How do I add a new rebar shape code?
AutoPadds stores the definitions of rebar shape codes in a comma delimited text file in the Prokon\AutoPadds folder. The default definition file is called SC_List.txt.
To edit, add or delete shape codes, use the Edit Shape Codes command to display the Shape Code Editor. The Shape Code Editor has two main areas:
- Bar size definitions: For defining rebar grades, available diameters and nominal allowances for hooks and bends.
- Shape code definitions: This is where you will be entering rebar shape codes. The rest of this article focuses on using this part of the Shape Code Editor.
When entering shape codes, you will use three input tables:
- 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, specify the default (when starting to draw it), minimum allowed and maximum allowed dimension in millimeters. 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.
Using the Shape Code Editor may seem a bit daunting at first. By examining some of the predefined shape codes together with the suggested steps below, you should soon understand the logic.
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. A dimensions can be assigned along the length (parallel) of a bar segment, or as a vertical or horizontal projection.
- Enter the new shape code number (may be alphanumeric) and click Add New SC.
- In the dimension list, enter default values for the dimensions for A through E. If the shape does not use a dimension, e.g. A through D and no E, set the dimension's value to zero. The default values that you assign can be physical dimensions in millimeter or a factor of bar diameter, e.g. "12*dia".
- In the nodes table, enter the X and Y coordinates of the bar nodes in terms of its dimensions A through E. In doing this, you will need choose an arbitrary origin (X=0 and Y=0) — it is usually easiest to choose one of the nodes to lie at the origin. When entering the X and Y coordinates for each node, you can use formula (use +, -, * and /, sin, cos and tan, as well as ^ to raise to the power) that references the bar coordinates A through E as well as die bar diameter ("dia") and nominal length ("N"). 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 (similar to a bulge for a polyline). At the starting and ending nodes, you can also specify a fillet.
- You should see a recognizable drawing of your new shape code by now. 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. You can enter a vector parallel to a dimension ("L") or limit it in the X and Y directions only.