Here's the lowdown: All of the Portal turrets out on the internet are either a)minifigure scale or b) incredibly large and detailed scale. Unfortunately, the minifigure scale models look somewhat... squat. Let's face it, there's a point that that scale can't handle, and the curves of the Portal turret put it beyond that point. So I decided to do a slightly larger than minifig. scale turret.
The turret in action with a test subject (see Chell and Portal Gun creation):