# Specific 3D Printing Applications / Fields / Conferences > 3D Printing Prostheses & Robotic Limbs > Need a Prosthetic 3D Printed >  Need prosthetic front paws for border collie foster

## Nancy497

This is Eddie, my foster border collie.   He was born without ears or front paws and his two front legs are different lengths.   He has a pad on the bottom of each stump so he is able to walk.   However, he can only walk on grass (not hard surfaces) for short times, or else the pads get sore and bleed.   He generally sits up like this or lies down because standing is not comfortable for him with the two different length legs.   He has been shuffled amongst multiple shelters and foster homes all his life and no one ever thought he was capable of being a "real" dog.   He now loves to go for walks, but we only let him walk so far and then put him in a stroller to avoid stressing his pads.   He tries so hard to keep up with my other border collie.   I would love to get him some prosthetic feet to allow him to run and play with abandon.   He so deserves a happy ending.   I have no idea how to go about this.   Any suggestions or assistance would be appreciated.

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## RobH2

This sounds like a fascinating challenge.  I think I'd like to help out.  My first suggestion would be to cast both front legs. That sounds much easier than it will be I'm sure. You can search Google and find out what people are using to cast body parts. Alginate, a dental casting rubber might be the best. Then you'd do a plaster cast from that mold. From that mold you'd start designing and building a front paw. You'd need to decide if you want any articulating parts, like a foot on a little bit of a hinge to facilitate walking. 

The first step it to cast the legs and then figure how to hold (whatever the printed part is it) on. The second step is to test it, modify it, test it, modify it and sooner or later, have a design you could use. 

http://www.dickblick.com/products/ar...pbWRoCDczw_wcB

So, pull a balloon or condom over those legs (that will smash the hair down and simulate the dimensions the prosthetic will need to grip to) and cast them. Maybe a doggie "downer" will help with the process. I don't advocate drugging animals but, if it helps you walk someday it might be worth the one-time buzz. Althought, that looks like a very sweet dog. I bet it would let you do anything you wanted to it and not even fuss.

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## Nancy497

Rob, so excited someone is interested in helping. Is the process you are talking about one that is used for 3 d printing of prostheses?  I know nothing about the process.  His feet are gone right below the ankle so I don't think a hinge would work but then, I'm not sure about that either.  Have you done this sort of thing before?  Where are you located?

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## RobH2

Nancy, no, I haven't done it before. I am on a list to donate time to printing human hands in my area. So far, I have not gotten the call but am excited about that too. 

I'm in Baltimore, Maryland. And I know little about how prostheses are attached. Much of the basic structural mechanics is straight forward. Now, before I insult prosthesis designers here, I realize the tremendous amount of time and design that goes into modern appliances. 

What I'm referring to is a peg that attaches to a limb. That's sort of what we are talking about for doggy Eddie. We need a fake paw that will attach to his leg and take the pressure of of the stub so he can romp around without bloodshed and without it falling off. And we need to do this for under $30K...right?

Since we can't staple it to him, that's going to be the overarching challenge, keeping the thing on when he runs. It's going to take some research and some trial and error. The place to start might be with a prosthetic supplier. It would be good to see the various "attachment" strategies and borrow from them. 

What I do have going for me is that I'm an Industrial Designer by degree. So, this is what I get into. I have been running a 3d animation and illustration studio for 19 years so I'm also very good at modeling and 3d design. I just happen to have a 3d printer. 

Are there any dog prostheses out there on the market at all? Have you searched? I guess if we are going to do this we'll have to learn it together.

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## Nancy497

Oh, Rob.   Thank you for your interest, but we don't have that kind of resources for this.   I guess I was naive in thinking someone might donate their time and I also heard that 3d printing made this sort of thing so much more affordable.    I saw the YouTube video of the 3D prosthetics that 3D Systems made for Derby, the husky, and I was hoping I could do that for Eddie as well.   By the way, I mis-spoke, I guess his legs are gone from what might be considered the knee area, not the ankle.   Again, thank you for your response, but this is not a solution we can even begin to afford.

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## RobH2

That number was a joke. I didn't make it very clear. I'm willing to donate my time in helping you design it. I'd just ask you pay for whatever materials we use and consume: filament, padding, cloth, foam, etc. 

I think you could do it for a few hundred dollars. 

Rob

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## Nancy497

O.K.   Not laughing.   Mostly because it's hard to laugh when you're not breathing and that number took my breath away!    I hate to look a gift horse in the mouth, but I'm totally new to this, and I have visions of us trying multiple designs, racking up lots of costs and then not having it work.   Last thing I want to do is commit to something I can't afford.   Second to the last thing I want to do is pay for something that doesn't end up improving Eddie's life.  And, define "a few hundred dollars".  Is that more than "a couple-a hundred dollars"?

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## RobH2

Yea, I think so. I think a $200-300 would be sufficient. It depends on how handy your are and how much you feel like jumping in and just figuring it out. Filament is inexpensive. It might take two rolls. That's about $90. Cloth, webbing, thread, padding, etc., is not too expensive. Maybe that's $75 or so. Casting material might be $50 and plaster is dirt cheap, say $10. There will be some postage and a few other things, let's call that $75. So adding that up we have, wow, oddly enough, exactly $300. I'd rely on you to be handy and to be able to cut, stitch and mock up harnesses, supports and other aspects. We'd have to figure out how to do it but that's all just time. The materials aren't crazy expensive. FYI, I watched another doggy prosthetic video and YouTube and they talk about having raised $6000 to have a company in Denver make legs. So you know it costs more than that. https://www.youtube.com/watch?v=Wh1XOBp6rs4  and  http://www.orthopets.com/

The thing about 3d printing is that the materials are cheap. It's the design effort to create parts to print that is expensive. The 3d printer is just a tool and it has allowed mere mortals like you and me to make cool stuff that before would have been financially impossible. I guess you could go to China and get a plastics company to make you "one" phone case but it would probably cost $10K for the tooling and setup and molding of that "one" case. With a 3d printer I can print one in about two hours for less than a dollar. But, that printer can't print anything unless someone tells it what to do. If I can't find a phone case model on the web I have to make one. And, good 3d guys charge about $150 per hour to model stuff. You'd spend about 3 hours on that case so there is $450 just to get to the point that you can print it for less than a dollar. You are better off just buying one from Amazon. Buy a $15 hammer and give it to a master carpenter and see what he can do with it. Give it a 5-year old and see what he can do. So yes, while 3d printing is inexpensive on some level, it still costs something. The press does a terrible job making that distinction. 

So, I have the printer, I'm willing to invest my time doing 3d  work and design, I just can't do it all because I'm not there, wherever you are. Could you waste money and wind up with nothing, sure, that's always possible? But I'd bet we come up with something useful. It's not brain surgery. It's physics and some craftiness. 

I'm very willing to donate my design skills, time and printer if you want to pursue this. I'll help you along the whole way as much as I can. You'll have to be the carpenter on that end though. It might take a few passes but I think we can pull it off if you want to try.

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## Nancy497

I am going out of town for the weekend and will not be able to focus on this until next week.  You've givenme a lot of information to think about.  Thank you for that.  I will be back in touch next week.

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## MakersomeGuy

If you are still looking for help I can see what I can do. Let me know...

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## curious aardvark

hang on there is a dog with similiar problems where the prosthetics have already been designed and made. 
Your best bet would be to contact these people - I'll look the info up. 
It was 3dsystems who designed these prosthetics - very good publicity for them and they already have the files.
http://rt.com/news/216235-dog-3d-printed-legs/

Probably wouldn't need that much change to adapt the same basic design to your dog.

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