I'm a student at the West-Flanders High School (HOWEST). I study industrial product design and for one of our projects we had to make a flat packed product. The conditions imposed on our flat packed product are:
- Finding a creative solution to create a volume out of a sheet material.
- Apply the flat pack technique on products that aren't obvious to be flat
packed.

First of all I want to say that the helmet using the materials described in this instructable is a proof of concept therefore it isn't safe to use it in real life situations. The objective of the proof of concept is to demonstrate, using simple materials like cardboard, textile, Velcro and Styrofoam, that you can make a bike helmet flat pack. Actual production of this helmet would require using leather instead of a cheap textile, ABS instead of cardboard and of course the helmet would be fitted with a buckle strap.

This helmet is targeted to people who go to work or school and want minimum protection. These people don't wear regularly their helmet because they can't get rid of it during the day. The advantage of this helmet is that you can store it in your bag.

Let's make it!

Step 1: What Do You Need?

The tools you will need are:
- superglue
- scissors
- cutter
- chalk
- ruler

The materials you will need are:
- cardboard (without waves)
- textile (it has to be flexible)
- Velcro
- styrofoam

Step 2: Measurements

First we will cut the unfolded shape of the helmet out of the textile using the chalk to draw the shape on the textile and also some scissors of course. In attachment you will find one Illustrator file with all the measurements of the unfolded shape and the other file is the unfolded shape without measurements. If you print this last file you can draw with the chalk around the printed shape. This makes life easier. After drawing the shape you cut it out with your scissors.

Step 3: Cutting the Figures

Now you'll cut out all the triangles out of the cardboard with the cutter. Again I have put in attachment all the measurements of each figure you will need then 3 other files with the same figures but in large numbers (enough to fill the entire helmet plus some figures in reserve) so you will save time to cut out all the triangles. When you are finished cutting the triangles it is good to put the different triangles in a separate box so you wont lose track of them.

Step 4: Gluing the Figures

Next you will glue the figures on the textile using the superglue. I found it useful to draw the lines/spaces between the triangles so I can see exactly where I have to glue my triangle. This is important because the triangles allow the textile to fold on the desired place but for this all the triangles have to be glued roughly on the same place on each unfolded part.

Step 5: Gluing the Velcro

Gluing the Velcro is very simple. On each unfolded you should have a zone that is still free (no triangles are glued here). This zone will be used to glue the Velcro on it is 1cm large. If the tape on the Velcro doesn't stick really well then you can always make use of the superglue. You don't have to cover the entire zone. On the back you glue the other part of the Velcro. Now you can stick all the Velcro's together and create a 3 dimensional form.

Step 6: Cutting the Styrofoam

On the picture here above you can see which zone the Styrofoam has to cover. Very important leave two opposite sides free of Styrofoam because these will be use to attach the buckle straps on. One piece has to be smaller because you still have to be able to fold the textile. These two pieces of Styrofoam you have to make four of each piece. You cut them with your cutter out of the 1cm thick Styrofoam plate. Then you attach pieces of Velcro on the right place on the textile (if you want to do it properly you put the Velcro in the centre of the zone marked in red on the picture above) and the other Velcro part you stick at the back of all eight Styrofoam pieces.

Step 7: The Buckle

You should have two opposite sides that don't have Styrofoam on it. These sides will be used to attach a buckle on it. I just used a Velcro strap because this isn't the part I want to prove in my concept. I suggest strongly a buckle strap if you want to use the helmet in real life and it is best to knit the buckle straps instead of gluing them on the textile.

You attach the buckles in the centre of each side. In my example this is a simple Velcro piece you stick at the centre of each piece.
Now you are finished!

Step 8: Better Materials

For those who want to use this helmet in real life. I suggest you use leather instead of a cheap textile because it is really good against heat/friction and instead of using cardboard you can use ABS this will serve as a solid shell that will protect you from sharp objects and it will offer the first protection against impacts. Of course strap buckles are obligatory when you use the helmet in real life. The Styrofoam can be used also in the definitive product because it is used in all helmets and will protect you from big impacts.
This helmet doesn't contain a large number of Styrofoam plates so it will not be the most safe helmet but the helmet is targeted for people who go to work or school and want minimum protection. These people don't wear regularly there helmet because they can't get rid of the helmet during the day this concept has the advantage that you can store the helmet in your bag and you won't have to carry the helmet the entire day in your hand.