Summary

Fully Adjustable Prosthetic

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

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 7, 9, and 11. Please print the size that works best for you! If you need sizes smaller than this, please visit the Junior size leg or Young Adult sized leg for additional sizes.

Additionally, if this leg is too tall for your needs, we also have a Child and Junior prosthetics in our profile. Please feel free to take a look and see if those fit your needs better!

Bill of Materials

🔢 Qty	🔩 Hardware Part	📐 Dimensions
1	HIGH-STRENGTH 10.9 STEEL HEX SCREW	M16 x 2mm thread, 180mm 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	M5 x 0.8mm thread, 6.7mm install length
1	HEAT SET INSERTS FOR PLASTIC	M6 x 1mm thread, 7.6mm install length
12	BUTTON HEAD HEX SCREWS	M3 x 0.5mm thread, 6mm long
8	SOCKET HEAD HEX SCREWS	M3 x 0.5mm thread, 45mm long
8	HEX NUTS	M3 x 0.5mm thread
2	SOCKET HEAD HEX SCREWS	M5 x 0.8mm thread, 8mm long
4	SOCKET HEAD HEX SCREWS	M5 x 0.8mm thread, 20mm long
1	SOCKET HEAD HEX SCREW	M5 x 0.8mm thread, 16mm long
4	BUTTON HEAD HEX SCREWS	M5 x 0.8mm thread, 50mm long
2	BUTTON HEAD HEX SCREWS	M5 x 0.8mm thread, 55mm long
1	GRUB SCREW	M6 x 1mm thread, 10mm 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 threaded insert to Sr_Shin_Inner using 180mm hex screw.

Step 2

Add 2-part plastic welder or 2-part epoxy to hex socket well in Sr_Adjustment_Dial.
Pass 180mm hex screw through top of Sr_Adjustment_Dial and seat within socket until cured

Step 3

Install 7x_M5x0.8mm-6.7mm long heat set inserts to the top and side of Sr_Shin_Main as shown.

Install 1x_M6x1mm-7,6mm long heat set insert to the back side of Sr_Shin_Main as shown.

Step 4

Feed the Sr_Adjustment_Dial with glued bolt through the top of Sr_Shin_Main.

Secure Sr_Shin_Inner by feeding through the bottom of Sr_Shin_Main and screwing the Sr_Adjustment_Dial clockwise and tighten until secure.

Step 5

Install 12x_M3x0.5mm-3.8 long heat set inserts to the upper perimeter of Sr_Uper_Leg_Cradle as shown.

Step 6

Secure the Sr_Upr_Leg_Cradle to Sr_Shin_Main by installing 4x_M5x20mm socket head hex screws through the top of Sr_Upr_Leg_Cradle.

Install 1x_M516 socket head hex screw on the rear of Sr_Upr_Leg_Cradle

Install 2x_M5x8mm socket head hex screws on each side of Sr_Uper_Leg_Cradle.

Step 7

Install 2 of the Sr_TPU_Flaps to the Sr_Upr_Leg_Cradle by installing 6x_M3x6 button head hex screws to the bottom portion of the Sr_TPU_Flaps as shown.

Step 8

Repeat Step 7 with the other 2 Sr_TPU_Flaps on the sides of Sr_Upr_Leg_Cradle as shown.

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 and secure the two halves together over the Dyna_Foot using 8x_M3 hex nuts.

Step 11

Install Sr_Shin_Inner to Ankle_Block by using 2x_M5x55mm button head hex screws through the front as shown and secure with 2x_M5 hex nuts in the back.

Complete!

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 - Adult

Fully Adjustable Prosthetic