Origami Heaven

A paperfolding paradise

The website of writer and paperfolding designer David Mitchell

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Modules and Modular Families
 
Modules are geometrical paperfolds which can be combined into modular assemblies. Most modules are folded from a single sheet of paper but it is also possible to design compound modules which are folded from several.

Threre are a huge variety of designs for modules, many of which are derived from each other, or are sufficiently similar in folding method and structure that they can be grouped into modular families. There are, of course, singleton modules as well.

Like real families, modular families are seldom clearly defined and tend to merge into each other and overlap (so that a module may belong to several modular families rather than just one). For this reason a definitive analysis of modules into families probably cannot be made.

Nevertheless, it seems to me that the concept of modular families is a useful one. Here are some of the main modular families you are likely to encounter.

 
  Edge-pocket modules

As the name suggests edge-pocket modules are characterised by the position of their pockets at the edges of the module. The picture to the left shows one of the modules for my Simplex Cube with arrows indicating the pockets.

 
Centre- pocket modules

Similarly centre-pocket modules have pockets in the centre of the module. The picture to the right shows one of my Letterbox modules with arrows indicating the pockets. The basic Sonobe module would fall into this modular family, although the central pockets of that module are aligned diagonally rather than parallel to the edges as here.

 
 
  Corner-pocket modules

The picture here shows a corner-pocket Sonobe module with arrows indicating the pockets. A corner pocket is created by turning a corner (shown by the dotted lines) inside out between the other layers. The corner-pocket modular family probably has more members than any other family.

 
Delta modules

Members of the edge-pocket, centre-pocket and corner-pocket families tend to have two tabs and pockets arranged alternately around the module. In delta modules the pockets are adjacent to each other, This tends to give the module a triangular form, hence their name.

 
 
  Butterfly modules

This is my name for the family of very simple modules that sef-integrate by means of compact weaves, among which are, of course, the waterbomb base and its converse, the preliminary fold. Many of these modules and designs are explained in my book Building with Butterflies.