help printing a prosthesis
I came across a printable prosthetic model in open source on this site that I find very beautiful and very ergonomic.
I have a printer Ultimaker extended 2.
I turn to engineers to know what type of materials you advise me to print for different parts of the prosthesis (the socket, the part in contact with the ground ...)
Hi, I am a prosthetist. Well I have a few concerns about the design. It is a cool looking design.
Is this something that will actuall by used or is this just for a print project?
First the socket is very short. this will most likelyt be an issue with stability. to get good control of the limb they typically need to be taller for better limb leverage.there are shorter socket designs but they have specialized suspension mechanisms.
Second would be build volume. you have a max of about 12 inches in build height. The average knee center for someone is typically 19-22 inches, and printing something like this in multiple sections would not be advised.
The knee center of this design is pretty anterior which would most likely cause the knee to buckle forward under weight.
The foot is a running type foot so standing and walking would be awkward.
Now, those things being said, these are the materials I would recommend:
for the socket in should be in 2 parts. The inner would be a flexible inner socket out of something like Ninja Flex or TPE. the outer frame of the socket should be something fairly rigid but with some flex, ABS, or the carbon fiber infused filament. The tibial/foot section should definitely be rigid. The carbon fiber filament.
Now, to say that these parts can be printed may be an oversimplification of what is needed. Looking at torque, load bearing, and other factors this as is just printed may snap at the pivots. they should be stainless steel. some of the connections like where the knee extension cylinder sits would definitely need to be beefed up in my opinion. I think doing some material analysis would be good.
I hope this helps some. any more questions let me know!