T-FLEX Parametric CAD. Fundamentals. 2D Design

Creating Libraries of Parametric Elements
Special functions (WARN and ERROR) are provided in T-FLEX CAD for prompting the user about errors
when variables take certain inadmissible values, and request inputting different value. For example, if a nonspecified
bolt length is encountered, you can force the message: “The input bolt length is not standard”. This
is done by calling the function: WARN(“The input bolt length is not standard”).
Once the necessary variables are created, you can proceed with creating the drawing and the 3D model.
Creating Parametric Drawing and 3D Model
When using a library element is a fragment, it is often necessary to insert just a portion of the drawing.
Anticipating that, you can predefine several new layers. Use descriptive layer names to make it easy to
understand which portion of the drawing belongs to which layer. In our example, we need to create three
new layers. Let's name the layers according to their purpose: front view, left view and top view. During
creation, all elements can be placed on any layer, for example, on the layer “Main”. Once the drawing is
ready, simply select the desired portions by box and modify the layer of those elements as desired.
Some elements of the bolt (for example, the
pin hole) may or may not be displayed,
depending on the implementation. At the
previous step, we created special variables for
this purpose. The variable imp25 is equal to 0
whenever the implementation is equal to “2 -
with pin hole” or “5 - with pin hole and
groove”. In any other implementation, the
variable is equal to -10. If an element is to be
displayed only in the implementation 2 or 5,
its level must be defined by the variable
imp25.
To make sure that in the assembly drawing
the bolt is properly displayed in the bolted
joints, to each view of the drawing let us add
hidden hatches with the activated option of
suppressing the hidden lines.
Upon completing the 2D drawing, proceed
with the 3D model. Suppose, your 3D model
is required to undergo changes depending on
some parameter. It is not solely the model
dimensions that could change. Some features
may appear or disappear in the model.
In our example, such a feature is the pin hole.
The easiest way to achieve this is by
suppressing a certain operation. This can be
done using the same variables as when
defining the level of the respective features on
the drawing. What exactly can be done in this
case? The pin hole is created as follows. First,
an extrusion was made, creating a cylinder.
Next, a Boolean subtraction was done of the
cylinder from the bolt stem. The extrusion
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