Create a custom truss to place within a structural model.
A truss layout family consists of lines that define truss elements such as chords and webs. Chord and web members are created such that their center lines (local x axis) will lie along the layout lines that you define in the truss layout family. The entire layout will be transformed such that the distance between the 2 end reference planes will be determined by the truss instance based on its shape in the project.
New
Family. Navigate to the Imperial or Metric template directory and select the Structural Trusses.rft family template file. Click the Open button to open a new family file.
The structural truss family template provides 5 permanent reference planes: top, bottom, left, center and right; the left and right planes indicate the span length of the truss. Truss layout lines which end at these planes or are coincident with them will maintain this relationship during layout transformation in the project environment.
Detail panel
(Top Chord).

Detail panel
(Bottom Chord).
Detail panel
(Web).
The Length parameter may be used in your truss layout family to perform calculations to specify the exact location of vertical web members or to calculate the number of panels to create in the project environment.
Load from Library panel
(Load Framing Family).
In order to specify structural framing families for the truss layout family to use, you must load them in your truss layout family. Navigate to the Imperial or Metric family directory and select the structural framing families for chords and webs. These must be structural framing families or generic annotation families. Repeat this step to specify for each planned type of truss.
Properties panel
(Family Types). In the Family Types dialog, click New and provide a name for this truss type. Repeat this step for each planned type of this truss family.
Save As. Navigate to your family directory, provide a name for the new truss family, and click Save.
Family Editor panel
(Load into Project).