After examining and building the original RoboHand, Sam and I took notes of what needed significant improvements. The RoboHand seemed like a very rough design and was difficult to get working and adjusted the way we wanted it. Main problems that we found were that the original design was difficult to string up and adjust, it could really only grab larger objects, and it was a bit rickety. To solve these problems, we basically re-designed the entire hand.
Starting off with stringing it up, we did away with having to tie knots on the body of the hand. It was basically impossible to string up each finger perfectly. Some of them might have less range of motion, and others would bend all the way. Instead, we took ideas from the Violin. In order to tune a violin, you take out a rod, twist it to your desired setting, and ram it back in. It stays in the hole because the tunnel is tapered as well as the rod. We implemented this idea into our hand and now it is much easier to string it up and make fine adjustments to the fingers. It also looks extremely cool.
The knuckles also got a make over. The original RoboHand had a straight knuckle and didn't allow for a wide array of movement. By angling it, much like a human hand, we could have a wider range of movement and possible more grip. Unfortunately, this meant that we would have to change the side bars so the entire hand could rotate and still have parallel side bars. We also changed the position of the thumb to under the index finger which would make it more like a claw. This would make it easier to grab small objects. At first, we made a lot of mistakes. Our 3D models weren't closed polysurfaces, which became a huge waste of time and was extremely frustrating. But after making sure all of our objects were correct, we were finally able to print.
Sadly, after printing out all of our pieces, and finally getting the change to put it all together, we realized how many mistakes we really made. The pieces all had too tight of tolerances and would either not fit together, or have a lot of friction and not move freely. The only thing that really worked was our solution to stringing it up. It, for the most part, worked perfectly and would be a great design change for all of the other groups "hands".