D.I.Y Robotic Hand
Here is a demonstration of the finished product.
Downloads
Supplies
The following materials were used to create the robotic hand: Styrofoam, an X-ACTO knife, paper clips, rubber bands, fishing line, hot glue, servo motors, Arduino Uno, pliers, sanding block, toothpick, and a marker.
The Formulation
Initially, place either hand and corresponding wrist on a piece of paper and trace around it. Then, around each finger, create a rectangle and determine its height and width; this makes it easier to obtain the measurements. Using the recorded measurements, outline the fingers, hand, and wrist on the piece of Styrofoam using the marker.
Slicing & Dicing
With an X-ACTO knife in hand, follow the placed outline to cut out the fingers, hand, and wrist carefully. To ensure the rectangular prisms resemble actual fingers, utilize the sanding sponge to smoothen the various edges and vertices. Next, on each finger, draw where the joints will be. Once marked, use a 45-degree cut to separate the three joints.
Attachment
Once each finger's joint has been detached, use your sewing needle to thread the fishing line through the hand and into the joints. To secure the fishing lines, insert multiple paper clips onto the wrists and allow the lines to go through them. Afterwards, hot glue your stretched-out elastic bands onto the fingers; this allows them to bend back into place once the elastic bands contract. Next, excavate two areas on the wrist so the servo motors can be hot glued into it. Lastly, feed the fishing line through the motors; this allows the fingers to contract and expand autonomously.
Programming
Finally, the code must be written to enable movement throughout the fingers. Start by designating names for the motors such as servo1 & servo2, and providing them with pulse width modulation (PWM) pins like 10 and 11. After, create a void loop with your movement title being labelled underneath. Now with a void loop, the motors can go from 90 degrees, slightly pausing, then returning to 0 degrees; repeating this action indefinitely.