this helm was made from light weight aluminum for a theater group in Vancouver. the steps are basically the same if you were to use a heavier material such as 14 gauge crs.
Step 1: Build a Frame
measure the head around where hat would sit, from front to back at the same level and from ear to ear. remember front to back will be longer than side to side. bend your brown band to fit leaving room for pading, then attach the two other strips. i used pop rivets but for any battle ready helm you will need solid rivets and a welder.
Step 2: Pattern
you know want to get a piece of paper and fit it into one of the 4 sections produced by your frame and trace it and then cut it out. transfer this onto the material you have chosen for the helm and cut it out. i used snips for this one but for nything heavier a jigsaw with metal cutting blades is best.
Step 3: Forming the Plate
you now want to form yuor plate into 1/4 dome, 4 of these total. you can iether dish it to shape (forming it by hammering it into a mold) or by rising it (forming it over a "mold", i find this is best as it does not thin out your material, for this prop i raised it over a trailer hitch ball lol ) you want to check your plate for fit s you go and if you hammer work steel you will also need to temper it as you go or it will get brittle.
Step 4: Attach Your Plate
ive been a little vague on fitting the plate, you want to make sure your plate covers half of each spine of the frame it is to be attached to allow for fastening. soooooo insert and fasten your plates all four. some people pre drill holes for rivets and this is a good idea but only on one side to be riveted ie. the frame but not both frame and plate. trust me they wont line up.
Step 5: And Off to Battle You Go
so after the plates are in, clean it up, knock some of the dents out from forming, add some padding and maybe a leather chin strap grab your sword nd shield and go pillage some village. lol kidding dont do the last part. a little quick demo. cheers eh