From about October and December, I saw a video by henry3136 on YouTube where he made the sentry from Team Fortress 2 in real life using an Arduino Uno. At the time, I didn't know much about circuits aside from some basic knowledge, so I was intruiged. I did some research about Arduinos, and realized that there wasn't the source code in the video's description. not only that, but I also have to make the model of the sentry itself.
I found a papercraft model to make one, so I figured I could cut out the shapes from the blueprints and trace them onto cardboard. I went to Rasterbator and upscaled the template so the sentry wouldn't be as the size of the breadboard.
This is not intended to be a step-by-step guide on how to make your own. I just listed the parts in case if you wanted to know what I used. You can try to make this, sure, but don't blame me if something goes wrong.