BACH CLASSIC 1-1/2C MOUTHPIECE COMPONENT — ATTRIBUTION AND MODIFICATION RECORD

Original work
Title as archived: 1-1/2C Bach Trumpet Mouthpiece (45177)
Creator: Nick (N314)
Original source: https://www.thingiverse.com/thing:45177
Public archive: https://archive.org/details/thingiverse-45177
Archived metadata: https://archive.org/metadata/thingiverse-45177
Original publication date recorded by the archive: 2013-01-29
Source file: thingiverse-45177/Untitled/15c15c15c.stl
Source SHA-256: 581003ce2a0481fa43bdf2170ab3b488cae49d91f3a612ca106c78904adb5f4a

License
Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0).
License URL: https://creativecommons.org/licenses/by-sa/3.0/
Legal code: https://creativecommons.org/licenses/by-sa/3.0/legalcode.en
A complete copy is included as LICENSE-CC-BY-SA-3.0.txt.
The source license and creator/title are recorded in the retained public
archive metadata, thingiverse-45177-metadata.json.

Adaptation
Prepared for Mathew Harwich's Blender trumpet project with Codex assistance.
The mouthpiece component and its reconstructed profile are adaptations of
N314's work and are distributed under CC BY-SA 3.0.

Changes in the corrected derivative:
- Extracted an ordered closed meridian from an actual central section of
  the source STL and reconstructed it as a higher resolution lathed mesh.
- Preserved the source's classic outer rim, cup shoulder, neck and turned
  bead profile, and the visible cup form. The original non-axisymmetric
  size stamp was excluded by the selected meridian; editable circumferential
  VINCENT BACH 1-1/2C lettering was added using official product photographs
  as a visual reference. Font, depth and wrap are visual estimates.
- Normalized the axial length from 87.4000206 mm in the source STL to
  87.3125 mm (3-7/16 inches), the published general Bach #351 blank length.
  Radial dimensions were not globally scaled.
- Fitted the terminal exterior shank to the published general #351
  dimensions: 9.7028 mm (0.382 inches) at the tip and 10.9728 mm
  (0.432 inches) at 25.4 mm (1 inch) from the tip, yielding a 1:20
  diametral taper over that terminal segment.
- Replaced the source's approximately 5.20586 mm minimum internal diameter
  with the Bach nominal #27 throat diameter of 3.66 mm. The transitions
  into the source-derived cup and backbore are authored visual estimates.
  The source upper cup is retained through 9.0 mm from the lip; a smooth
  transition reaches the 3.66 mm throat from 14.9 to 16.9 mm; another
  smooth transition rejoins the source backbore at 34.0 mm. These axial
  locations and transition shapes are estimates. This does not reproduce
  a published factory internal CNC profile.
- Added editable silver appearance, finish variation, machining and wear
  details within the trumpet scene. These are artistic treatment, not
  measurements of a particular historical mouthpiece specimen.

Accuracy and source boundary
N314 described the original as a model of the author's own 1-1/2 mouthpiece.
A calibrated scanning or measurement method was not documented. The source
mesh and this adaptation are visual references, not fabrication-ready or
acoustically certified Bach CAD. The factory length, terminal shank and
nominal throat values above come from Bach-authored manuals retained in this
folder; those are general published dimensions, not manufacturing tolerances
for every 1-1/2C specimen. Bach's approximate nominal cup diameter is 17.0 mm;
it should not be conflated with a scanned specimen's differently defined
cup diameter or the aperture at the front plane of the rounded rim.

Component license boundary
This notice identifies the sourced mouthpiece geometry, extracted meridian
and adaptations of that component. Other trumpet geometry, lighting, code,
materials and research downloads have their own provenance and terms; this
notice is not a blanket license grant for every file in the project.
Bach/Yamaha names and marks identify the depicted products. This notice does
not grant trademark rights or imply endorsement by N314, Bach, Conn-Selmer
or Yamaha. Official product photographs and manuals are retained as reference
material; no open redistribution license for those images is asserted.
Unused downloaded models, including noncommercial alternatives, are not
incorporated through this attribution and retain their own license terms.
When sharing this component or an adaptation, retain appropriate credit,
source and license information and identify modifications.

License-copy provenance
The legal code was copied without modification from Creative Commons'
official cc-legal-tools-data repository:
https://raw.githubusercontent.com/creativecommons/cc-legal-tools-data/main/legacy/legalcode/by-sa_3.0.txt
License-copy SHA-256: 3f941b3b89cf7b8370ceb83cc76d2120d471b58735d8ca60238a751a48d7f72f

Research record date: 2026-10-23