Parametric Snap-Lock Box with Custom Compartments (FreeCAD)

A snap-lock storage box where YOU decide the compartments: type letters in a FreeCAD spreadsheet, press Ctrl+R, export, print. Perfect for screws, nuts, bolts, SMD parts, beads or fishing tackle.

Why it is different

• Draw the layout like a map: one letter = one compartment, the same letter in neighbouring cells = one merged compartment (L-shapes are fine).

• Column widths and row lengths are proportions, so the layout scales when you resize the box.

• The walls go from the floor all the way up to the lid ceiling (0.3 mm gap), so parts cannot jump between compartments when you shake the box during transport.

• Wall tops near the front are automatically trimmed along the hinge arc: the lid still opens and closes freely.

• Wall thickness (default 2 mm) and lid clearance are parameters too.

• The whole box is parametric: inner width/length, bottom and lid heights, corner radius. Hinges and latches adapt automatically (one centred hinge/latch on small boxes).

Ready-to-print files (200 x 90 mm inside, 20 + 18 mm high)

• 4 bottoms: 3 bins, 8-cell grid, 10 bins (9 small + 1 big), 12 small bins

• 1 lid, 1 latch (print 2)

Make your own layout (FreeCAD 1.1)

1. Download parametric_box_compartments_FreeCAD.zip.

2. Copy BoxCompartments.py into your FreeCAD user Mod folder: Mod/BoxCompartments/BoxCompartments.py, then restart FreeCAD (without it the walls are not recomputed). Details in README.txt.

3. Open parametric_box_compartments.FCStd.

4. Box size: sheet Parameters (green cells: Inner_width, Inner_length, Bottom_height, Top_height...).

5. Compartments: sheet Compartments_Layout. B1 = wall thickness, B2 = lid clearance, B3 = 1/0 walls on/off. Row 5 = column widths, column A = row lengths, letters from B6. Row 6 is the hinge side, seen from above.

6. Ctrl+R, then export BOTTOM_Comp, TOP and Latch_R as STL.

Print settings

• PLA or PETG, 0.2 mm layers, 3 perimeters, 15 % infill.

• Bottom: floor on the bed. Lid: ceiling on the bed. Latch: flat face on the bed. No supports needed.

• The hinge and latch clearances come from the tested original and print well as-is.

Note: the coloured floors in the pictures only identify the compartments in the renders; the model is single-colour.

Credits: original SnapLock V3 design by Hugo (MakerWorld), remixed and published with his permission. Parametric FreeCAD rebuild and compartment system made with the help of AI (Claude).