It's cute, It's polite and it is really deadly. It's a turret from Portal. It moves, has light, has sound, and something that my previous Portal project did not have: Camera tracking.
The turret is controlled with an Arduino and a PC. The arduino handles the movement and the light, the PC processes the video from a webcam to decide where the turret needs to aim and provides the sounds for the turret.
When no computer is present, the turret automatically switches to manual control. In this mode the turret can be controlled by a joystick, though there will be no sound.
The turret is full 3D printable and requires very little additional tools to make. This does not mean that this is an easy project, but it is manageable with some basic 3D printer, electronics and programming skills.
For more projects like this, go to my site: http://ytec3d.com/
The design was the the hardest part of this project. Not because there are no reference images or because the turret is that difficult in its design. It is because the turret does things that are not physically possible.
At first I wanted to make this turret so it could open and close as well. The issue is (as you can see in the images) that the guns of the turret almost touch each other when the turret is closed. There simply is no room to have a turret with all movement that can also open and close. The solution was a compromise where the turret only moves and doesn't open.
Also the design doesn't include a real space for the electronics (as seen in all the photos and videos). After I built mine i did a last wave of improvements where I hollowed out the top of the turret. There is some space there now to place electronics if you can manage to make them small enough.
The rest of the design was only a matter of time. First the turret was designed in one piece in Solidworks to get the design right. Then this part was cut up into smaller pieces and mechanisms were added to make the guns and eye move. All in all the design took between 40 and 60 hours (I don't really track the time).
(Reference image to the right made by: Tyler Garrison, for another turret project by CitizenSnips and modified by me to show the flaws in the turret's original design)