Several people have said they'd love the thumb to be more opposable, like the Flexy Hand. That's proving to be a problem. When I try to figure out where the hinges should go, I get stuff like this.
- bad thumb.jpg (34.02 KiB) Viewed 1607 times
- bad thumb 2.jpg (32.68 KiB) Viewed 1607 times
As you can see, the proximal phalanx has nowhere to go because it hits the hand. It's also too far to the side. This makes the angle between the thumb and the index finger an acute 'v', when what we want it more of a circle.
The problem is that the Raptor hands put the thumb out to the side, while the Flexy Hand cups the hand, pushing the thumb inward. You can't do that with Raptors because they have to print lying flat on the palm. The Flexy Hand prints in a completely different orientation.
The most likely thing I've thought of in the last few days has been having the thumb hinge be an extra piece that you add on. Francisco Fernandez just posted something along these lines.
- image.jpg (98.98 KiB) Viewed 1607 times
It looks functional, but I'd like a simpler system than that.
Another thing that bothers me is travel system. Is the wiring going to be a problem when the fingers bend 180 degrees and the thumb only bends 90? How does that work on the Flexy Hand?