Three things that bug me about printed rulers, so I designed one that fixes them
Most 3D-printed rulers I've found on MakerWorld have three problems:
- The edge is too thick to draw a clean line against with a pencil.
- Zero starts a few mm in from the end, so you can't butt it against the feature you're measuring from.
- Single-color only, or they require an AMS for any contrast on the markings.
I designed one that fixes all three issues. The edge has a comb structure that thins the working edge for pencil work while the body stays 3mm thick for rigidity. Both ends are flush — zero is at the contact point. The multi-color version uses a single manual filament swap at one layer, so it works on any Bambu printer including the A1 Mini, no AMS required.
Three sizes in one project: 10/15/20 cm. PLA prints fine on a 0.4mm nozzle. PETG needs 0.2mm — the 0.4 clumps on the fine comb features.
Hardest part was getting the swap layer right so all the numerals and tick marks switch cleanly without disrupting the body. It took a dozen iterations to land it. But now I am using them all the time and one is even in my EDC kit.
Numbers are added via MakerWorld's text feature, so the model is best used by importing the project into Bambu Studio rather than downloading the raw STL. This also means you can customize the numerals if you want a different font, language, size, etc.
Happy to answer questions on the design or the slicer setup.