I have been doing more reading and I have a few questions.
1.how do i make a visor that has edges EX. The MKVI from halo 3 and how it has those indents in the middle of the visor.
2.Interchangeable visors
3.making a visor that is cracked and looks natural and not planned.
4.retrofitting a jetpack for a h3 MKVI (like in red vs blue)
5.How to do the mic/speaker system i mentioned
For starters....the best way to answer all of these questions is to read, read, read, and then read some more. Also, as it was mentioned earlier, you can scale the pep models using pepakura viewer, you don't need to buy the program for it. Here are some quick outlines though.
1: The easiest way to add the visor detail is to layer two visors together. The inner visor (the one closer to your face once it's on the helmet) will be left untouched. On the outer visor, cut out the details with a dremel, use needle files to clean up the corners of the cuts, and then sandwich it up to the inner visor. An alternative to this is building a plug mold of the visor, and using a vac table and heat to mold a visor from thin polycarbonate.
2: A popular way to mount visors into helmets is to use some epoxy putty to hold a nut or bolt on either side of the visor opening in the helmet. You then drill two (or more depending on the visor shape/ design) holes in the visor to mount it to your epoxied-in nuts/bolts. Using this setup, you could easily swap out visors.
3: Study pics of cracked glass online, then draw out the "cracks" on your visor with some washable marker. Then use a dremel/marking awl/needle files to score the lines into the visor. Lastly, wash off the marker.
4: If you are looking to build the jet pack from reach, download the pep file and build it up to the resin stage. Now you can either add in a spacer behind it than matches up with your chest piece, or you can trim the mounting surface of the jetpack until it matches the chest piece. Personally, i think the spacer would look better, but try to keep the jetpack as snug to the chest piece as possible. You could do all this either using cardstock, and just making your own templates, or you could use eva foam to do the entire jetpack ( would keep it nice and light). I like foam, and would go that route, but its entirely up to you!
5:Read through the " Help for electronics " thread. There's a ton of good info in there.
Good luck with your build!