T-FLEX Parametric CAD. Fundamentals. 2D Design

Basic Fundamentals and Concepts of Working with Assemblies
A fragment that contains nested fragments is exploded into the graphic elements and fragments that it
contains. After using the exploding option, the obtained elements can be treated as usual, according to the
type.
If some elements in the assembly drawing were attached to fragment elements (dimensions, construction
lines, etc.), then, upon exploding, those will be re-attached to the elements created by the fragment explosion
(nodes, construction and graphic lines).
Use of Connectors
When creating assembly documents, it is often necessary to relate parameters (variables) of the inserted
elements with the parameters of the elements to which the attachment is made. Examples are: setting a ball
bearing on a shaft, attaching a cap to a ball bearing, a shaft key to its slot, a nut to a bolt, insertion of a screw
or being into a hole, etc. When inserting such elements, the user is required not only to define the main
dimension parameters (diameter, length, etc.), but also precisely position the elements being inserted with
respect to the target element (selection of the attachment point and direction). One of the ways of solving this
task is using “Measuring” mechanism. This mechanism, however, often requires large amount of auxiliary
preparations. Connector mechanism helps significantly simplify the procedure of assembling elements and
minimize the number of actions required from the user.
This mechanism is based on the concept of a “connector”
which is a construction element serving as a reference for
attaching other elements. In fact, a connector is a
counterpart of a fixing vector or a target LCS for attaching
3D fragments. Its main difference from a fixing vector is
that a connector serves for providing attachment reference
to other model elements. Consider, for instance, use of a
fixing vector for inserting a bearing image into an
assembly drawing. Suppose, the image of the bearing
should be attached to an axle. In this case, the connector
should be attached to the axle image (fragment).
Besides the geometrical positioning (the origin position
and the axes directions), a connector may keep additional
information necessary for “snapping” to it other elements.
This information is kept in the connector in the form of named values that can be constants or variables. The
names of these values are used for specifying the values of the respective external variables of the fragments
being snapped to the connector. For example, a connector placed on the axis of a hole, can have such
parameters as the hole depth and the diameter. When inserting a pin in this hole, its diameter can be
automatically defined by the value D kept in the connector. To achieve this, the external variable defining the
in diameter should also be named “D”.
There are a number of considerations when using a connector for snapping a fragment:
• A connector is a construction entity and may not be displayed in the main drawing, while it has to be
selected when snapping a fragment to it.
• A connector may be located outside the viewable area of the drawing.
• Sometimes, it is convenient to use a connector for placing an element elsewhere. For example, when
attaching a cap to a ball bearing, it is convenient to select the outer lines of the ball bearing.
Meanwhile, the intended connector is lying on the ball bearing axis.
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