## On-the-fly and stock parts

1.  On-the-fly parts require ports that can be modified by the user after placement. The second tutorial, see above, shows how to create a piping instrument with these ports by adding a new subnode to the **Custom Instruments** or **Custom Specialties** node.

![](./media/image70.png)

2.  All **non**-on-the-fly parts, that is, stock parts, must be exported by selecting the **Piping** node directly. This applies to typical spec parts, operators, clamps, stock instrument class data, and stock piping speciality class data. See, for example, the existing data in the `InstrumentClassData` and `PipingSpecialtyClassData` sheets.

![](./media/image71.png)

> You must adapt the generated bulkload workbook after export from **3D SymbolDesigner**. For example, `PipeComponentClass` must be replaced with `SpecialtyClass` in the header of the part class sheet.