Please refer to the
Varkon Users Manual: mode_global, mode_local and mode_basic
Varkon Users Manual (MODULE type and attribute): LOCAL, GLOBAL, BASIC
Varkon Programmers Manual: mode_global, mode_local, mode_basic, csys_1p and csys_3p
Varkon Programmers Manual (MODULE, keywords and identifiers): Attributes LOCAL, GLOBAL, BASIC
All objects in CAD systems should be defined in named coordinate systems!
Many real objects (subassemblies/parts) are defined in local system, and
this is a good idea. A definition (local) coordinate system for an object can
optimally be chosen, the coordinates need not to be big, etc.
Unfortunately many objects are defined in a CAD system’s basic
coordinate system, i.e. the position is un-defined relative other objects
in an assembly. An import/export function (or a user must manually)
transformate the object to the right position, and there is a risk for mistakes.
With Varkon there are many options to get a good and safe handling
of coordinate systems. Many of the requirements on coordinate systems
originally came from Saab Aircraft.
Saab Aircraft defines hundreds of coordinate systems in an aircraft project. It is a tree of coordinate systems where each coordinate system (child) is defined relative a parent coordinate system.
In an assembly model can the coordinate systems first be defined and then are all the LOCAL modules (subassemblies/parts) created.
Lower level modules are normally GLOBAL. The module should inherit the active
coordinate system from its parent. Sometimes, for instance for planar sections
curves may LOCAL be a good alternative.
Very few modules shoul be (are) BASIC. Exceptions could be for some curves,
like for instance a P-value curve for a Conic Lofting Surface. This curve
shall be defined in the basic coordinate system.
When I look at all my applications I realize that I also have created very few LOCAL modules. Instead are mode_local, mode_basic and mode_global called inside the model.
Tips:
When a local coordinate system is made active (with mode_local),
immediately change back to the global (inherited, input) coordinate
system (with mode_global), when the local system system no longer is
used.
No samples for coordinate systems
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