Donation QR Codes

3D-printed QR code for donations

Around Noisebridge you will see many 3D-printed QR codes that streamline the donation process, allowing people to do one-off Apple Pay, Google Pay, and credit card donations.

How to create a QR Code

2D

You can quickly make a donation QR code for printing on paper or use in digital media with the QR Code Editor hosted on the Noisebridge donation portal. Make sure to do a quick test of the QR code with a phone as it's possible the logo cut-out renders the QR invalid.

3D

You can download some pre-generated QR code models from here.

Generating the STL files for a 3D-printed QR code is very compute intensive. That means it's not reasonable to provide this functionality on the donation portal website. However, there is a script that generates everything with one command.

1. First clone the git repository

git clone git@github.com:noisebridge/donate-portal.git

2. Follow the setup instruction in the README.md. The project requires values for each environment variable in a .env file you must create in the repository root, but for the purpose of this script those values can all be bogus.

3. Run the script.

bun run generate-openscad-qr --amount 13.37 --text-lines '["Give a","Shit.","Donate"]' --name 'A Shit' --description 'You get what you give!'

There are a few constraints:

• The script keeps the pixels in the QR code the same size as the pixels in the text, so it requires the QR code be of a certain width. You may need to add or remove data from the --name and --description parameters, which are encoded into the QR code.
• The font has a limited character set. Only the upper/lower alphabet, numerals, $, /, :, . are supported.
• The text lines can only be so long. The hard-coded limit is 9 characters per line but that does not guarantee the text fits.

This takes about 5 minutes on my computer so give it some time. The entire process is single-threaded, so feel free to run multiple at once.

4. You should now have 3 STL files in scripts/openscad/qrs named something-black.stl, something-red.stl and something-white.stl. Import these STLs into your 3D slicer as one object with multiple parts and assign each part a filament of an appropriate color.

Specifically for Bambu Studio:

• File > Import > Import 3MF/STL/STEP/SVG/OBJ/AMF/...
• Select all 3 STL files
• Select "Yes" when asked "Load three files as single object with multiple parts?"
• Add 3 filaments (ex: "Generic PLA"). One for red, black and white.
• In the "Objects" panel expand your object in the list and assign the colors to the 3 parts (you can do this with the numbers on your keyboard that correspond to the filaments).
• In the "Global" settings panel go to Strength > Sparse Infill Density and set to "100%". This helps with materials that can be slightly translucent so you can't see the infill pattern.

5. Flip the objects upside-down. The print quality is much higher when the display side of the print is pressed into the print bed.