Parametric Finger Splint

Parametric Finger Splint (OpenSCAD)

A fully parametric, curved finger splint designed in OpenSCAD. Fits snugly around the finger with a clamshell-style slit along the top for easy on/off, and a parabolic fingernail opening at the tip for comfort and airflow. This splint immobilizes the joint closest to the tip. I have no medical training, so use at your own risk!

Features:

Bezier-curved spine follows the natural upward curve of the fingertip

All dimensions are interior measurements — just measure your finger and plug in the numbers

Oblong ventilation holes in a staggered brick pattern, oriented for minimal bridging when printing vertically

Parabolic tip scoop eliminates sharp corners at the fingernail opening

Customizer-ready with organized parameter groups

Key Parameters:

Finger length, width, and height at base and tip

Curve shape (tip rise and bend position)

Wall thickness, slit width, and nail opening length

Ventilation hole size, spacing, and pattern density

Printing Tips:

Print upright with the base opening on the build plate

No supports needed — oblong vent holes are oriented to minimize bridging

TPU or PETG recommended for flexibility; PLA works for rigid splints

Secure with a wrap of self-adhesive bandage or a small Velcro strap

Use the OpenSCAD Customizer to save parameter sets for different finger sizes.

Save the following in a json filed with the same name as the scad file (finger-splint-curve.json). These parameters worked well for a swollen pinky finger. 

{
    "fileFormatVersion": "1",
    "parameterSets": {
        "small finger": {
            "$fn": "48",
            "base_height": "17",
            "base_width": "19.5",
            "curve_apex": "0.5",
            "hole_ang_step": "25",
            "hole_dia": "2",
            "hole_length": "3",
            "hole_margin": "5",
            "hole_spacing": "6",
            "nail_open_length": "11",
            "nail_scoop": "7",
            "slices": "100",
            "slit_clearance": "3",
            "split_gap": "3",
            "tip_height": "13",
            "tip_rise": "7",
            "tip_width": "15",
            "total_length": "33",
            "wall": "2"
        }
    }
}