Robert Davis and Michael D'Attilio separately requested a routine to insert piping symbols with automatic trim. Many routines in textbooks and recent tips and tricks in Cadalyst insert piping symbols. However, these routines do not automatically trim the lines into which you insert the symbols. The solution presented here includes an AutoLISP file LSP), a dialog box file (DCL), a symbols library file (SLB), and a drawing file (DWG) that contains some symbols. This solution works by drawing lines in AutoCAD (figure 1) and then inserting symbols, as shown in figure 2. I am not an expert in piping symbols, so figure 2 does not make sense in an engineering application. However, it illustrates how the lines are trimmed when you insert the symbols.
How to Use PVSYMBOLS
Download the four files from the Code section of Cadalyst.com and save them in the AutoCAD Support directory. The Cadalyst Web site also explains how to load AutoLISP programs, so follow those instructions to load the PVSYMBOL. LSP file. A prompt tells you to enter PVS to start the program.
When you start the program, the dialog box in figure 3 appears. This initial dialog box shows the Air Line symbol. Notice that the selection Insert with Trim is checked. You can select any symbol from the symbols list and insert the symbol with or without trimming. When you select a symbol from the list, its picture appears at the top of the dialog box.