3D Printed Leg
Adjustable Prosthetic Leg - V2

Another one-size-fits-all 3D printed leg.

Ethan Shute, Incept 3D

Description

A stronger, sleeker, and more functional version of our 3D printed prosthetic leg.

Introduction

A few months ago, we designed a fully adjustable 3D printed prosthetic leg meant to accommodate any size. After getting some feedback, we’re excited to immediately introduce version two. Let’s get into it.

To significantly increase the strength, we swapped out our plastic core with a massive, steel screw. Also, our aesthetically redesigned shin is now printed from a carbon fiber nylon blend.

Next, let’s move up the leg, to the socket of the prosthesis. Using TPU diamond-slotted flaps laced with a specialized cable and micro-adjustment dial system, you can easily and evenly fit and form the connection to any size or shape with a comfortable and secure attachment.

And finally, let’s move all the way down to our revamped, dynamically responsive feet. With this new, sporty design, we made sure you can easily swap them out with a different size or density anytime.

3D Printed Leg
3D Printed Leg

Problem Statement

After initial testing, we quickly realized that Version 1 was far too large, fitting only adults. The primary goal of the leg is to grow with the user, as children often outgrow their prosthetics in just a few months. We missed the mark on that, and while we were developing a smaller version, we took the opportunity to give it a complete redesign.

Project Goal

A full redesign that’s stronger, sleeker, more functional, and modular enough to fit any size.

Team Members

  • Ethan Shute – Designer, Fabricator, and Hand Model

Files and Videos

To access the files for this project, check out our models on Makerworld:

Leg Prosthetic - Child (Makerworld)

Leg Prosthetic - Junior (Makerworld)

Leg Prosthetic - Adult (Makerworld)

⚠️ Disclaimer

If you want to build this yourself: This prosthetic leg design is an experimental prototype and is provided as-is for educational and developmental purposes only. It is not certified, approved, or tested for clinical, medical, or long-term use.

Build Guide

IMPORTANT! Please read before starting:

  1. Each leg comes with multiple different sized feet to accommodate different foot sizes. Under "Download STL/CAD Files" in the Makerworld dropdown, we have provided a 3mf for sizes 3, 5, 7, 9, and 11 called TPU Feet Sizes 3-11. Please print the size that works best for you!

  2. This project requires different materials for different applications within the prosthetic. In order to print this project properly and safely, please print the right files with the right materials, referencing the Slicer Settings in the below Build Guide or the names of the .3mf files in Makerworld.

To begin, choose your size. While there are no strict size guidelines and every foot size fits on every size of leg, we found the general guidelines to work well for us:

  • Child: 4-12 years old

  • Junior: 13-17 years old

  • Adult: 18+ years old

Child
Junior
Adult

Bill of Materials

DoneQtyPartDimensions
1High-Strength 10.9 Steel Hex ScrewM14 × 2mm Thread · 50mm Length
118-8 Stainless Steel Key Locking InsertM14 × 2mm Thread · 20mm Install Length
12Heat Set Inserts for PlasticM3 × 0.5mm Thread · 3.8mm Install Length
4Heat Set Inserts for PlasticM4 × 0.7mm Thread · 4.7mm Install Length
4Socket Head Hex ScrewsM3 × 0.5mm Thread · 5mm Long
6Button Head Hex ScrewsM3 × 0.5mm Thread · 6mm Long
6Button Head Hex ScrewsM3 × 0.5mm Thread · 12mm Long
8Socket Head Hex ScrewsM3 × 0.5mm Thread · 25mm Long
12Hex NutsM3 × 0.5mm Thread
4Socket Head Hex ScrewsM4 × 0.7mm Thread · 16mm Long
4Button Head Hex ScrewsM5 × 0.8mm Thread · 40mm Long
2Button Head Hex ScrewsM5 × 0.8mm Thread · 50mm Long
6Hex NutsM5 × 0.8mm Thread
1Velcro Strap47cm Length
1Micro Adj Dial Cable System1.2mm Diameter Cables
1EVA Foam w/ Adhesive Backing¼″ Thickness · 1 SQ/FT

Slicer Settings

PartMaterialInfill / WallsPatternOrientationAdditional Settings
4× TPU Flaps95A TPU20% / 2GyroidFlat side, face upTextured PEI bed, no brim or supports
2× TPU Knee Supports95A TPU20% / 2GyroidFlat on non-fillet faceTextured PEI bed, no brim or supports
2× TPU Thigh Cradle95A TPU20% / 2GyroidUpright, semi-circle facing left/rightTextured PEI bed, no brim or supports
YTH/JR Ankle Block95A TPU60% / 2GyroidThrough holes face downTextured PEI bed, no brim, enforce supports at 45° for overhangs
YTH_CradlePA6-CF20% / 2TrianglesHex hole face downPolymer adhesive on bed, no supports in hex hole, enforce supports at 45° on outer portion, 10mm brim
YTH_Shin_InnerPolymax PC20% / 3TrianglesStanding tall, thick side face downPolymer adhesive, 4× primitive mouse ears on bottom rounded corners, enforce support within bottom opening, 10mm brim
YTH_Shin_OuterPA6-CF20% / 2TrianglesStanding, flat face downPolymer adhesive, 10mm brim, no supports
ERGO_Size-3_Dyna_FootPA6-CF40% / 2GyroidSideways face down, rotated 45° ZPolymer adhesive, enforce tree supports at 45°, 10mm brim
ERGO_Size-3_TPU_Foot-Lft95A TPU20% / 2GyroidFlat side face down, rotated 45° ZTextured bed, no supports or brim, scale to 101.5%, enforce 0.25–0.25 Voronoi fuzzy skin on bottom sole
ERGO_Size-3_TPU_Foot-Rht95A TPU20% / 2GyroidFlat side face down, rotated 45° ZTextured bed, no supports or brim, scale to 101.5%, enforce 0.25–0.25 Voronoi fuzzy skin on bottom sole

Assembly Steps

As a final step, you'll need to install the micro-cable adjustment system. This is best explained in video form, as shown below. The video also includes instructions on size adjustment for when your child grows.

Questions or concerns?

Thank you for your interest in our fully adjustable 3D-printed prosthetic leg. We hope the documentation above provides a comprehensive guide that allows you to build this leg yourself. For any further questions or concerns, please provide detailed responses to the questions below.