Abstract: A machine suitable for fabricating a core material of resinated filaments has a frame having attachment points for filaments arranged linearly and a number of rods spaced apart and substantially parallel to the attachment points. The rods have one or more holes capable of receving a filament, and the rods are capable of displacement parallel to the plane of the attachment points. There is also a filament supply for passing filament from the attachment points via the rods, and a set of formers having pins capable of being located between the separated filaments following displacement by the rods. By operation of the machine and successive insertion of former, a shaped openwork structure of resinated filaments may be fabricated and which may be cured to produce the core material.