# Specific 3D Printing Applications / Fields / Conferences > 3D Printing Prostheses & Robotic Limbs > Individual Robotic Limb / Prosthetic Projects >  Flexy-Hand

## Gyrobot

Greetings all,

The Flexy-Hand - A proof of concept printable hand with "live hinge" flexible joints. Individually activated fingers using Filaflex filament as tendons (Alternatively use Nylon fishing wire) :




Printed in Makerbot Translucent Red and Filaflex hinges.     Re-mix this idea into your own robotic or prosthetic project.   


Fingers open automatically, no return tendons or springs needed."Frictionless" articulation - no rubbing parts.Stretchable tendons offering adaptive grip on irregular objects (only one motor required to activate all fingers).Fully printable solution, no vitamins required.Tough and rugged.Realistic form under a surgical glove. 




http://www.thingiverse.com/thing:242639

Thank you for reading.
Steve Wood (AKA Gyrobot)
w: http://www.gyrobot.co.uk
f: http://www.facebook.com/gyrobotuk
tw: @gyrobotuk

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## Davo

That looks really well done, Steve.

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## intohim

That's truly awesome!  Did you guys come up with this idea from scratch or is it a remix of another project?

Also, how do the tendons work if someone were to use this as a prosthetic?  How would a person bend their fingers using these tendons if they were missing a hand?

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## Gyrobot

I am into flexible filament printing at the moment and this was my idea for 3D printing combination of materials, to give interesting results. This could be printed with a dual extruder machine, with each material being printed with each extruder.

The idea wasn't to offer a direct prosthetic, just to sow the seed of thought into those developers out there who are more specialised in this field. Having said that the hinged figers could be a direct replacement on  the Robohand project, using nylon fishing wire as the tendons instead.

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## Eddie

I love this.  This is a dream prosthetic for the right person.  Did you get my PM Gyrobot?  
Ed

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## Jeeplvr

Nice work! The range of motion is very short but could be extended with a little modification. The thumb should be able to touch the index finger at the very least. Range of motion is definitely one of the challenges when making prosthetics. Also getting the segments to move fluidly with little effort is another challenge. When I saw this I immediatly pictured a set of small servos pulling each tendon.  :Smile:

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## pardonme

> Also, how do the tendons work if someone were to use this as a prosthetic?  How would a person bend their fingers using these tendons if they were missing a hand?


I'm also curious as to how someone missing a hand could integrate the tendons into their arm so that when they want to close one finger, it will do so.  Would it need some sort of motor?  I'm not familiar with how traditional prosthetics work.  Is there a way to use the electrical impulses from the brain to make the tendons react?

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## Gyrobot

> Nice work! The range of motion is very short but could be extended with a little modification. The thumb should be able to touch the index finger at the very least. Range of motion is definitely one of the challenges when making prosthetics. Also getting the segments to move fluidly with little effort is another challenge. When I saw this I immediatly pictured a set of small servos pulling each tendon.


Trust me, the thumb and index finger do touch, tomorrow I will upload pictures of this pose.

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## Gyrobot

> Nice work! The range of motion is very short but could be extended with a little modification. The thumb should be able to touch the index finger at the very least. Range of motion is definitely one of the challenges when making prosthetics. Also getting the segments to move fluidly with little effort is another challenge. When I saw this I immediatly pictured a set of small servos pulling each tendon.


Here are some images showing the thumb touching the first two fingers, and close to the ring finger.

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## Eddie

Thanks for showing these.  This should clear some things up  :Smile: 

BTW, we just published an article on the Flexy-Hand!

The Flexy-Hand, The Most Innovative, Useful, Realistic Looking 3D Printed Prosthetic Hand Yet http://3dprint.com/1500/the-flexy-ha...ed-prosthetic/

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## ToyMakerRon

Man, this is truly revolutionary in my opinion.  This is the most realistic looking hand I've seen yet from the 3D printing community.  Awesome job Gyrobot!

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## Gyrobot

> Man, this is truly revolutionary in my opinion.  This is the most realistic looking hand I've seen yet from the 3D printing community.  Awesome job Gyrobot!


Thank you, except that it is bright cherry red, not too realistic hahahaha.

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## Nestegg

Love the hand! I will print one myself and get back to you. But at the moment it looks like something Id like to use for a couple of projects.

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## Luv2Fight

> Love the hand! I will print one myself and get back to you. But at the moment it looks like something Id like to use for a couple of projects.


What type of projects?  I'm just curious.  I mean what can you use a robotic hand for other than a robot or a prosthetic?

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## Nestegg

> What type of projects?  I'm just curious.  I mean what can you use a robotic hand for other than a robot or a prosthetic?


Yeah, a prosthesis I'm working with a team to design.

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## Rainday21

> Yeah, a prosthesis I'm working with a team to design.


You will definitely have to show us your results!

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## Gyrobot

I made another one : http://www.thingiverse.com/make:69561

Notice the "adaptive grip" :

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## RimReaping

Looking good.  Keep those updates coming!  I'm loving the adaptive grip.  Any news on anyone using one of these yet as a prosthetic?

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## Gyrobot

> Looking good.  Keep those updates coming!  I'm loving the adaptive grip.  Any news on anyone using one of these yet as a prosthetic?


I know the Open Hand project in Bristol, UK have ordered some Filaflex to have a play around with, so there may be a possible route there.

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## Jeeplvr

Great work, I am looking forward to seeing these hands help those in need.

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## Gyrobot

I have uploaded a two part mould that you can print off and inject flexible sealant (silicon etc) into to make your own hinges. I have included the stl file in the original Flexy-Hand repository and also uploaded as it's own thing here

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## UPSdan

one thing i havent seen lately was the use of bicycle brake lines. They don't need to be held under tension like the current model

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## Gyrobot

I have uploaded a slightly modified thumb position (original in green below) , which is more opposable to the index and middle finger for better crushing ability ROOOAAARRRR! A right hand version of this was also uploaded.

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## Gyrobot

Flexy-Hand 2 is now available to download and print as a wearable prosthetic :

http://www.thingiverse.com/thing:380665

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## JRDM

That is such a terrific improvement. I was disheartened when so many artificial hand projects lately were still block-hands.

I get that people want to help, but sometimes it helps to have experienced CAD operators, part modellers and such, because box-hands in 2014 is sad.

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## Gyrobot

The original Flexy-Hand has been integrated into a myoelectric arm :

http://enablingthefuture.org/2014/07...oelectric-arm/

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## Gyrobot

Here is a some pictures and video of a Black Flexy-Hand 2 :

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## Gyrobot

Some pictures of the latest Flexy-Hand 2 - Filaflex Remix

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## GeoStringer

I'm interested in prosthetics, but haven't purchased a printer yet.   I had the same ideas you did on the servos to make it work just like a real hand.

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## Christina Jackson

You did this? This is so awesome! Great work!

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## Shift Koncepts

I just bought a Mark forged 3d printer that can print nylon, fiberglass, kevlar and carbon fiber.  Would it have a significant impact on the current prosthetic models?

Thanks,

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## mcbb

I'm seriously considering using the flexy-hand as the basis of the design for a robotic hand, using servos to move each finger individually. Anyone have any suggestions or ideas?

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## arezendes

Thanks for sharing this @Gyrobot . I too am creating a black version of the Flexi-Hand on my Prusa i3 Mk3. 
I've got all the fingers attached, cables (fishing line) ready to connect to the tensioners, and wanted to pick your brain about 2 things: Tensioner Adjustments and Grip Strength.

1) It appears that you've tied off your lines to the tensioners and they're at different heights. Is that so that you can accommodate the finger range? Looks like you've also got some screw hardware on the back part of the arm brace. What size and type are you using? From the brace, I printed out it looks like maybe a #6 or #8 woodscrew because they are countersunk, but thought you'd know what works best.

2) So far as grip goes, how strong is it? Can you pick up things like coffee mugs and soda cans, or is it not strong enough for that? Can you adjust grip strength through the tensioners or you always going to be beholden to the angle the wrist can bend at the joint?

Thanks in advance for your time.
arezendes




> The original Flexy-Hand has been integrated into a myoelectric arm :
> 
> http://enablingthefuture.org/2014/07...oelectric-arm/

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## Fisher

The topic's a long time ago, you probably won't get an answer...

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## EdwardVicknair

The Original Prusa i3 MK3S is our pick for the "Best 3D Printer in June 2020 :Embarrassment:

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