Print files
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Print-ready parts for all 20 mechanisms, one folder per mechanism in force-rank order. Every STL is already turned the way it should sit on the bed. Each folder also has parts.png (the parts laid out) and a STEP file with the printed parts in their assembled positions, for editing in CAD.
These are first prototypes, drawn from the concept models and the design guidelines but not yet printed and tested. Print one set and check the fits before printing more.
Settings
- ASA for every rigid part (PETG for indoor tests). 0.2 mm layers or finer on a 0.4 mm nozzle, at least 4 walls, 40 % infill; 100 % infill where a part's note says so (cams, levers, bosses).
- TPU 85A for the seals (the closest sold in Greece is 87A), 100 % infill.
- Supports only where a part's note says so.
- Each part's orientation follows the research rule: loads along the layers, pin axes vertical where it matters, hooks and snap arms lying on their side.
Fits
| Feature | Printed size | For |
|---|---|---|
| Pin bores | pin + 0.25 mm (4.25, 5.2) | a pin that turns; drill to size if tight |
| Press holes | 3.9 mm | 4 mm steel pins pressed into a lever |
| M3 clearance | 3.4 mm | screws through a part |
| M5 clearance | 5.5 mm | studs and bolts through a part |
| Hex pockets | nut width + 0.15 mm | M5 nuts (8 mm), nyloc nuts, M3 and M5 hex screw heads |
| Square nut slots | 5.7 × 2.0 mm | M3 square nuts (DIN 562, 5.5 × 1.8 mm) |
| Seal groove | 1.8 × 1.0 mm | the 1.5 × 3.4 mm TPU strip, squeezed 0.8 mm |
Screws into the box
Parts on the box wall use M3 screws into M3 square nuts. The box coupons show how: an inside pillar where the wall is 10 mm thick, with a 5.7 × 2.0 mm channel for each nut that drops in from the rim. The channels open on the rim between the seal and the outside, and the screw holes stop inside the wall, so no hole connects the outside to the inside of the box. Each nut has 3 mm of plastic in front of it. A nut slot that opens into the box would let water in along the screw thread.
Folders
Rebuilding
From the repo root, with FreeCAD 1.x and Blender 4.2+:
/Applications/FreeCAD.app/Contents/Resources/bin/freecadcmd -c "exec(open('print/build_print.py').read())"
blender -b --factory-startup -P print/render_print.py
python3 print/flatten_png.py
python3 scripts/build_docs.py
build_print.py refuses to write a mechanism whose printed parts overlap each other or the bought hardware. ONLY=id1,id2 rebuilds a subset.