat or stock dimension not measured yet is marked "measure chosen
  part" rather than guessed.

## Chanter Notes

The tone-hole coordinates in the workbook include measured practice-chanter
locations and first-pass target full-chanter values. The drawing must show
undersize drill diameters and leave final tuning by measurement.

## Drone Notes

Drone drawings must show effective acoustic length separately from physical
section length. Tuning slides, reed seats, and cap geometry move the acoustic
endpoint.