A Robotic Hand

In this project between both stem math and stem computer technology class we made a robotic hand and we coded it to make it be able to pinch the pointer and thumb finger.

when you are making a robotic hand you will need the following materials:

• Servo motor (5 motors)
• Arduino board
• Styrofoam
• Glove
• Wires
• Breadboard
• Battery and battery buckle
• Rubber band
• Fishline or wire
• Glue gun and box cutter knife.
• Paper clips
• Plyers
• Rulers
• Sandpaper
• Needle

When creating the foam hand these are the steps you must follow to be successful:

1.The first step is to trace your or a group members hand onto the Styrofoam

2.Second step is to measure your fingers and hand to make sure your foam fingers are very close if not exact to your hands measurements

3.After cutting rectangular prisms our of the foam you shape it to your fingers dimensions using sand paper.

4.You must sand your fingers into a cylinder shape.

5.Then you want to cut the fingers into three different sections with 45 degree angle cuts where each section will rest on one of the other sections. for example the tip will have a cut at the bottom, the middle section will have a cut on the top and bottom, and the bottom section will just have one cut on the top.

6.you follow that step for every finger except the thumb, for the thumb you only make two sections because it is a much smaller finger and has a different build then the rest.

7.After cutting out all the fingers you cut out your palm and a bit of your forearm and sand it to make the sides smooth and more realistic.

8.To attach your fingers to your newly cut palm you get a needle and fishline and thread the needle through the finger and into the palm.

9.To keep the fishline attached to the palm you get paper clips and cut them into small pin shape pieces to thread the needle and fishline through.

10.Then you add elastics where the knuckles on your fingers are to keep them close together but still allow it to be realistic and move around.

to connect the servo motors you will need to follow these steps:

1. Cut a piece of foam and add it to the bottom of your original forearm to mount the servo motors on.
2. Trace five servos onto the newly added foam
3. Connect the servos to the foam using hot glue to secure it and keep it from moving
4. Using the fishline that was thread through the forearm rap the fishline with the servos to full connect your servos to your fingers.
5. Now your fingers are connected fully and the servos just need to be powered to make your hand pinch

The servo connections we use in this project are as follows;

Orange Input - Signal Input

Red Input - Power Input (VCC)

Brown Input - Ground Input(GND)

All servo motors VCC and GND connect to the motor shield VCC / GND inputs.

The signal inputs of all servo motors are connect to the motor shield ~PWM 3-5-6-9-10 respectively.

To start coding the servos:

• start off by adding the servo library into your code
• name each servo as which finger they will be controlling
• add the newly named servos into your code and choose which pin they will be connected too
• make commands using each servo and changing the value between 0-180 degrees, 0 is when the finger will be fully closed and 180 is when the finger being full open
• get your commands finished and add then into your loop so they will now control your fingers
• now you can run your code while it is connected to and Arduino and your fingers should now work properly if steps are followed properly