My first attempt at making a mannequin for C3PO wasn't successful. I had tried the very slim male mannequins (the ones with a chest size of 35), cut them down and tried to get the torso plating to fit but it wouldn't work. The problem area was with the underarm area and just the overall thickness of the body. I even tried the foam half height mannequins. The torso shell would fit only after I shaved away almost half of the body off. However, it didn't provide the structural support I needed. PVC pipe works great if you just want to hang a wearable costume but doesn't do any good if you want to animate his arms. And then 1 day I saw what Mardon had done for his 3PO and that gave me an idea. As you can see to the right he created a shelf for the neck and arms and uses a pressure fit from the torso to the pelvis area. I will probably take that a few steps further with mating PVC floor flanges on the underside of the shelf to mate with the hips and legs. For the lower section I decided to try a combination of a wood and PVC frame with foam filler to keep the fiberglass in proper position and provide stability.
I am using a CF3 for the sound system. Those sounds would be triggered by 2 methods. One would be by depressing one of the remote keys on a 12 channel RF unit from Cold Fusion. Other sounds would be triggered from a random set of selected MP3 files triggered from the motion sensor placed in his abdomen. As you can see to the right, the back of the torso has been vented for the 2nd speaker & venitlation of electronics. I used a rotozip bit to drill out the slats. As you can see to your left, I added the perl beads for the chest greeblies and restraining bolt holder. The front of the abdomen/pelvis has a hole for the motion detector that will trigger varied responses from the CF3. The back has a few slats cut in to allow a smoother mating of the torso to the abd/pelvis assembly. Later I will drill additional holes for the cable ties that will be used to hold the various wires C3PO normally has on his belly.
I just need to decide if I want to I want to power the systems from AC or DC power. I will probably run a power cord and connector to the rear left foot (the heal) in case I want the option.