Solid DNA blog

Blog about stuff on Solid Edge CAD software

Variables Table

At the heart of any design we can find an idea.

From that idea design intent is born

Design intent is then stripped down to rules that are reduced to simple expressions or variables.

This is where the Variables Table takes its meaning

In this article I will introduce in an in depth way this essential tool needed to create a parametric model.

table-des-variables_01

Types of variables

Two types of variables can be found

  • Dimension (Dim)
  • Variables (Var)

Type of variables – Dimensions

Dimensions are created when users place dimensions inside a sketch. To help identify them, in the column “Type” you will see the “DIM” mention. This indicates value is extract from the 3D model.

Note: PMI (Product Manufacturing Information) also creates DIM entry in the table. Later in the article I will show how to filter those variables.

Type of variables – Variables

Variables can be created by the system or by the user. To help identify them in the column “Type” you will see the “VAR” mention.

When the system creates variables, this has a direct impact on the morphology of the model.

When users create variables, no direct impact on the morphology of the model can be seen unless you link to geometry through a formula.

Exemple of user VAR

Pi=3.14159

By making combinations of Dimensions and Variables you can define rules that will manage the design intent

  • Control a dimension with another dimension (Dimension A = Dimension B).
  • Define a variable (pi=3.14).
  • Control a dimension with a formula (Dimension A = pi * 3.5).
  • Control a dimension with a formula and another dimension (Dimension A = pi * Dimension B).
  • Control a dimension with a formula that includes a function (Dimension A = Dimension B + cos(Dimension C)).
  • Control a dimension with a value from a spreadsheet, such as a Microsoft Excel document, by copying the value from the spreadsheet into the Variable Table with the Paste Link command. You can use any spreadsheet software that can link or embed objects.

Note: Excel can be used but I recommend you avoid externalizing information for better management and interaction etc…

Variables units

When dimensions ( variables) are extracted from the 3D model, unit is automatically defined by the system.

On the other hand a “Var” created by a user needs to have its unit defined.

Here is the list of unit types available, sorry for this one my french readers got the lead J

Distance Fréquence
Angle Capacité calorifique
Masse Flux de chaleur par unité de surface
Heure Flux de chaleur par unité de distance
Température Source de chaleur
Charge électrique Éclairement
   
Intensité lumineuse Accélération linéaire
Quantité de matière Linéaire par angulaire
Angle solide vitesse linéaire
Accélération angulaire Flux lumineux
Moment angulaire Force magnétique
   
vitesse angulaire Flux magnétique
Surface Densité du flux magnétique
Force mécanique Taux du débit de masse
Coefficient de dilatation Moment d’inertie de masse
Densité Masse par unité de surface
Capacitance électrique Masse par unité de longueur
   
Conductance électrique Moment
Force du champ électrique Proportionnel à la distance
Induction électrique Puissance
Différence de potentiel électrique Quantité d’électricité
Résistance électrique Intensité du rayonnement
   
Énergie Rigidité de rotation
Entropie Second moment de surface
Coefficient de film Conductivité thermique
Force viscosité dynamique
Force par unité de surface viscosité cinématique
Force par unité de distance Volume
Taux de débit volumétrique
Scalaire (sans unité)

To define the “Variable” unit, use the drop down menu at the top left.

table-des-variables_02

Filter Variables

On the right of the drop down menu for units, click the small funnel icon.

The Funnel tool helps filter what is visible inside the table.

table-des-variables_03

Filter – Type

Users choose the type of variable that will be visible.

  • Dimensions
  • User Variables
  • PMI Dimensions

Note: In traditional modeling PMI data helps create reference information for the manufacturing. Since they are references, the background of those cells will be gray out.

Filter – Named by

Each new entry in the table gets a default name by the system or one defined by the user at the creation of the “VAR”.

At anytime the user can redefine the name to ease the management of the entry in the table.

As a rule of thumb you should rename only the variables that you change frequently. This way you will be able to create some kind of form by filtering the table. The column “Description” could also be use to add an extra level of filtering.

  • Users – Display only variables named by the user
  • System – Display only the variables who do not need to be renamed ( they have their original system name)
  • Both – Both are displayed

Note: To have a variable return to its initial name, simply delete the content then press ENTER

Filter – Graphic In

Allow filter variables base on:

  • Last Selected Window – Displays variables that are associated with elements in the active window.
  • Select Set – Displays variables that are associated with elements in a group that you have selected in the document.
  • File – Displays variables that are associated with elements in the current document.

Formula

On the right side of the filter button, the formula button guides users to establish basic formulas.

table-des-variables_04

One example, is the formula that can be write to round off to the 16th.

table-des-variables_09

Figure 1 – Decimal display

table-des-variables_10

Figure 2 – Fraction display

Formula – Round off Rules

Solid Edge offers two ways to round value. (This feature is associated to dimensions placed inside sketches not directly in the table)

  • First round off is base on the rule of .5. This one round off to the upper value (.625 = .63 / .635 = .64)
  • Second round off is base on the odd value. (.625 = .62 / .635 = .64).

This second rule has the advantage to distribute the round either up or down. This is the default use in Solid Edge.

For each Dim user has the choice between the two. ( RMB click on a dimension inside a sketch then choose properties)

table-des-variables_11

Variable rule editor

For each variable, users can decide what rule will be enforced to establish the range of the variable value.

table-des-variables_05

Variable rule editor – Value base on

Here users define how the variable will be fed:

  • Base on a formula (Formula can be any algebraic equation)
  • Base on a link

Link is comparable to what can we found in Excel. The link can be established between two cells of the same table. If a link is established between two parts/assemblies/drafts this workflow is called Peer Variable.

Variable rule editor – Limit value to

Users can limit the value of a variable to a range of value. Two choices are offered

  • Discrete list ( 20;30;35;45)
  • Minimum/Maximum value

Minimum and maximum value can be set based on:

  • Maximum/minimum or equal
  • Maximum/minimum
  • No maximum/minimum

Column

table-des-variables_06

The Columns help manage the data inside the table. Users can double click on the column header to sort values.

Columns can be reordered by simply drag’n dropping the header

With the RMB a contextual menu can be accessed with regular windows features like:

table-des-variables_071

Column – Expose

See previous article

Variables exposées en tant que propriétés personnalisées.

Video for this article shows the exposed functionality.

Cell

Cell with a gray background indicates it cannot be edited directly. Most of the time those cells refer to a reference value or the value is pushed by an external formula.

A contextual menu is available for each cell of the table.

table-des-variables_08

Cell – Peer variable

Previously I talked about establishing a relation between two cells. Here is a quick instruction:

  • From the source table, highlight the line then from the contextual menu click « Copy link ».
  • In the destination table, highlight the destination line then from the contextual menu click « paste link ».

Video for this article show the expose functionality.

Manipulate the table

So far we have seen the process that runs inside the variable table, what’s left is to take a look at the technicals inside the context of a modeling project.

What can be better than doing so through an interactive tutorial?

Variables Interactive tutorials

Conclusion

A variable table is more than just a table to store numbers; it is the brain behind your design.

1 Comment »

  1. […] kind of SolidWorks’ Instant3D or what is call inside Solid Edge Dynamic edit/direct editing ( peer variables can be use for assembly). This may come with a litle extra has feature could eventually be […]

    Pingback by Inventor fusion or AutoCAD revisit? follow-up « Solid DNA blog | 2 November 2009 | Reply


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