Summary

Fully Adjustable Prosthetic

A one-size-fits-all 3D printed leg designed for children to pre-teens

A fully adjustable, 3D-printed, lower limb prosthetic to improve long-term outcomes particularly for children and adolescents living with lower limb loss.

Introduction

After getting some feedback on Version 1, we’re excited to introduce Version 2.

To significantly increase the strength, we swapped out our plastic core with a steel thread core. 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.

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

Finally, the leg now comes in three sizes, Child, Junior, and Young Adult. Each of which can have the height adjusted, with the goal of accommodating any size from small children to tall adults.

Important Notes

Please note that this thingiverse file comes with multiple different sized feet to accommodate different foot sizes. We have provided files for sizes 5, 7, and 9. Please print the size that works best for you! If you need sizes bigger than this, please visit the Child size leg or Young Adult sized leg for additional sizes.

Additionally, if this leg appears to be either too short or too long, please feel free to look at and print either the Child Version or Young Adult to fit your needs.

Bill of Materials

🔢 Qty	🔩 Hardware Part	📐 Dimensions
1	HIGH-STRENGTH 10.9 STEEL HEX SCREW	M16 x 2mm thread, 150mm length
1	18-8 STAINLESS STEEL KEY LOCKING INSERT	M16 x 2mm thread, 22mm install length
12	HEAT SET INSERTS FOR PLASTIC	M3 x 0.5mm thread, 3.8mm install length
7	HEAT SET INSERTS FOR PLASTIC	M4 x 0.7mm thread, 4.7mm install length
1	HEAT SET INSERTS FOR PLASTIC	M5 x 0.8mm thread, 6.7mm install length
12	BUTTON HEAD HEX SCREWS	M3 x 0.5mm thread, 6mm long
8	SOCKET HEAD HEX SCREWS	M3 x 0.5mm thread, 25mm long
8	HEX NUTS	M3 x 0.5mm thread
2	SOCKET HEAD HEX SCREWS	M4 x 0.7mm thread, 12mm long
4	SOCKET HEAD HEX SCREWS	M4 x 0.7mm thread, 16mm long
1	SOCKET HEAD HEX SCREW	M4 x 0.7mm thread, 18mm long
4	BUTTON HEAD HEX SCREWS	M5 x 0.8mm thread, 40mm long
2	BUTTON HEAD HEX SCREWS	M5 x 0.8mm thread, 50mm long
1	GRUB SCREW	M5 x 0.8mm thread, 12mm length
6	HEX NUTS	M5 x 0.8mm thread
2	MICRO ADJ DIAL CABLE SYSTEM	1.2mm diameter cables
1	EVA FOAM W/ ADHESIVE BACKING	1/4" thickness, 1 sq/ft

Slicing and Printing

Material choice, Infill patterns, and densities are crucial for optimizing the prosthetic's strength and flexibility. While you do not have to follow these instructions exactly when slicing at home, these are the recommended materials, orientations, and slicing instructions that we used here at Incept 3D.

Step by Step Assembly

Step 1

Heat and Install M16 key lock thread insert to Jr_Shin_inner.
Use M16x2mm-150mm long to install threaded insert to Jr_Shin_inner.

Step 2

Add 2-part plastic welder or epoxy to the hex well of Jr_Adjustment_Dial.
Pass High Strength 10.9 Steel Hex Screw through Jr_Adjustment_Dial and keep in place until the adhesive is cured.

Step 3

Install 7x_M4x0.7mm-4.7mm long heat set inserts to the 3 top outside holes and the 4 top holes of Jr_Shin_Main.

Install one M5x0.8mm 6.7 long heat set insert to the back hole of Jr_Shin_Main.

Step 4

Feed Jr_Adjustment_Dial with adhered bolt through the top of Jr_Shin_Main and feed the Jr_Shin_Inner through the bottom.
Turn the Dial clockwise to secure the Jr_Shin_Inner to the bolt.

Step 5

Install 12x_M3x0.5mm-3.8mm long heat set inserts to the Jr_Upr_Leg_Cradle on the holes on the top rim.

Step 6

Secure the top Jr_Uper_Leg_Cradle with 4x_M416 socket head hex screws.
Secure the the rear of Jr_Uper_Leg_Cradle with one M4x28 socket head hex screw.
Secure sides of Jr_Uper_Leg_Cradle with 2x M4x12 socket head hex screws

Step 7

Install 2x Jr_Flap_Holder-1 to the front (Where the dial is visible) and back of Jr_Uper_Leg_Cradle with 6x_M3x6 button head hex screws.

Step 8

Install 2x Jr_Flap_Holder-1 to the sides of Jr_Uper_Leg_Cradle with 6x_M3x6 button head hex screws.

Step 9

Install 4x_M5x40mm button head hex screws to the Dyna_Foot with the desired Foot Size. Secure the Dyna_Foot to the Ankle_Block using M5 hex nuts.

Step 10

Install 8x_M3x25mm socket head hex screws to the TPU_Foot_LFT of the desired foot size and secure the two halves together over the Dyna_Foot using 8x_M3 hex nuts.

Step 11

Install the Jr_Shin_Inner to the Jr_Ankle_Block with 2x_M5x50 button head hex screws and secure through the back with 2x_M5 hex nuts

Complete!

If you have any questions about any part of this build, please let us know. We'll do our best to answer any questions.

UPDATE

Based on feedback we've received from people we've sent legs to, we've added Knee_Support and Thigh_Cradle. For detailed instructions on how to install, please see the video linked below or our Child version of this print!

Additional Post Printing Details

Foam Backing

While these are wearable on their own, we recommend using adhesive backed foam listed in the Bill of Materials on the back of the TPU_Flaps and Knee_Support for comfort and a velcro strap to secure the Knee_Support

Lacing, Getting In and Out of your Prosthetic, and Lengthening and Shortening

For a video tutorial on how to properly lace up your prosthetic leg, getting in and out, and to lengthen and shorten your leg, please see here:

Fully Adjustable Prosthetic V2 - Junior

Fully Adjustable Prosthetic