Making iron man armor - Having trouble scaling pepakura files.

Sorry if this is the wrong section, was unsure where to post this.

So I just spent the past 5 or so hours today cutting and gluing iron mans mark 7 helmet. Only to find out that it doesn't fit. Can someone please explain the easiest way to get the proper size of the armor. I have gotten pretty decent at gluing pepakura together because of my failed attempts at getting the scale the right size to fit me.

 

There's no trick, just measure your head to get an idea and then estimate. Only build what you'll need to get an idea if it will fit or not, if it's too big or too small, resize accordingly and try again.