START HERE - Lactic Acid (CAS 50-21-5) - READY TO PRINT - ANT HOUSE 2026-10-29 (procedure v7)
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A model of the lactic acid molecule on a display base, printable in one go on a
standard FDM printer (0.4 mm nozzle, PLA). No 3D-printing experience needed.

THE SHORT WAY (3 steps)
  1. Open lactic-acid_50-21-5_ANT-HOUSE.3mf in PrusaSlicer (answer YES to "load configuration").
  2. Choose your printer, press A (Arrange), click Slice, check the preview (REMOVE_KEEP.png).
  3. Print at 100 % (do not scale). 3MF profile: about 13h 0m 36s, about 125 g PLA (ready G-code: 130 g).
  Details: PRINT_INSTRUCTIONS.txt.  Ready G-code for some printers: gcode/.

WHAT IS IN THIS FOLDER
  lactic-acid_50-21-5_ANT-HOUSE.3mf            model + our slicer settings (open this)
  lactic-acid_50-21-5_ANT-HOUSE.stl            model only (for any slicer)
                                               (= molgod-50-21-5-ready-to-print.stl from the website: same file, same SHA-256)
  gcode/                                       ready G-code for named printers + README
  PRINT_INSTRUCTIONS.txt                       step by step, settings, after printing
  PRINT_METHODOLOGY.txt                        why it is designed this way, checks, sources
  REMOVE_KEEP.png                              what to cut off and what to keep
  previews/                                    renders of the finished model + the same views
                                               "as-printed" (with slicer supports) and "after-removing-supports"
  slicer_profile.ini                           all settings (PrusaSlicer format)
  GATES_REPORT.txt                             results of our checks on this exact file
  QC_CHECKLIST.txt                             how to check the finished print
  FEEDBACK_FORM.html                           tell us how it printed
  PROVENANCE.txt                               where the atom positions come from + what we changed
  source/                                      the PubChem 3D source file (SDF)
  LICENSE.txt                                  licence and attribution
  SHA256SUMS.txt                               checksums of every file

THE MODEL
  Base: diameter 130 mm, 20 mm high, raised MolGod logo on top, name and CAS on
  the front, data and QR code (https://molgod.org/molecule/50-21-5/) underneath.
  Molecule: scale 1 A = 20.49 mm; 7 vertical hexagonal pencils with
  45-degree cups carry it - they are part of the model, keep them.
  Size 130 x 130 x 96 mm, 282598 triangles.

WHERE THE GEOMETRY COMES FROM
  Atom positions: PubChem CID 612, conformer 0000026400000001. COMPUTED by PubChem
  (PubChem3D, using OMEGA) - one calculated conformer, not an experimental
  structure. All 6 hydrogen atoms are shown. Molecule-geometry gate on this file: PASS.
  Details: PROVENANCE.txt.

VERIFY THE FILE
  SHA-256 of lactic-acid_50-21-5_ANT-HOUSE.stl: 4ed73c7c99b958a71d93bf9d9c370ee7507cd1a346e2789745d6978df8dd1676
  Windows: certutil -hashfile lactic-acid_50-21-5_ANT-HOUSE.stl SHA256  |  macOS: shasum -a 256 ...  |  Linux: sha256sum ...

STATUS
  Checked by geometry tests and slicer simulation of this exact file
  (GATES_REPORT.txt). Not yet confirmed by a physical print of this release.
  Licence: CC BY-NC-SA 4.0 (LICENSE.txt). Model page: https://molgod.org/molecule/50-21-5/
