Creating a Shape Code 99
When detailing with Probar2D in AutoCAD® and a rebar shape code is required that’s not included in the current shape code list the Shape Code Editor, included in Probar2D, can be used to define a shape code 99.
The Shape Code Editor consists of two main areas namely the bar size and shape code definitions. The bar size definitions are where the rebar grades, available diameters and nominal allowances for hooks and bends are defined. The shape code definitions are where the rebar shape codes are entered. To access the Shape Code Editor, follow the steps:
- Open the Add Bar window
- Click the Calculator button and
- Then on the Edit Mode button
Rebar shape codes are stored as a comma delimited text file (.txt). The relevant shape code lists are grouped within the different localization folders located in C:\Prokon\Probar2D. For example, SANS 282 2004.txt and SANS 282 2011.txt is stored in the South African Shape Code lists folder.
When entering a new shape code, the following three (3) input tables will be used, as indicated in Figure 1:
- Nodes: This table defines the coordinates of the nodes of the rebar, i.e., start and end points, and bend locations.
- Vector list: Defines how AutoCAD® will stretch the bar in relation to the bar dimensions.
- Dimension list: For each bar dimension. The default value is specified when starting to draw the rebar shape code. The minimum allowed and maximum allowed dimension are in millimeters.
Note: You can also set a dimension to be redundant, i.e., the dimension value is determined by using a specified cutting length and then bending the bar into the particular shape.
Suggested steps for defining a new rebar shape code:
- Draw the shape code on paper. Assign the bar dimensions A through E to various parts of the shape.
Note: Dimensions can be assigned along the length of a bar segment, or as a vertical or horizontal projection.
- Enter a new shape code number, this may be alphanumeric, thereafter click Add New SC.
- In the Dimension list, enter default values for the dimensions for A through E. The default values that are assigned can be a physical dimension in millimeter or a factor of the bar diameter, e.g., “12*dia”.
Note: If the shape does not use a dimension, for example dimensions A through D is assigned but there is no dimension E, set the dimension’s value to zero.
- In the Nodes table:
- Enter the X and Y coordinates of the bar nodes in terms of its dimensions A through E. Choose an arbitrary origin (0,0) — it is easiest to choose one of the bar nodes to coincide with the origin. Furthermore, when entering the X and Y coordinates for each node, formula can be used. Namely, +, -, * and /, sin, cos, and tan, as well as ^ to raise to the power. References of the bar coordinates A through E as well as die bar diameter “dia” and nominal length “N” can be used as well.
- In the Node code column, enter “0” for a start or end node, “f” for a fillet (bend) between the adjoining straight segments, or “h” for a hook at the start or end node.
- For bar segments that are curved between nodes, enter a bulge value.
- The new shape code should visually resemble the desired shape. Complete the definition by entering the Vector list— this will define the grips that AutoCAD® will use for stretching the shape code in relation to the dimensions A through E. Assign “L” to a dimension in the Code column for a parallel vector or limit it in the X and Y directions by assigning an “X” or “Y” respectively.
Note: Never start with a vertical length when creating a custom shape code.