Floor Harp Build Packet Print Packet

Generated: 2026-05-09

Packet folder: `/tmp/floor-harp-codex-gina-r2-build-packet`

File Map

design.md

Project intent, catalog metadata, assumptions, and validation plan.

Floor Harp Design

Intent

Create a practical L2 packet for a small floor-standing harp that is large

enough to test graduated string lengths, frame stiffness, and ergonomic reach

without claiming concert-harp maturity.

Readiness

L2 scaffold. This packet can support CAD layout and sourcing review, but the

frame must be analyzed and proofed before a full string load is applied.

Governing Model

Strings use Mersenne-Taylor:

f = (1 / (2 L)) * sqrt(T / mu)

The harp also needs a structural load model because cumulative string tension

dominates the neck, pillar, soundboard, and base joints.

Baseline Assumptions

Tension Safety Notes

• Do not bring a prototype to full pitch until neck, pillar, and base joints

have passed dry-load review.

• String from low to high in stages while checking frame movement.
• Keep the body out of the string plane during initial pitch-up.
• Add a proof-load hold point before final tuning.

Known Gaps

• No final string chart or lever/sharping plan.
• No frame FEA or physical proof-load result.
• No soundboard deflection data.
• No sourceability/pricing check.
• No prototype tuning record.

bom.csv

Starter bill of materials with part categories, quantities, drawing refs, and notes.

sourcing.csv

Supplier/search tracker with specs, price/date fields, lead time, substitutes, and risks.

cut-list.csv

Rough/final stock sizes, material, grain/orientation, operations, yield, and offcuts.

drawing-brief.md

Manufacturing drawing and technical product sketch brief.

Floor Harp Drawing Brief

Required first drawings:

• Full-size side elevation with neck, pillar, base, soundboard, and string fan.
• String chart with note, frequency, scale length, gauge, and target tension.
• Neck drilling layout with pin spacing and edge distances.
• Pillar/base joint detail.
• Soundboard section with bridge strip, string angle, and rib layout.

assembly-manual.md

Shop-facing sequence, tools, fixtures, safety, tuning, finishing, and maintenance notes.

Floor Harp Assembly Manual

1. Lock the string chart and full-size side elevation before cutting.

2. Build neck and pillar from clear stock or laminations with conservative

glue area.

3. Dry-fit neck, pillar, and base, then mark string paths and pin locations.

4. Build the soundbox/soundboard assembly and verify flatness.

5. Fit bridge strip, guide pins, and string holes without sharp edges.

6. Test tuning pin pilot holes in offcuts before drilling the neck.

7. Assemble frame and soundbox, then finish before final hardware if practical.

8. String gradually in stages, recording frame movement after each stage.

Safety: treat the first full string-up as a proof test. Wear eye protection and

stand out of the string plane.

validation.csv

Target/measured values, tolerance, environment, result, and tuning/build action log.

supplier-rfq.md

Supplier email/request-for-quote starter.

Supplier RFQ Draft

Hello,

Please quote hardware and strings for a 22-string small floor-harp prototype

covering approximately C3 through C6. I need individual string gauges with

tension data, compatible tuning pins, and bridge pins or eyelets.

Please include material specifications, rated tension or breaking strength,

unit price, minimum order quantity, lead time, and shipping options.

visual-bom-brief.md

Art direction for an image-forward visual BOM.

Visual BOM Brief

Show the full harp silhouette with callouts for neck, pillar, base, soundboard,

back/shell, bridge strip, tuning pins, guide pins, string set, adhesive, and

finish. Include a detail inset for the string path through pin, guide, bridge,

and soundboard.

floor-harp-starter.wl

Wolfram starter for physics, optimization, visualization, and validation.

(* Floor harp string schedule starter. Values are first-pass assumptions. *)
ClearAll["Global`*"];
a4 = 440;
freqFromMidi[m_] := a4*2^((m - 69)/12);
notes = Range[48, 84]; (* C3 through C6 chromatic range; select diatonic rows later *)
scaleLengthIn[m_] := 13 + (42 - 13)*(84 - m)/(84 - 48);

Dataset[
  Table[
    <|"midi" -> m, "frequencyHz" -> N[freqFromMidi[m]],
      "firstPassScaleLengthIn" -> N[scaleLengthIn[m]]|>,
    {m, notes}
  ]
]

README.md

Project artifact.

Floor Harp

Engineering documentation and parametric design table for a floor-standing concert-style harp.

Part of the [tonykoop/instrument-maker](https://github.com/tonykoop/instrument-maker) catalogue.

Readiness

L2 scaffold. This repo now contains root-mode build packet documentation for a

small floor-harp prototype. It is not L3 because string schedule validation,

frame-load analysis, CAD renders, sourceability checks, and measured prototype

data are still open.

Packet Contents

• `design.md` - design basis, string schedule assumptions, and structural gaps.
• `bom.csv`, `sourcing.csv`, `cut-list.csv`, `validation.csv` - packet tables.
• `assembly-manual.md`, `risks.md`, `photo-shotlist.md` - build and review aids.
• `drawing-brief.md`, `drawings/README.md`, `cad/README.md`,

`floor-harp-starter.wl`, `wolfram/README.md` - starter technical artifacts.

String-Scale Assumptions

Baseline: 22 strings from C3 to C6 diatonic, graduated speaking lengths from

about 42 in bass to 13 in treble, nylon/fluorocarbon/wound bass strings as

needed, and a frame designed conservatively before any full-tension string-up.

License

[CC BY 4.0](LICENSE) - see LICENSE for details.

photo-shotlist.md

Project artifact.

Photo Shotlist

• Full-size side elevation with string fan and frame members.
• Neck and pillar grain or lamination layout before cutting.
• Dry-fit frame joints before glue.
• Tuning pin scrap test with bit sizes labeled.
• Soundboard bridge/string-hole detail before stringing.
• Staged string-up with frame movement measurements.

risks.md

Project artifact.

Floor Harp Risks

• Cumulative string tension can damage the frame or injure the builder if the

neck, pillar, or base joint fails.

• Tuning pin torque and holding power are unknown until scrap tests are done.
• Soundboard deflection is not validated.
• Long clear hardwood and harp strings may have cost/lead-time surprises.
• Remain at L2 until structural review, sourceability, and prototype tuning

evidence are available.