OK, this summer I am making my pack. Since I am living at college now it is a little hard to construct it (no power tools in the dorm geeze! haha) and so I'm currently gathering the parts so I'm ready. My main concern is how I'm going to make two things on the pack: One is how do you guys suggest making the “bumper”? I know people have said to use hotwheels track, etc., but I want to make something a bit more sturdy. . .what do you suggest? My second question is how you guys went about rounding the box where the handle meets on the proton gun (the bottom handle on the left side). I have a few ideas, but wanted to ask everyone first. I'm sure I'll have more questions later, but this is it for now. . .thanks.