Braille Cylinder STL Generator
A web app for generating 3D-printable braille. Type your text, pick a braille translation table, and download an STL file you can send straight to your 3D printer.
The goal is to make embossed braille business cards accessible to anyone with a 3D printer, without needing to know braille yourself. The app handles translation (via liblouis) and turns it into a ready-to-print 3D model.
What it does
- Translates text to Grade 1 or Grade 2 braille across 50+ language tables
- Generates STL files for the two cylinders of a hand-operated braille card embosser
- All STL generation runs in the browser — nothing gets uploaded
- Shows a 3D preview before you download
- Embosses both faces of a card in one pass when Double-sided is chosen
Flat business card plates are parked, not in development here — the code is
still in the repo but disabled in the UI. See
KNOWN_ISSUES.md for why. Directly readable braille cards
already ship as their own tool:
braille-wedge-card-openscad.
Slicer seam channel
Every cylinder carries a shallow groove (1 mm wide, 0.5 mm deep) the full height of its
outside: beside the row markers in Visual mode, down the alignment-arrow column in Tactile
mode, where it steps around the raised arrows so they stay whole. A slicer's default "Aligned" seam mode hides each layer's
seam in that groove instead of in a braille dot, so no seam painting is needed; leave the
seam mode on Aligned. It can be turned off under Expert Mode → Surface Dimensions. Details
in SURFACE_DIMENSIONS_SPECIFICATIONS.md.
Embosser setup
The first item on the page, Embosser setup, holds three either/or choices that pick
which of the four released embosser projects your cylinders are made for: the embosser
version (Version 1 prints the most accurate dots; Version 2 adds tactile row markers and
a simpler assembly for blind users), the gears (Standard: printed separately, or
Simplified: fixed to the cylinders, which saves parts but prints longer and fails dots more
often), and the card sides. A "Which setup should I choose?" link opens the help guide.
Double-sided cards
Choosing Double-sided under Embosser setup makes both cylinders emboss: each carries the
raised dots for one face and the recesses for the other. Run a card between them and it
comes out with braille on both faces in a single pass.
Choosing it enables the Back of Card section for the back text, and locks the Row
Indicator Style to the tactile seam arrow, which both cylinders of a pair need. The back
text wraps across the rows for you, the braille preview then shows both sides, and the two
sides sit on grids offset diagonally by 1.25 mm so a dot on one face never lands where a
dot on the other face already is.
It has been printed and used: in August 2026 two rounds of pairs were printed on a Bambu
Lab X1C with a 0.4 mm nozzle and embossed real card stock, legible on both faces.
Step-by-step instructions are in
Double-Sided Cards.
The device these cylinders go into
The cylinders this app generates are the interchangeable plates for the
Custom Braille Embosser — a hand-operated braille embosser built from ten
snap-fit 3D-printed parts, with no fasteners, springs, glue, or electronics, for
about $3–6 of filament. Generate an embossing plate and its matching counter
plate at the same card-stock thickness, print both, and snap them into the
holders.
Build files, print profiles, and documentation for the device are on
Printables,
MakerWorld,
and Thingiverse.
Embosser Version 2. The version choice under Embosser setup switches the
generator to Version 2, whose cylinders are keyed at both ends so a drive gear
cannot be seated in the wrong place, and which carries tactile row markers a blind
user can feel. Its gears must be cut to the R14 peg spec — earlier pegs do not fit.
Version 1 stays the default and is fully supported; see
KNOWN_ISSUES.md.
Quick start
Using the hosted app
Open https://braille-cylinder-stl-generator.vercel.app — nothing to install.
Running locally
pip install -r requirements.txt
python backend.py
Open http://localhost:5001 in your browser.
Deploying to Vercel
- Connect the repo to Vercel
- Deploy
That's it. No Redis, no blob storage, no API keys to manage. The server just serves static files and a lightweight JSON endpoint — all the heavy geometry work happens in your browser.
You can optionally set PRODUCTION_DOMAIN as an environment variable, but it's not required. See Environment Variables if you're curious.
How to use it
- Under Embosser setup at the top of the page, choose your embosser version, gears
and card sides
- Type your text (up to 4 lines)
- Pick a braille translation table and grade
- Check that Card Thickness in Expert Mode matches your card stock (0.4 mm by
default); the preset sets the cylinder size and dots for you
- Press Generate STL — it builds both cylinders, A and B
- Press Download STL when it appears: one file with both cylinders spaced for one
print plate. Print it and emboss the card between the two cylinders.
Want just one cylinder? Open Expert Mode and choose it under Cylinders to
Generate, the first submenu; Download STL then saves that cylinder on its own. For a
double-sided card, choose Double-sided under Embosser setup in step 1 and
type the back text into the Back of Card box — the back has its own Auto / Manual
placement and per-line translation choices, exactly like the front. Nothing ever downloads on its own — one
press of Download STL saves one file.
There's a Help button inside the app that walks you through choosing what to include, formatting your text, and choosing your embosser setup. For more depth, check the guides below.
OpenSCAD version
Prefer working offline or want full parametric control? The OpenSCAD version is
maintained in its own repository —
braille-cylinder-stl-generator-openscad
— and a copy of its latest release is vendored into OpenSCAD/
here so you can download it without leaving the site.
Issues and pull requests for the OpenSCAD program belong upstream. Nothing in
OpenSCAD/ should be edited here — tests/test_vendored_openscad.py fails if it is.
The web app translates automatically; the OpenSCAD version needs you to translate manually (using Branah.com), but it works without an internet connection and integrates with existing CAD workflows.
As of v2.6.0 the OpenSCAD companion includes double-sided (interpoint) cards as well,
with the same paired Cylinder A / Cylinder B workflow. Back-of-card text there is
pre-translated braille only, like the front — automatic translation stays a web-app feature.
Project layout
app/ Flask backend, geometry specs, validation
public/ Production HTML (served on Vercel)
static/ Frontend JS, CSS, Web Workers, liblouis tables
tests/ Smoke tests and golden file regression tests
docs/ Guides, technical specs, deployment notes
See PROJECT_STRUCTURE.md for the full breakdown.
Development
Requires Python 3.12+.
pip install -r requirements-dev.txt
# Run tests
pytest
# Lint and format
ruff check .
ruff format .
Pre-commit hooks are included — run pre-commit install to set them up.
Guides
Using the app:
- Cylinder Guide — the cylinders and their settings, printing tips, and double-sided cards
- Business Card Guide — what to include and formatting rules, quoted verbatim from the BANA Business Cards Fact Sheet (approved March 2024). Flat cards are parked; the formatting rules still apply to cylinder text.
Working on the code:
Contributing
Contributions are welcome. See CONTRIBUTING.md for setup instructions and guidelines.
Acknowledgments
This project started from tobiwg/braile-card-generator by Tobi Weinberg. Thanks to Tobi for getting it off the ground.
Changelog
See CHANGELOG.md for release history.
License
PolyForm Noncommercial License 1.0.0
Free for personal, educational, and non-commercial use. Modification and remixing allowed. No commercial use.
