# Ngoni — Assembly Manual **Instrument:** Ngoni (Kamele N'goni) — Kamele 10-string primary case **Version:** v1.0 (pre-prototype) **Date:** 2026-05-08 > ⚠ This manual reflects the design intent. Mark each step ☑ as completed; add shop notes in the Notes column of your build log. --- ## Tools Required - Table saw with miter sled (18° stop) - Band clamp (10–14 in diameter range) - Wood lathe (12 in swing minimum; 16 in preferred for Kamele 14) - Bowl gouge, skew chisel, scraper - Drill press - 1.25 in Forstner or spade bit (neck-entry hole) - Spokeshave and rasp (neck profiling) - Calipers, steel rule, feeler gauge - Titebond III - Clamps (pipe or strap clamps for neck-to-bowl) - Electronic tuner (Korg OT-120 recommended) --- ## Phase 1 — Bowl Segments ### Step 1 — Set Up Miter Sled Set the table-saw miter sled to exactly **18°** (for 10-segment rings). Verify with a test ring: cut 10 scrap pieces and dry-fit into a closed ring. Check flatness with a straightedge. Adjust miter angle ±0.1° until ring closes without gap. **☑ Done? ________** Notes: _______________ ### Step 2 — Cut All Segments Cut segments per the ring cut list (cut-list.csv). Each of the 11 rings requires 10 segments; cut **11 per ring** (10% extra). Total: **121 segments**. Label segments by ring number immediately after cutting. **☑ Done? ________** Notes: _______________ ### Step 3 — Glue Rings Glue one ring at a time: 1. Dry-fit all 10 segments for the ring. Check closure (no gap > 1/32 in). 2. Apply Titebond III to both miter faces of each segment. 3. Assemble ring; wrap with a band clamp. Tighten evenly. 4. Check ring for flat on surface plate. Adjust before glue sets (≈ 10 min open time). 5. Let cure 1 hour before stacking next ring. **☑ Done? (ring 1) ________** ... **☑ Done? (ring 11) ________** Notes: _______________ ### Step 4 — Stack and Glue Rings Stack rings 1–11 (ring 1 = bottom, ring 11 = head rim). Glue each mating face with Titebond III. Clamp with band clamps or pipe clamps through the stack. Let cure 4 hours minimum. Verify each ring is oriented with wood grain running roughly parallel to the ring plane (not perpendicular, which would be weak in shear). **☑ Done? ________** Notes: _______________ ### Step 5 — Glue Base Plug Glue the base plug (NGO-B04) to ring 1. Clamp or tape. Let cure 2 hours. **☑ Done? ________** Notes: _______________ --- ## Phase 2 — Lathe Turning ### Step 6 — Mount Bowl on Lathe Mount the glued-up bowl blank on the lathe between centers, or using a large chuck jaw. Bring to concentric by slow rotation — expect initial imbalance. *Safety: bowl blanks are largest turning hazard. Start at lowest speed (< 500 RPM) until balanced.* **☑ Done? ________** Notes: _______________ ### Step 7 — True Exterior True the exterior with a bowl gouge. Target the parabolic profile in design.md Section 4. Target wall: **3/8 in** finished. Check outer diameter at each ring zone with calipers. Mark target diameters on tool rest with tape. **☑ Done? ________** Notes: _______________ ### Step 8 — Hollow Interior Hollow interior to match exterior profile, leaving 3/8 in wall. Use a bowl gouge then scraper for finish passes. Check wall thickness frequently with calipers. Stop if wall < 5/16 in anywhere — reinforce with thin veneer patch if needed. **☑ Done? ________** Notes: _______________ ### Step 9 — Drill Neck-Entry Hole Mark the neck-entry point at the top of the bowl (center of head-rim ring). Drill with a 1.25 in Forstner bit on the drill press. Drill perpendicular to the head-rim face. *The neck must pass through this hole and protrude 1.5 in inside the bowl.* **☑ Done? ________** Notes: _______________ --- ## Phase 3 — Neck ### Step 10 — Prepare Neck Blank Joint and plane the neck blank (30 in × 1.5 in × 1.5 in). Both faces must be flat and square. Mark the vibrating length (22 in from nut to bridge on the skin) and the bowl-entry zone (last 3 in). **☑ Done? ________** Notes: _______________ ### Step 11 — Shape Neck Profile Shape the neck to a round or D-profile (1.0 in diameter at the thickest point) using: - Bandsaw to knock off corners - Spokeshave or rasp to refine profile - Sandpaper 80 → 120 → 180 → 220 → 320 → 400 grit Leave the bowl-entry end slightly oversized. Test fit in the bowl neck hole; sand until snug press-fit (< 0.010 in play). **☑ Done? ________** Notes: _______________ --- ## Phase 4 — Bridge ### Step 12 — Shape Bridge Start from the 4 in × 2 in × 0.75 in bridge blank. - Crown the top surface with a gentle arch (convex upward, 1/16 in crown at center). - Mark 10 string notches at 8 mm spacing (centered on bridge width). - Cut notches: 1 mm wide × 1 mm deep (strings sit in notch but do not bind). - Flatten the bottom face. Verify sits flat on skin plane with no rocking. **☑ Done? ________** Notes: _______________ --- ## Phase 5 — Skin Head ### Step 13 — Soak Goatskin Soak the goatskin in room-temperature water 12–24 hours until fully pliable. Do not use hot water (degrades collagen). **☑ Done? ________** Notes: _______________ ### Step 14 — Stretch and Mount Skin 1. Drain skin; pat surface dry (not bone dry — still pliable). 2. Center skin over bowl rim (head-rim ring = ring 11). 3. Pull skin taut from opposing sides (N–S, then E–W) to achieve even tension. 4. Tack with 16 upholstery tacks spaced evenly around rim. 5. Work around circumference in a star pattern to equalize tension. 6. Let dry at room temperature 24–48 hours. *Do not force dry with heat — skin will shrink unevenly.* **☑ Done? ________** Notes: _______________ --- ## Phase 6 — Final Assembly ### Step 15 — Install String Anchor Drill two 3/8 in holes through the bowl base (opposing sides, perpendicular to neck). Thread the steel anchor rod (NGO-HW02) through. Bend or thread ends to secure. The strings will loop over this rod. **☑ Done? ________** Notes: _______________ ### Step 16 — Insert Neck Apply a small bead of Titebond III in the neck-entry hole. Insert neck until it protrudes 1.5 in inside bowl. Align neck with string anchor rod (same axis). Let cure 2 hours clamped. **☑ Done? ________** Notes: _______________ ### Step 17 — String Up 1. Loop each string around the anchor rod at the correct position. 2. Run string over bridge notch and up neck. 3. Tie tuning ring (konso) at the headstock end: wrap string 3× and cinch tight. The ring slides to adjust pitch. 4. Bring all strings to approximately correct tension starting with the middle strings (strings 5–6) first. 5. Let strings stretch and settle for 24 hours before fine tuning. **☑ Done? ________** Notes: _______________ ### Step 18 — Tune Tune to D–F–G–A–C pentatonic using an electronic tuner. Refer to validation.csv checks V-01 through V-10. Allow 48 hours of settling; expect significant pitch drop on first day as leather and strings stretch. **☑ Done? ________** Notes: _______________ --- ## Phase 7 — Finishing ### Step 19 — Sand and Finish Bowl + Neck Sand bowl and neck to 400 grit. Apply 2–3 coats of tung oil (let cure 8 hours between coats). **Do not apply oil to goatskin head** — will soften it and deaden tone. **☑ Done? ________** Notes: _______________ --- ## Post-Build Validation Run all checks in validation.csv. Sign off each V-xx check. File completed validation.csv in data/ folder. | Check | Description | Pass? | |---|---|---| | V-01 to V-10 | String tuning ±5 cents | | | V-11 | Neck deflection < 0.050 in | | | V-12 | Wall thickness ≥ 5/16 in | | | V-13 | Bridge stability | | | V-14 | Skin tension uniform | | | V-15 | No open ring gaps | | | V-16 | Neck fit in bowl | | | V-17 | Ergonomic reach | |