NX Routing Mechanical: Practitioner Workflow Notes

Notes distilled from a CAD-training consultancy's practitioner write-up on NX Routing Mechanical (piping/tubing/HVAC), covering setup and day-to-day workflow habits that official docs tend to mention only in passing. (Source: NX Routing Mechanical Notes – Part 1, Swoosh Technologies)

Units and discipline setup

• NX Routing ships with metric as the default unit system, and more out-of-the-box library content is available for metric assemblies than for imperial/English units — a real consideration for US-based shops standardizing on inch parts.
• Unit system switching is controlled through the ugii_env_ug.dat configuration file by commenting/uncommenting the relevant environment variables — this is an admin-level, not per-session, setting.
• Routing Preferences determine which parts and stock the library exposes for a given session, and the active discipline (piping, tubing, or HVAC) can be switched at any time mid-session without starting over.

Use routing-specific commands, not generic assembly commands

This is the single most emphasized workflow habit in the notes: always use the Routing-specific equivalents of assembly operations, because they preserve routing intelligence that generic assembly commands silently discard:

• "Place Part" instead of Assemblies → Add Component — leverages ports and anchoring so the part snaps into the route correctly.
• "Replace Part" — maintains existing connections and triggers design-rule checking automatically; a generic component replace would not.
• "Move Part" — repositions using port-based logic rather than raw XYZ transforms.
• "Remove Part" instead of Edit → Delete — deleting a routing part the generic way can leave the segment subdivided/orphaned instead of cleanly healing the route.

Standard assembly sequencing

The recommended sequence is: generate the paths first, then add stock, then add qualified parts onto the stock/paths. Doing this out of order (e.g., dropping qualified parts before a path exists) is a common source of confusion for new users.

Key routing-specific objects to understand

• Routing Control Points (RCPs): the intelligent connection points where segments join. They control the location and orientation of adjoining elements, and operations like "Assign Corner" (for bend editing) depend on which RCP is selected.
• Ports: every routable part needs ports defined in order for automatic placement solutions and positioning options to work at all. Parts without properly defined ports won't behave predictably in the router.
• Run Navigator: used to organize manually-defined, fabricatable subassemblies so large routed systems stay manageable rather than becoming one monolithic structure.

Legacy stock vs. component stock

Stock defaults to legacy mode (a swept feature, not a discrete component). The "Convert to stock as components" command turns this into true assembly components instead. The notes flag this as a decision that is "best made at corporate policy level, not individually" — i.e., don't let individual designers choose per-project, because mixed conventions across a design set make library maintenance and BOM extraction inconsistent.

Practical implication for a new routing rollout

Taken together, these notes argue for writing a short internal "how we route in NX" cheat sheet before turning designers loose: pin down the unit system, mandate routing-specific commands over generic assembly commands, fix path→stock→parts sequencing as the house standard, and decide legacy-vs-component stock once, centrally.