Scope: For this project, I was to create a thermoformed object that goes somewhere on our heads and head forms. The object must composed of three thermoformed parts that physically fit together in some way.
For my design, I decided to create a helmet. I was inspired by viking helmets and fighter pilot helmets, and this design is some combination of both. The main piece is the helmet, with all necessary draft and no undercuts. There will be an indexing feature by the ears to attach the horns to. Each horn will be pulled using the same mold. I thought about designing for a visor but decided that would be too complicated and it would probably not be clear anyways.
I started with three big pieces of sign foam and glued them together with epoxy. I then drew the shape of my helmet on the bottom and shaved off big chunks with the bandsaw. From there, I worked things even closer with the belt sander, and continued to work my form with a chisel and rasp and finally a file and sandpaper. To get the ridge down the middle right, I taped on some paper as a guide to keep it straight. The horn mold was fairly simple, I gave it a hexagonal pattern at the base that gradually diffused towards the end. I finished by drilling airholes to create a tighter pull and help with getting the part off of the mold. This was tough locating the holes from both sides, but I could test if they connected with the air gun.
I started the actual vacuum forming by attempting to form the horns, which I could not get out of the mold. I ended up tearing the part off the mold, and then found out that baby powder works as a mold release. I used a bunch of this, and it made a massive difference. The main helmet part I was able to get right on the first try thankfully. I cut off the excess plastic using a hacksaw and sanded it smooth.
I started painting by doing a base layer of blue and orange. This allowed me to then mask those parts that I wanted to keep, and paint the rest black. Once that was dry I pulled off all the tape and enjoyed the heck out of it. Next, glued in some foam pieces for comfort. Finally, I decided I wanted to weather the helmet, so I sanded some parts to reveal the colored paint underneath. To add on to the effect, I took some silver paint and put it on places to make it look like the paint was peeling and worn. To top it off, I dabbed some green and brown paint all over to make it dirty. I really like how it came out.
In conclusion, this project was far more challenging than I had anticipated. A lot of planning in advance goes into the design to make sure your mold is the right size and will work properly. I really enjoyed painting this thing, however. I had been wanting to try using weathering techniques on something for a while so it was a lot of fun experimenting with this, and I think it came out pretty convincing. If I were to do it again, I would probably be more careful gluing my pieces of sign foam together, since it wasn’t super tight and those lines showed up on the pulled part. All in all, it was great to learn so much about vacuum forming with this project and I’m glad that I did it.
Thanks for reading!
