Great project!
Neat project, but I don’t know how much functionality this prosthetic will actually provide. I have casted and fit some patients for fingers from Naked Prosthetics and you would be surprised how much they can bang up the stainless steel and high density plastics with use.
The elastic band really needs to be replaced by a rigid structure that can take full advantage of the wrist flexion for any actual grip strength.
you would be surprised how much they can bang up the stainless steel and high density plastics with use.
I am absolutely not surprised, and neither should anybody: just look at the beating a simple pair of shoes or gloves take simply by wearing them normally: when you think about it, the human body is designed to withstand the same beating and self-repair all the time for an entire lifetime without any visible drama. It’s nothing short of amazing!
As for how long the 3D-printed finger will last, it depends on what material you print it out of, Some plastics are properly tough. But yeah, I expect the distal at least will need changing regularly.
But that’s the beauty of 3D-printing: you can crank out as many new spare parts as you want almost for free. You can get a decent printer for less than $200 these days, and a $20 roll of filament would last you for a mightly long time if all you did was print small fingers with it. So even if the finger isn’t that durable, you’re not breaking the bank.
The elastic band really needs to be replaced by a rigid structure that can take full advantage of the wrist flexion for any actual grip strength.
I’m not sure increasing the grip strength has much effect without some kind of grippy material on the distal. Without it, however hard you grip, the finger will be slippery.
But hey, it’s a tinkerer’s project. I’m sure anybody who prints this will want to improve on it to make it functional. And for the price, you can’t go wrong 🙂
when you think about it, the human body is designed to withstand the same beating and self-repair all the time for an entire lifetime without any visible drama. It’s nothing short of amazing!
Yep! Most people underestimate the amount of friction and force a body in motion can create!
As for how long the 3D-printed finger will last, it depends on what material you print it out of, Some plastics are properly tough. But yeah, I expect the distal at least will need changing regularly.
Yeah, I’m not super familiar with the new widely available filaments. We typically use a lot of polypropylene in our field, but a lot of that is because it does well with skin contact.
You can get a decent printer for less than $200 these days, and a $20 roll of filament would last you for a mightly long time if all you did was print small fingers with it. So even if the finger isn’t that durable, you’re not breaking the bank.
Huh, didn’t know they were getting that low now a days. Any real requirements as far as processing power for your computer?
I’m not sure increasing the grip strength has much effect without some kind of grippy material on the distal. Without it, however hard you grip, the finger will be slippery.
Grip always helps, however mechanical leverage is doing the bulk of the work depending on what finger(s) we’re talking about. The other sound fingers will usually provide adequate grip, but still need help with distributing weight or force. I think most digital prosthetics utilize a rubberized silicon that kinda feels like a soft tire tread.
And for the price, you can’t go wrong 🙂
Especially for fingers. Unless workers comp is involved most people are paying out of pocket for the custom stuff. Apparently insurance companies don’t think your fingers are very vital to your overall health.
Any real requirements as far as processing power for your computer?
None. The printer does everything. All you do is feed it a gcode file.
Although in the case of this finger, you need to install OpenSCAD and regenerate the STL or 3MF files with the right measurements for you, and then you need to slice the parts to generate the gcode files to feed to the printer. So you do need a computer, but it doesn’t have to be anything special.
I think most digital prosthetics utilize a rubberized silicon that kinda feels like a soft tire tread.
I’ve used Sika Biresin U1305 polyurethane for the soles of custom footwear I made for myself. It cures into a grippy, durable hard rubber. I would definitely try it on something like a prosthetic finger. It might be a bit too hard but the durability is really good, since it’s good enough to make custom shoe soles out of.
