Introducing the “Knick Finger” • 3D Printed Partial Finger Replacement Device

Recently, while searching the internet for new stories to share here on the blog, I stumbled upon a new design for a single finger that was created by an end user who has taken the “Owen Replacement Finger” to a whole new level and it is GORGEOUS!

In July of 2014, Nick Brookins, media services engineer at Akamai Technologies and tinkerer of “things”, found himself in the hospital with an amputated finger, after a motorcycle accident in the mountains near Sand Diego.

Nick shares, “I’ve always been a tinkerer, so first thought in the hospital was that I could build myself something interesting, as I had heard about 3D printed prosthetics before.

I glanced at available options but wasn’t terribly impressed with it came down to it, especially for those of us missing two knuckles. Buying one? What fun would that be?! The after market devices offered by most doctors were silly silicone contraptions that didn’t move or function.”

While Nick was inspired by the original Owen Replacement Finger design, he created the Knick Finger from scratch using OpenScad code and printed it out on his Printrbot Simple. Being inspired by the e-NABLE Community, he has also released the design into the open source community under a Creative Commons license so that others can create these fingers as well.


“I’d read articles about e-NABLE, which led me to thingiverse where I found the Owen Finger. Getting started was the hardest part and his design gave me something to get off the ground and iterate on as I started grasping all of the necessary concepts. My 1.0 verison was a mashup of that finger with adapted parts from Flexy hand. It was a big milestone because once I had something I could start wearing, I could start thinking of a lot of little improvements,” says Nick.


Version 2.0 took me a couple of months and was a fresh start in Sketchup. It came together pretty well but then I had two problems. It was tough to print and build. As I wanted to keep improving, it was very time consuming to make tweaks and changes and extremely difficult to adapt to different people’s needs.

I fell in love with OpenScad about a year ago, being a coder already, it came naturally. I started on a second ground-up design, with the goal of making something extremely configurable and much easier to build than my previous one. I can now assemble the printed parts into a perfect finger in about 30 minutes!

I am super happy with version 3.5. It’s been easy enough to build that I can build a fun collection of different variations and I’m seeing that others are having more success with building their own. I think my device benefits greatly from me being both the designer and the consumer as I am able to address a lot of the little annoyances that would be hard for a designer that didn’t wear one, to understand.”

For Nick, this 3D printed finger has become a part of his daily life. He shares, “I put it on before I brush my teeth and take it off when I go to bed. It’s generally useful for everyday stuff and it always surprises me how clumsy I am at grasping or holding, without it. I can type on my Macbook and plan to make it work with touch screens in the future.

I find it much more useful than not. I’ll often go through a day and not think once about it until I’m wondering why someone is staring and realize they are just interested. It’s quite a fun conversation starter and people often ask about what they think is some kind of “fancy finger brace” and are surprised to learn it’s a prosthetic.

I have also discovered that it also protects my very sensitive nerve endings. Without it on, a small bump to the finger stump can be very painful.”

Nick goes on to say, “I’d love for this finger to become more widely known and available and will keep making improvements that can make it more useful for more people. For example, I have an acquaintance who needed a thumb so I made it adjustable to have only one knuckle. I also have someone on the waiting with with multiple finger losses, which might need a more advanced wrist linkage. I also want to keep making it easier to configure and build so it is accessible by more people.”

So what do you say?

How about we help get this beautiful design shared throughout the world so that even more people can benefit from Nick’s work?!

If you make one for yourself, someone you know or just for fun – please share images with us by using the hashtags #enablethefuture and #enable on Twitter, Instagram and Facebook! We love to see what you are creating!

You can find the files and instructions for this design HERE.


3 thoughts on “Introducing the “Knick Finger” • 3D Printed Partial Finger Replacement Device

  1. Juan Araiza Reply

    Hi, I am a whip maker from Texas and I use a special filament that is 15 times stronger than steel to make the cracker end of my whips. I noticed your “tendons” look like wire. Well… wire can stretch, it sets off metal detectors, and it is rough which will eventually ruin the surface it is fitted into. The material I use is smooth as silk, is not made of metal and won’t damage plastic surfaces. I recently had an accident and I’m worried I will lose two finger tips as well as losing feeling in those finger tips so I cannot tell if I accidentally touch a hot surface or cut myself, I would love to talk with you and share any information I have compiled so that we could potentially give your finger prosthetic an added strength and make it easier to perform maintenance on. This wonderful material is rather expensive BUT I have a secret source that will help get this moving along if you’d want to mass produce prototypes. I am genuinely trying to help prosthetic designers and not capitalize on people’s misfortune, materials for prototyping will be shared as best as I can provide. Thank you for your time!

    • Jen Owen - e-NABLE Volunteer Post authorReply

      Hello Juan!

      Thank you for your comment!

      Actually, the “Tendons” are made of non braided fishing line so they don’t wear down the holes or cut into the plastic and they do not set off metal detectors. 🙂

      You can reach out to the design community through the Google+ page. Link is in the “Get Involved” tab. 🙂

      Thank you!

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