This is a simple robotic arm that can record and replay positions. It is made from easily available materials, like cardboard and hot glue, which makes it easy to build.
You control the arm with a graphical interface on the computer that sends data to the Arduino that controls the arm. There are sliders to control each servo, and buttons to record positions and replay what you've recorded. You can also save and open past recordings.
Here's a demo of it in action:Instructions
1.) Download and print out the Cardboard Cutout Template in the Custom Parts and Enclosures section at the bottom of the page. Use that template to cut out the cardboard parts.
2.) Assemble the arm part using the video above as a guide. The build starts at 0:22 of the video.
3.) Build the circuit based on the schematic at the bottom of the page.
4.) Download the "Robot Arm Arduino Code" at the bottom of the page in the Code Section in the second tab. Then upload that to the arm.
5.) Download the "Python User Interface" code at the bottom of the page in the Code Section in the first tab. Then, open it. You must have Python installed to run it, which can be downloaded from here: https://www.python.org/
You will also need the PySerial library for Python (https://pypi.org/project/pyserial/). You can install it by running "pip install pyserial".
6.) Plug in the arm, run the "Python User Interface" code, and type in the COM port of the Arduino (This can be found in Device Manager on Windows). Now you're ready to use it!
If it doesn't work, try to increase the time.sleep(0.15) on line 20 of the Python code to something higher, like 0.2 or 0.3