Three Small Prints — 3D Printing for TPN Families

10/07/2026 / 6 minutes to read / Tags: 3d-printing, openscad, personal, healthcare

Some projects aren’t about automation, infrastructure, or clever scripts. Some are just about helping people you care about.

Three Small Prints is one of those. It’s a collection of 3D-printed aids designed for families managing children with short gut syndrome on Total Parenteral Nutrition (TPN) therapy.

The Context

Short gut syndrome means the intestine can’t absorb enough nutrients from food. For some kids, that means life depends on TPN — intravenous nutrition delivered through a central line, usually overnight.

Families become clinicians. They spike bags, program pumps, manage tubing, and handle connections with sterile technique. Every night. For years.

The equipment is medical-grade, but it’s not always designed for home use. Small quality-of-life improvements matter when you’re doing something this demanding, this often.

The Prints

Three designs, each solving a specific friction point:

1. S-Hook for IV Pole Management

TPN setups involve a lot of hanging bags and tubing. The S-hook provides a simple way to organize lines, keep connections off the floor, and route tubing cleanly around the bed or pole.

Design considerations:

• Smooth edges (no snagging on tubing)
• Fits standard IV pole diameters
• Easy to clean

2. Weighted Stand for Practice Ampules

Families practice spiking and priming with saline ampules before handling real TPN bags. The weighted stand holds the ampule at a realistic height and angle, making practice sessions feel like the real thing.

Design considerations:

• Stable base (won’t tip during practice)
• Correct height for typical IV pole setup
• Compartment for used ampules

3. Practice Ampule Set

Reusable practice ampules that mimic the feel and connection points of real TPN bags. Lets families build muscle memory without wasting supplies.

Design considerations:

• Accurate connection geometry
• Durable (hundreds of practice cycles)
• Clear visual feedback on connection state

The Tech

I designed these in OpenSCAD — the programmer’s 3D CAD tool. It’s code-driven, parametric, and version-controlled. If you need to adjust a dimension, you change a variable and re-render. No clicking through menus.

// Example: S-hook curvature
hook_radius = 25;  // mm
hook_thickness = 4;
hook_width = 12;

rotate_extrude(angle = 180)
    translate([hook_radius, 0, 0])
        circle(r = hook_thickness);

The STL files are on GitHub, along with the OpenSCAD source. If you need to tweak something for your specific setup, you can.

The Website

I built a simple site for the project: careprints.online

It’s intentionally minimal:

• What the project is
• What each print does
• A request form for families who want the prints

The form originally used mailto: — simple, no backend, just opens your email client. But that’s not great accessibility. Some people don’t have a desktop email client configured. Some are on phones. Some just want to click submit and be done.

So I replaced it with a proper PHP handler:

<?php
// submit.php - validates POST, processes checkboxes, sends email
if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    exit('Method not allowed');
}

// Validate required fields
$name = trim($_POST['name'] ?? '');
$email = filter_var($_POST['email'] ?? '', FILTER_VALIDATE_EMAIL);
$items = $_POST['items'] ?? [];  // Checkbox array

if (!$name || !$email || empty($items)) {
    http_response_code(400);
    exit('Missing required fields');
}

// Send email to [email protected]
// Redirect to success page
?>

The backend runs on my cPanel hosting (voonix.com.au). Nothing fancy — just standard PHP mail handling with proper validation and a success redirect so people know it worked.

Why Open Source?

The designs are on GitHub under an open license. Here’s why:

1. Iterate faster — If someone improves the design, everyone benefits
2. Local printing — Families with access to a 3D printer (or a local library/makerspace) can print on demand
3. No vendor lock-in — If I can’t keep up with demand, others can help

The goal isn’t to build a business. It’s to make sure families who need these can get them.

The Name

“Three Small Prints” is literal — three designs, all small enough to print in a few hours on any consumer printer. But it’s also about the idea that small things, printed in plastic, can make a real difference in someone’s daily life.

Get Them

If you’re a TPN family and want the prints:

1. Request via the site — careprints.online
2. Print them yourself — STL files on GitHub
3. Modify as needed — OpenSCAD source is included

No cost. No strings. Just practical aids for a tough situation.

Links:

• 🖨️ Three Small Prints on GitHub
• 🌐 careprints.online