This is devoted to explaining how foam is folded into intricate shapes that look like airplanes.
This page will be continually updated and revised, so if you are not finding what you should be, wait a while and it will be there. If you have a new or different way to make foam into cool shapes, please comment!
Foamboard “Anatomy”
On top: Paper
In middle: Foam like depron
On bottom: Paper
A folds and B folds
Cut through the paper and the foam but not the paper at the bottom. Move the with of the foam over (in my case 4mm) and do the same. Make sure they are parallel and go from one side of the foam to the other. Crack one of the slits open and fold it 180 degrees. peel off that long thin foam rectangle. At the end, you should have a cavity in the foam held together by the bottom layer of paper. Now to do an A fold, bring one of the sides of foam up and above another. To do a B fold, bring it up to the side of the bottom foam. This is used when creating 90 degree edges.
Foam Bends (more than 90 degrees)
Cut a groove down the foam, not cutting it through. Take something like a BBQ skewer and drag it along, pushing foam away. This can be used to make wings and have sharp edges being less than 180 degrees.
C Fold/Fold-over
Cut through the paper and the foam but not the paper at the bottom. Move 2x the with of the foam over (in my case 8mm) and do the same. Make sure they are parallel and go from one side of the foam to the other. Crack one of the slits open and fold it 180 degrees. peel off that long thin foam rectangle. BTW this rectangle should be twice as wide as the A or B folds. Then you can place the foam on one of the sides directly onto the other. This allows you to glue 2 pieces of foam together and have a smooth paper covered edge.
Crease Bending Foam (less aggressive)
Cut a groove down the foam, not cutting it through. Take a hard edge (such as a metal ruler) and bend the foam up. This can be used to make slight bends.
Wings
WingType1
WingType2
WingType3
Control Surfaces
Smooth bends
If you peel off the paper on one side of the foam, you can roll it next to a table and create a soft curve. If you have a curved piece of foam you can make it stay in the curve you want. It is useful to making realistic planes, as most airplanes are not all 90 degree corners. Although, it only really works well on larger planes, and if you have a smaller plane you should use poster board for the times you really need curves, like at the top canopy or something.
Other cool things to do with foam
Tips
Other Material Building
The LiPo Projects 