# Specific 3D Printing Applications / Fields / Conferences > 3D Printing Prostheses & Robotic Limbs >  Extension assist glove

## mushroombrew

I noticed that this is in the wrong forum and don't know how to delete or move it.  If admin, please feel free to remove it from here.  Sorry..    


I've got Charcot Marie Tooth disease.  If you're not familiar with that, It's a hereditary neuromuscular condition that causes muscles in your extremities to atrophy.  Particularly in the hands and feet.  I wear Allard Toe-Off braces on my legs for foot drop and they have changed my life.  My hands are still a problem though.  My fingers want to curl up into a fist and I can't straighten them without touching them with my other hand.  That limits me in a great many ways and I have had to get creative.  This entire message was typed with my two thumbs for instance since I can't even hunt and peck with my index fingers anymore.  Typing by touch was never an option even when I was young.  I do have a decent enough grip however.  I'm lucky enough to still be able to work, but it would be AMAZING if there were a device that would help me open my hands and straighten my fingers.  Something like an articulated glove that I could wear that had some sort of "spring assist" in the joints to give me a little bit of help.  Perhaps leaf or torsion springs.  Maybe even rubber hands.  I don't know.  I recently got a 3d printer and it got me thinking.  I see that there is a community of people working on stuff like this so I thought I'd ask if someone might be interested in looking into it.  I don't have any 3d modeling talent beyond the most basic of designs.  Medical devices are just so expensive too...  To be able to order some parts, print and assemble what I need.  Wow..  Anyway, that's it.  Thanks for reading.  Feel free to ask any questions that you may have.

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## fred_dot_u

There is an organization for which there is a web site:

https://limbitless-solutions.org/

I was lucky enough to attend a presentation at our local library by this group. The web site indicates that the efforts are for children, but I suspect that they may be able to assist you, even if it is only to point you in the right direction for additional resources. 

If you find aspects of the project you are undertaking to be problematic, be sure to post your questions here, as I follow this forum and enjoy assisting when I can. I frequently wish I had more design skills, in order to develop models of this nature. My skill set is but a drop in the ocean of 3D printing design.

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## mushroombrew

Thank you for the reply.  They're doing some very advanced work.  That's awesome.  We live in an exciting time.

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## curious aardvark

where do you live ? 
I can think of a number of ways to do this.
But, as with all things customised it's bloody difficult without the person's limbs in attendance :-)

Something as simple as a basic exo skeletal 'glove' with elastic bands, would probably work. And the beauty of elastic bands is that you can easily adjust tension and they are dirt cheap and simple to change or replace.  

what 3d printer do you have ? 

And have you got someone to do any fine fitting or toolwork when making the 'gloves' ?

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## airscapes

check out the airy arm and the frog arm

https://www.thingiverse.com/thing:2409748
https://www.thingiverse.com/thing:2894781
https://enablingthefuture.org/2019/0...lingthefuture/
Thingyverse is having time out issue atm

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## mushroombrew

I have a Creality CR-10 v2 and a Qidi X-one2 and I live in Cleveland, Tennessee.  I have a E3D V6 hot end that I need to install on the CR-10 v2 along with a steel nozzle.  After that upgrade I'll be able to print in carbon fiber fill and polycarbonate.  I would probably be able to do any fab work myself.  I have a reasonably equipped workshop and my wife gladly joins in whenever I don't have the dexterity to complete a task.  My condition isn't so bad that I have lost functionality completely, but I see the muscles in my hand tightening more and more each year and it has me somewhat concerned. Fiddly tasks can be unbelievably frustrating.  Let me tell you how embarrassing a handshake can be when your fingers curl up inside the other person's hand.  smh...  I can certainly see how designing something like that would be difficult without having the patient present though.  If it would help, I can take very detailed measurements of my hands with calipers.  I've been watching some tutorial videos on Blender but oh boy is it complicated.  I have made a few simple things with tinkercad, but it lacks the functionality that I would wind up needing to make something like this (Or maybe I just lack the talent).  I've included an image of my hand to better illustrate what's going on.  That's as open as I can get it without stretching it repeatedly.  It' resume that shape as soon as I let go.  Other than that and the atrophied appearance, it's fairly average in all regards.  A lot ofpeople ask if I have rheumatoid arthritis since my knuckles appear swollen.  I don't.  No arthritis of any kind.  Hopefully it'll stay that way.

20200218_203203.jpg

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## mushroombrew

Those are some interesting concepts.  I love thingiverse but yeah it has been pretty sluggish as of late.  I may wind up making one of those or at least a part of one.

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## curious aardvark

well what I was thinking was a leather base, with the exoskeleton attached. 

The easy way to go would be to find some cheap, thin leather gloves and attach the elasticated exoskeleton fingers to the backs of the fingers. 
Yeah it'd look weird. 
But it would be pretty easy to do and and you don't need to go into the whole prosthetic limb aspect. 
Just sprung 'joints' along the bacl of the glove fingers. 
If you cut the tips of the glove fingers off - then you have fingertip feeling. 

Kinda like the 'fingerless' gloves I'm wearing now (it's bloody cold in my workshop this time of year). But longer as you want them to extend most of the way along the final section of the finger. So cutting the tips from normal gloves is a much simpler option. 

The exoskeleton could simply be stitched or glued to the back of the glove fingers. 

Also makes it dead simple to put on and take off - although on reflection, how easily can you put on gloves ? 
You could also apply the same principle to any kind of glove. garden gloves, dog walking gloves etc

Have a look at openscad - I find it much much easier to work with than all the gui based 'drawing' cad programs. 

It works purely on you telling it what to draw and where.

A lot of it depends on how your brain works - if you visualise things in 3d but can't draw in 2d (like me) it's soooo much easier to use than a wysiwig based cad package.

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## mushroombrew

The gloves are a good idea.  I'm not really concerned if it looks weird.  I just figure that if I can stand to keep them on for 4-6 hours a day or even while I sleep then maybe the tendons in my hands will relax a bit and restore some dexterity.  Thin leather gloves would be fine, but I wanted to throw this out there since you mentioned it:  I can get as many pairs of these gloves (see image) as I would ever need for free.  We call them "kevlars" since they are cut resistant, but I somewhat doubt that they actually have any kevlar in them.  Somewhat stretchy and they have a rubberized underside for better grip.  Think that might work?  As you suspected, some especially tight gloves are almost impossible for me to get on, but I have to wear the "kevlars" just about every day at work anyway, so they're fine.  I'm going to have a look at openscad.  The concept of rapid prototyping is extremely exciting to me and I feel as if I am missing out by not being able to actually engineer anythingI'm just curious, but what country do you live in?  You said it's "bloody cold" and that has me thinking UK even though they're not the only ones that use that expression.  :/  Back in the '90s I watched a British TV show called "The Secret Life of Machines" by Tim Hunkin and Rex Garrod.  Still one of my favorites.  (And upon looking up Rex to make sure I spelled his name right, I found out that he passed last year.  That really sucks.  He seemed like a very cool guy.)

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## mushroombrew

And I forgot to include an image of the glove.

20200219_163647.jpg

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## curious aardvark

gloves should work fine. 
The important thing would be that you need to be able to stitch them with strong yarn of some kind and they don't easily tear. 

Yep I live smack bang in the geographical centre of england. 
it's currently 16c in my workshop  - 61 weird fahrenheits_ (you know that in that system 100f is based on the temperature of mrs fahrenheits armpits ? Strange but true)


_Now I could warm it up. But it means the water for cooling my k40 laser, stays at the right temperature without my having to bugger about with putting freezer blocks in the bucket :-)

Drop me a pm and we can exchange emails. 

Have you ever printed with flexible pla ?

Anyway I'm off to warm up and eat something :-)
Catch you tomorrow.

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## mushroombrew

Ah, very cool.  I've always wanted to visit there.  Greetings from across the pond.  I'm one rare American that prefers metric over imperial.  I can definitely see an armpit hitting 100 degrees Frankenstein on a balmy summer afternoon though. lol.  I for one prefer it a little cold.  My wife however..  Hmm..  My shop is in the basement though so it stays a little chilly in there all year.By flexible PLA do you mean something like a PLA+ that has more flexibility than regular PLA?  If so then yes.  My favorite is eSun PLA+.  I haven't yet tried anything with TPU though.  The CR-10 V2 uses a bowden extruder so I'm not sure how well it would work with it.  The Qidi uses a direct extruder and the manufacturer claims that it'll run TPU, but I have as yet not been able to verify that.

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## curious aardvark

yeah I'd go for the qidi. 
Flaxible pla is a flexible material made from pla. 
I have no idea how it's amde but it is hands down the toughest material I've ever printed with. 

Tpu = thermoplastic polyurethane - basically synthetic rubber. 
It's usually a bit too floppy to be uch use and the elasticity makes it trickt to print with. 

Unfortunately most retailers now seem to call ALL flexible filaments 'TPU'.  So it's getting kind of hard to tell which are pla and which aren't :-( 

flexible pla is similiar, but tougher, less elastic and usually a bit stiffer. 
This means you can make fairly rigig things from it that are virtually indestructible. Short of using power tools - you just can't damage it.

It means you can make things with lifetime hinges :-)

We can probably get away with tpu. It's just finding one that's a bit stiffer than the others. 
I suppose I'll have to try and figure out how thie bizarre shore hardness acale works.

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## airscapes

Nijatech sells Cheetah which is TPU with a shore hardness of 95.  This is some tough stuff.  I have made faucet washers out of it and it is working better than the soft ones you buy in the hardware store.  I have also make a USB microscope cover ring to use when inspecting knife blades during sharpening, so far no cuts..  The cheetah is also easy to print, sticks to anything like cement but is on the pricey side.  Also not really good if you need support for the model.  Being a US based product not sure of availability in England.  As far as elasticity goes, much less than Ninjaflex..  Details on their products can be found here https://ninjatek.com/

Mushroombrew, I am located in the Philadelphia PA area if you happen to be near by please let me know as I have contacts at the Enabling the future Chapter at the Drexel University bio engineering lab who I am sure would be interested in assisting.  If not near by, I wish you lots of luck on your collaboration and  project and please let me know if I can help in any way.

Doug

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## mushroombrew

I had no idea that actual flexible PLA was a thing.  I watched a few videos about it on youtube.  They even manage to get it to work with a bowden extruder much like my own.  I'm going to get some either way.  Lots of potential with something like that.  @Airscapes  Thank you for the input.  I have heard how stretchy some of the Ninjaflex stuff is but I've never heard of Cheetah.  I'm going to look into that filament too.  Price isn't too big of a deal (within reason of course).  I live in Cleveland, Tennessee.  Close to the TN/NC border.  It's east of the Mississippi at least. :/

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