We realized that the other fingers would get in the way of drawing with our current design. To solve this, we needed a way to hold all the fingers down aside from the writing finger. The simplest way would be cutting the string pulling that finger down, so the rest of the fingers would still pull down. This would mean losing the functionality of one finger. Instead, we decided to add a clasp to the string. This still requires the use of the other hand, but the user can easily alternate between full hand control and only holding out the writing finger.
The final model of the Swiss Army hand is a prosthetic for the physically impaired that is meant to help the user store and use tools. The hand comes equipped with a screwdriver and a wrench that are fixed onto a set of bars that are rotated by two wheels. The initial idea was to have a different tool for each finger however, we soon realized that in order for the extending and retracting mechanism to work correctly, the maximum number of tools was 2 tools. Once our group decided on which tools to use, we designed around them and figured out what other mechanics the hand had to have in order to work correctly. The inspiration for this came from a swiss army knife and from the superhero Wolverine. The multiple tool idea came from the concept of a swiss army knife, and the retractable tool feature was inspired by looking at the claws of the superhero Wolverine. The two tools are fixed onto two acrylic bars that attach to two rotating wheels. When the user bends their wrist, the fingers close and the two tools push out and extend past the fingers. When the user returns to the natural position the tools retract back in.
Idea: Throughout 5 weeks Henry and I have worked rigorously on modifying the Snap-Together Robohand, designed to be a cheap 3D printable prosthetic for children. Our idea originated from our love of baseball. While understanding the limitations these children had, we came up with a design to open and close a baseball glove with the movement of your wrist.
Design: We used a 3D modeling software called Rhinoceros to redesign all the pieces we needed to. Our first step was to look at all of the pieces of the hand. We realized that only half of it needed to change in order for it to make the motion we wanted. We started sketching out everything that needed to change and then designed the original pieces that we were going to change in rhino. After that was done, we started the modifying process. This included angleing and extending pieces, as well as creating completley new fingers that would be in different areas of the hand. After designing and printing all the new pieces, we ran into several problems and went back into Rhino to fix them. We had to create larger holes in the fingers for the elastic and wires to run through and we cleaned up some of our designs. Running into even more problems, Henry and I as well as another group met together and decided on a few key points in making our hands sleeker and more efficient. We went into another 3D software program called Inventor. This allowed us to join many of the pieces, cutting down on the total amount we had to print in half. Inventor gave us the ability to put all of our pieces together and see the movement that would happen when it was printed. Although we are still working out some details and issues that need some cleaning up, we have a prototype that looks leaps and bounds better than our very first. We intend on continuing our work on the Baseball Prosthetic after the end of NuVu. Our overall goal is to have our hand available on Thingiverse, a huge open source 3D printing community. This will allow anyone with acess to a 3D printer to make our hand and use it. We are very proud of the work we did for this project and hope that this inspires more people to get into prosthetics and 3D modeling.
We attached a pen using electrical tape and tried writing with it. It didn't work very well, but it was a major improvement over not being able to write at all (with a current-generation robohand). We held down the other fingers during testing as well, and we plan to try the same but with the pen attached to the thumb, side of the hand, and other locations.
The Snap-Together Robohand was 3D modeled and open sourced to give people a cheap and easy way to obtain a prosthetic. Normal prosthetics can cost in the tens of thoasands of dollars. Although the original Robohand can close its fingers, it doesn't allow the user to do much else besides picking larger objects up. That's why the DIY Prosthetic In the DIY Prosthetic studio, we were given the Snap-Together Robohand as a model and were told to modify it into a hand with a specific use. The Baseball Prosthetic uses a claw like closing motion which is needed to shut the glove. Moving the wrist up and down will open and close the glove.
To preface what we did I would like to start by saying that Catherine and I are both musicians. I am a classically trained violinist , and she is a concert pianist; and thus we could not imagine our lives without the use of our hands which in turn provide us with creative outlets but furthermore provides us with motivation to equipt others who do not have our privelages with a means of self expression.
In this studio, our goal was to expound upon the functionality of the Robohand( the original 3d printed hand) by making it more utilitarian, friendly, and durable. The results were the dawn of the "Ratchet Hand,". An important aspect we wanted to focus on was aesthetics. For children especially, we found that art is crucial means of self expression. We thought that certainly everyone should have the ability of self expression, and having no hands should not be a limiting factor.
The main structure of our Ratchet Hand is based off of the RoboHand. The RoboHand is inexpensive and available in .stl form worldwide. In our project, we focused on reinventing the fingers and knuckle board. To begin the design process, we started off creating a bridge that would hold artistic utensils of specific circumferences. We found out this was really inconvenient and bulky. So, we changed it into a spherical shape. This allowed for more flexibility and created more of a curved and smooth surface. After our first 3-D prototype, we found that the sphere was very bulky; as a way to keep a smooth shape, we went to a cylinder shape with lofted edges. This way, it wouldn't be as bulky but still maintain a nice surface. One major component of our hand is the ratchet mechanism. The ratchet allows the cylinder to move and give multiple positions for the person to use the utensils from. It also holds the position in place.
We changed the design from strictly art "instruments" but to general utensils. To fit the utensils, we were going to use a threaded screw concept so that way any circumference pencil, pen, or marker could fit. Unfortunately, we were unable to complete this idea. In the end, we had specific circumferences for different utensils. Our final Ratchet Hand can hold a pencil, sharpie, paintbrush, fork, and knife. It is multifunctional and universal for many to use.
We are developing a couple new interchangeable ratchets, that are more germain to the task in which they will be used: a ratchet cylinder for eating utensils (solely), a ratchet hand for writing(different circumferences). Also one that has a pencil sharpener and maybe even a lazer!
Thank you to team ratchet, and everyone at nuvu for inspiring us to do what could not be done.