Before we get into this, I'll say that I borrowed some ideas from flaming_pele!'s Power Loader costume: http://www.instructables.com/id/Aliens-Powerloader-Halloween-Costume-1/. I will give him credit where it is due along the way.
There have been many Power Loader costumes before, but this Instructable will show how I made mine on a modest budget in a pretty short time.
Step 1: Inspiration and Goals
Shortly before beginning construction, I looked around to see what other Power Loader costumes had been made before. There were many awesome ones on YouTube. And, of course, I saw flaming_pele!'s cool one on here. After looking at these previous attempts, I made observations and decided on some goals that I wanted to achieve in making my own:
Firstly, I wanted mine to be truly life-sized. A lot of other Power Loaders were slightly scaled down, and the foot stilts especially weren't as tall. That's completely understandable, especially in terms of balance and movement. But I wanted mine to be the same size and proportions as the original. I also wanted it to be screen-accurate on all other details. I wanted the exact same shapes, colors, and structures that the original had. I wanted it to match it as closely as possible in all physical details. If I was going to bother making a Power Loader at all, I wanted it to be the Power Loader. All or nothing. And, of course, I wanted mine to be practical. I wanted to be able to walk in it and move the arms, all with a reasonably stable balance and control. I'm not mechanically inclined enough to have figured out a way to make the pincers move, but other than that, I wanted joints to be articulated, complete with pumping hydraulic cylinders.
And finally, for the ultimate challenge, I wanted my Power Loader to have two qualities, when compared to other attempts: made cheaper and easier. Most other attempts didn't have any budget estimate, so I had to figure the always-assumed standard of spending as little as possible. But I also wanted this to be made quickly. Other attempts had been made over the course of several weeks, even months. I wanted mine done by the first week of school (beginning construction in mid-August). In the end, I wanted the best of all categories: cheap, quick, functional, and accurate. I then began to make the machine.
Good research and reference was critical. I used the Sideshow Diorama of the Power Loader as a constant template, taking precise measurements and scaling them up 8 times to be full sized. I also went through the movie and took screen-caps from its featured scenes, and also gathered behind-the-scenes images. It's always fun to understand how the original was made.