# Drawing Brief

## Required Sheets

1. Overall G4 body elevation with head datum, foot datum, window setback, and
   all tone-hole stations.
2. Bore and block section showing removable fipple block, windway height, and
   leak-control surfaces.
3. Window/labium detail with windway width, window length, ramp angle, and edge
   note.
4. Drill jig/story-stick layout for repeatable hole placement.

## Datum Scheme

- A: bore centerline.
- B: foot end after square trim.
- C: top surface orientation through window and front holes.

All tone-hole stations are measured from datum B. Window and block dimensions
are measured from the head end and cross-checked to datum A.

## Tolerance Notes

- Bore ID is measured, not assumed from nominal pipe size.
- Tone holes start undersize; final diameters are validation outputs.
- Windway height is a controlled empirical variable and should be called out as
  adjustable on the drawing.