Wrex 3D Printed Prosthetic "Magic Arms"

Please take an immediate time-out to watch the video on the 3D Printed "Prosthetic Arm" / "Arm Strengthening" Device called: "The Wrex"

WREX = Wilmington Robotic Exoskeleton

"Magic Arms" Story on Stratasys Site

Did you get a little "misty" during the video?... I did





I would like to make a "Call To Arms" amongst the RepRap community to design a similar device, make it open source, and get it out on the web (thingiverse, github etc) ASAP.

I know I will be making an attempt over the next few months.

Printable devices like the Wrex, could help deliver on the promise of a charitable, humanity bolstering RepRap machine.

Plus... Who here wants to know if a "Man-Sized" version of the Wrex could be used to amplify the strength of a healthy person?

Edited 2 time(s). Last edit at 08/01/2012 06:55PM by Idolcrasher.

I love this.

We need to put our heads together and design something better. Anyone with a background in bio-mechanics out there?

Any ideas for sourcing the vest and forearm pads/cups? That is probably the toughest bit. Not to buy, but to get the drawings/dimensions to design the human interface. The rest looks straightforward. Obviously fully parametric designs are an absolute must.

Integrating a micro-controller into this device might be very useful as well. Not for control, but rather to gather motion data for patient evaluation. It might be useful to gauge motor control and aid in evaluation - like when to step up to the next set of rubber bands to continue building arm strength or to gauge the fluidity of a patients' movements.

Is it just me or is the world changing before our eyes?

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- akhlut

Just remember - Iterate, Iterate, Iterate!

[myhomelessmind.blogspot.com]

Am I reading it right? You want to make a competing arm to promote reprap?

There is already a open source arm freely printable by any 3d printer.

robertwse Wrote:
-------------------------------------------------------
> Am I reading it right? You want to make a
> competing arm to promote reprap?
>
> There is already a open source arm freely
> printable by any 3d printer.

Nope,

You are not reading right

... we had some talk in past regarding artificial muscles and other methodes of moving/rotating joints or applying forces.

There could be some interesting methodes with strings or hydraulic pistons for extreme lightweight structures in the active area and the heavy parts (motors, batteries, valves, ...) sitting in the base of a wheel chair.

On the other hand there is a mature development 'community' for exo-sceleton and -prosthetics for military and space applications, so maybe we can find some good ideas there too?

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

VDX Wrote:
-------------------------------------------------------
> ... we had some talk in past regarding artificial
> muscles and other methodes of moving/rotating
> joints or applying forces.
>
> There could be some interesting methodes with
> strings or hydraulic pistons for extreme
> lightweight structures in the active area and the
> heavy parts (motors, batteries, valves, ...)
> sitting in the base of a wheel chair.
>
> On the other hand there is a mature development
> 'community' for exo-sceleton and -prosthetics for
> military and space applications, so maybe we can
> find some good ideas there too?

For sure, for sure

The first stab I take at this will surely be simple and un-powered.

Mounting an arc reactor will come later

That's an Awesome video. You just have to love 3D printing when you see something like that.

The only thing that spoilt it for me was that Stratasys files it under /IP on their website page. Fail. Take a little more care, big business.

I Agree, we should be doing more awesome stuff like this with RepRap.

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[richrap.blogspot.com]

Greetings all,

I'm pleased to find that another reprapper had already posted the link to this amazing story. From what I can tell, the WREX uses rubber bands and provides a partial cancellation of the gravity load (of Emma's arms), so that her available muscle strength is enough for her to move her arms against the remaining gravity forces. If you re-watch the video, you'll see one of the rubber bands being replaced. IMHO, the benefit of using rubber bands is that they're easily adjusted and/or replaced by a non-engineer -- and require neither a power source or a controller. So long as rubber bands work for Emma, I think simple, such as using rubber bands, is a good approach. Her parents can replace stretched out rubber bands or put in stronger ones as Emma's arms grow, and there are no batteries to carry along/replace and no firmware to adjust.

However, if rubber bands cannot keep up with Emma's (or other people with this condition) muscle deficit, then I think there's a strong case for putting in powered actuation.

Whatever we do, I think we should take care to credit the designers of WREX and try not to cause them any headaches.

I would love to know exactly what s going on in that rig. Is it canceling out the weight of the arms?

How can it do that and still allow free movement?