T-FLEX Parametric CAD. Fundamentals. 2D Design

Fundamentals. Two-Dimensional Design
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The same operations can be carried out in the dialog window of the command “V: Edit Variables”:
Keyboard Textual Menu Icon
«Parameters|Variables»
Similarly, define a variable “H” as the distance from the base line to the top side of the main view. Select the
line on the drawing by clicking and enter the variable name in the property window. Now there will be
already two variables in the window “Variables”, and you can, by modifying their values, observe the change
in the drawing.
Try making an expression. In the window “Variables” place the cursor in the field “Expression” of the
variable «H» and press to enter the edit mode. Specify the expression «W/2» instead of the numerical
value. This means that the value of “H” will be equal to the half of “W”. From now on, changing just the
value of “W” will automatically reflect on the value of “H”.
Next, let’s assign an “R” variable to the radius of the circle defining the fillet at the upper-right corner of the
plate. Select the circle on the drawing by . In the property window specify the radius as “R” variable.
After confirming its creation, in the window “Variables” set the variable to the following expression: W <
100 ? 0 : 6
This expression means that “R” equals 0 when “W” is less than 100, and equals 6 otherwise.
Let’s briefly explain the syntax of the expression. Its members are described as follows.
< - is the “less than” sign
? - means “then”, “in such a case”
: - means “else”, “otherwise”
The complete expression is written as
R = W < 100 ? 0 : 6
The value of “R” equals 0, if “W” < 100, and equals 6 for any other value of “W”. Therefore, there are only
two possible values of “R” - either “0” or “6”.
Check this on your drawing. Try setting “W” values greater or less than 100, and watch what’s happening.
Note that when the radius of the fillet equals 0, then the radial dimension automatically disappears. The
system does it for the user.
Therefore, one can create a variety of relations between variables, including quite complex ones, using just a
few basic terms. You will get to know all capabilities of the variables functionality in later chapters.
Creating Sketch, Non-parametric Drawing
We will use the same familiar drawing example of the plate with a conical hole. Let’s begin with
constructing the main view. Thereafter, we will create two projections, the “Left Side View” and the “Plan
View”, using object snapping mechanism.
In this case, all construction is done using the command “SK: Create Sketch”. Call the command via
Keyboard Textual Menu Icon
«Draw|Sketch»