Power Glove
This project was built as an assignment for an engineering-based Physics 1 class at National Park College by Trace Buttrum and Layne Kerley. We could have chosen any project for the assignment, and this assignment was more about the documentation process rather than the project itself. We chose to build a 3D-printed glove designed to enhance the wearer's grip strength which we have dubbed "The Power Glove".
Supplies
The necessary tools and materials include a 3D printer and the necessary filament, elastic bands, super glue, rubber bands, JB weld, cardboard, digital calipers, and duct tape.
Some of the materials were purchased privately by us, but we could not have completed this project without the Maker Space and Mark McCorkle, for kindly letting us use the space and tools necessary.
The Process
We began the assignment by discussing our idea and the end product we desired, as well as how we would engineer it. We thought of an idea we have seen before, which is a mechanical hand controlled by strings attached to the wearer's fingers. We planned to secure the strings to the plate on the back of the hand and run them to the first finger segments, where it would be secured to a separate string connecting to the next segment, until the end of each finger. To aid in re-opening the hand, rubber bands and springs would be run so as to retract the fingers when force was no longer applied to the strings.
To begin the design process, we had to find the optimal design software. Trace had experience with AutoCAD, though after several recommendations we settled on Fusion360.
We began by measuring different parts of our hand. Initially, we planned to secure the glove to a wrist with a ball bearing to provide security while still allowing rotational motion. Shortly after beginning the initial design, we decided it was simpler to make the glove itself more secure and no longer develop the wrist. The fingers were planned to twist lock into the glove, with the segments remaining connected. When the first print was completed, several problems became immediately apparent. The square design of the glove left rough edges after the supports were removed. The finger holes and finger segments were too small for our fingers to fit into. We attempted to remedy this by removing material with a dremel, though this did not end up working well.
After the first print was put aside, we attempted to change the measurements in the initial design. The second print had similar problems to the first, and was subsequently shelved.
The third print began as a complete redesign of the glove. The main body would have one large hole for four fingers. The finger segments would be permanently attached to a bar that would lock into the body. The strings would attach to an external piece that would be drawn back to provide tension, and locked into the palm of the glove. The print itself came out with fewer problems than the first two, however the range of motion was too limited. Providing proper range of motion required the removal of too much material, so we set this print aside as well.
The fourth print was another redesign using a method to connect multiple pieces using chain links. This method was not suitable, as the links on the print broke quickly after we attempted to wear it.
The fifth and final design appears to be much less problematic than the previous iterations. The main body of the hand was designed in two pieces, connected by elastic bands super glued to the interior. This provides a cushion and is capable of fitting multiple sizes of hands. At this point, we decided to design the fingers as accurately as possible. We used digital calipers to measure every segment of our fingers, and we quickly learned that each finger was similar in size and shape. This allowed us to design one finger, copying and resizing it for every finger. These finger segments were also more rectangular, where the previous prints were cylindrical.
What We Learned
Through this project, we have encountered several hurdles. With each, we continued to make improvements and learned something new, from new ways to use 3D-printing software to the anatomy of the human body.
With every iteration of the glove, we learned new processes in the software, making certain parts of designing the glove easier. We learned shortcuts to cut material, add material, shape the material, as well as developing a better understanding of how the print will come out.
The fingers provided insight into human anatomy, with the rubber bands, strings and springs acting like tendons and muscles in a real hand, though our concept is much more simple. With this idea, we are able to tune the strength of the fingers by adjusting the length and tension of the rubber bands and springs.
We learned too late that the optimal way to design a hand for a 3D print is to use a 3D scanner. We plan to utilize this information in our future prints.
Looking Forward
In the future, we would like to refine this idea into a complete and functional prototype. After that, we are interested in the idea of designing similar prototypes for other parts of the body to provide different benefits.