lisapinnad

Lisapinnad is an Estonian term used in technical and scientific contexts to describe additional or auxiliary surfaces that are attached to a geometric object or model. The precise meaning varies by domain, but the core idea is that lisapinnad are supplementary planar faces added beyond the primary geometry to support analysis, manufacturing, or detailing.

In geometry and computer-aided design (CAD), lisapinnad are often used to approximate complex or curved surfaces with simpler planar facets. This facilitates meshing for simulations, enables easier intersection and mating calculations, and helps define tolerances and assembly interfaces. Lisapinnad can also serve as reference faces for alignment during manufacturing or inspection.

In mechanical engineering and product design, lisapinnad commonly describe mounting, sealing, or joining surfaces that are defined separately from the main surfaces of a part. These auxiliary faces may have their own dimensions, tolerances, and surface finishes to control fit, clearance, or load transmission between components.

In architecture and construction, lisapinnad may refer to auxiliary surfaces used during the modeling or detailing phase, such as supporting planes for formwork, shading devices, or facade detailing that interacts with primary structural surfaces.

Etymology-wise, the term combines lisa (additional) with pinnad (surfaces). The concept belongs to general practices of modular modeling, tolerancing, and assembly design, with terminology and emphasis differing among disciplines.