# Specific 3D Printing Applications / Fields / Conferences > 3D Printing Prostheses & Robotic Limbs >  The Wounded Soldier Raptor Prosthetic Hand

## Eddie

You may recall a man named Aaron Brown.  He had created the 3D Printed Prosthetic Wolverine hand for children.  Now he is at it again with a hand he called the "Wounded Soldier Hand".  It is targeted toward active adults and specifically veteran of war who have lost a limb.  The Wounded Soldier Hand features the ability to add on accessories and tools such as a flashlight, toothbrush, utility knife, and more.  The possibilities are endless with the special track system that the hand uses.  Read and see more on this at: 
http://3dprint.com/16976/wounded-solder-prosthetic/

----------


## Geoff

I wonder if they could use kevlar or some other materials for the strings, it's about the only weak point in looking at that pic, I think once they use a good material for that you could even see a normal gauntlet for people who still have limbs, and have them being used in a more offensive manner, like suits of armour etc. 

Has anyone mixed kevlar with 3d printing yet? possible?

----------


## old man emu

Kevlar does not melt. It is a solid up to about 450C, then it decomposes.

Ref: http://www2.dupont.com/Kevlar/en_US/...ical_Guide.pdf

OME

----------


## AxisLab

> I wonder if they could use kevlar or some other materials for the strings, it's about the only weak point in looking at that pic, I think once they use a good material for that you could even see a normal gauntlet for people who still have limbs, and have them being used in a more offensive manner, like suits of armour etc. 
> 
> Has anyone mixed kevlar with 3d printing yet? possible?



There are a number of options for the tendon lines, nylon, fishing line, steel and even titanium braid wire. For the most part these hands are for simple daily tasks. and give a grip strength of around 20-25 pounds. 
The main point, being the design it is, the strength is dependent on the users wrist. all power comes from bending the wrist itself, so no matter how strong you make the tendon lines, you still are only going to be pulling the fingers at the same level of power anyway, so no real reason to go overboard.

One benefit of using stronger lines, is however, the reduction is stretch. Cord and nylon, after weeks of use will gat a small amount of memory stretch in them, and need to be tightened a bit. Easy enough to do with a few twists of the 5 screws on the back, but stronger lines do eliminate that need.

----------


## Geoff

> There are a number of options for the tendon lines, nylon, fishing line, steel and even titanium braid wire. For the most part these hands are for simple daily tasks. and give a grip strength of around 20-25 pounds. 
> The main point, being the design it is, the strength is dependent on the users wrist. all power comes from bending the wrist itself, so no matter how strong you make the tendon lines, you still are only going to be pulling the fingers at the same level of power anyway, so no real reason to go overboard.
> 
> One benefit of using stronger lines, is however, the reduction is stretch. Cord and nylon, after weeks of use will gat a small amount of memory stretch in them, and need to be tightened a bit. Easy enough to do with a few twists of the 5 screws on the back, but stronger lines do eliminate that need.


Fair enough, I guess you want them to also be fairly adjustable and easily adjustable also.

It's pretty amazing isnt it, you can get a 3D printer, a mindwave bio kit, an arduino... some servos and now someone at home can make their own mind controlled bionic hand.. man who would have thought..

----------


## Compro01

> I wonder if they could use kevlar or some other materials for the strings


Probably.  Kevlar thread and cord is pretty readily available (search on Amazon.  Lots of results.  Not very expensive either.), though as Axislab notes, it's vicious overkill in terms of strength.

----------


## Geoff

I am just thinking something that is a little more fireproof, I would imagine a small blast going off nearby might produce enough residual heat to melt the cords, so if they were some sort of carbon based wire, or something more fire and damage resistant. Im just trying to think how you could make them less susceptible to damage. I am not sure how often these need adjusting, would it not be possible to cover all the wiring with a plate? or would it be a pain to keep taking off?

----------


## AxisLab

> I am just thinking something that is a little more fireproof, I would imagine a small blast going off nearby might produce enough residual heat to melt the cords, so if they were some sort of carbon based wire, or something more fire and damage resistant. Im just trying to think how you could make them less susceptible to damage. I am not sure how often these need adjusting, would it not be possible to cover all the wiring with a plate? or would it be a pain to keep taking off?



These are not meant for active duty, these are prosthetic hands, intended to simply help get a wounded soldier back the access to some daily tasks. Cutting your own food, or picking up simple objects.
If someone is working around "small blasts" or needs a protective plate, I'm thinking they would want a hand built of something more that plastic velcroed to their hand.

These are in no way intended for any dangerous work. Simply a low cost alternative that is available instead of the high end prosthetics with long waiting lists.

----------


## Geoff

> These are not meant for active duty, these are prosthetic hands, intended to simply help get a wounded soldier back the access to some daily tasks. Cutting your own food, or picking up simple objects.
> If someone is working around "small blasts" or needs a protective plate, I'm thinking they would want a hand built of something more that plastic velcroed to their hand.
> 
> These are in no way intended for any dangerous work. Simply a low cost alternative that is available instead of the high end prosthetics with long waiting lists.


Sorry,  :Stick Out Tongue:  I read it wrong, I thought it was for use in the battlefield, rather than long after.

----------


## docdavies

Would someone be so kind as to direct me to the files for this hand?

I've got a VA group in my area that's interested and I wanted to make a few demo hands for them to examine.

Thanks,
Doc

----------


## SarahA

> Would someone be so kind as to direct me to the files for this hand?
> 
> I've got a VA group in my area that's interested and I wanted to make a few demo hands for them to examine.
> 
> Thanks,
> Doc


Hi Doc! The original article notes that this design was based on e-NABLE's latest version of their Raptor hand, so it looks like the Raptor Reloaded would be your best bet. From there, this particular design was customized. There are some specifics to how it was customized -- with the Picatinny rail system -- in the original article here, so there are tons of options for getting it exactly to your desired specifications.

I hope any of that helps! You can also get in touch with e-NABLE for any more specific questions; I'd start with their FAQ to see if they address any particular questions you might have to get started. These hands would be amazing for vets, and I hope that VA group is interested. I've met some really amazing people involved with the VA and some who just don't care. These vets need more people who care and are willing to step up and help out. Kudos, and good luck!

----------

