Synchronous Technology (NX)

🔗 Related Concepts

Deepen your understanding with these related topics:

Definition

Synchronous Technology (ST) operates on solid geometry through face-level commands: Move Face, Pull Face, Resize Face, Make Coplanar, Make Perpendicular, Modify with Rules. It works on both native parametric geometry (where it adds a Synchronous feature step to the timeline) and imported direct geometry (where there's no parametric history to disturb).

ST infers design intent through rules (e.g., 'this face was perpendicular to that face — preserve that') and applies the edit while respecting inferred constraints.

Why it matters

ST is NX's competitive moat. Mixing parametric and direct in one platform without losing data is uniquely NX. For imported geometry, ST is the only practical way to make significant edits.

Technical Deep Dive & Core Mechanics

Surface modeling operations in Synchronous Technology (NX) create open-body geometry (surfaces without enclosed volume) using NURBS mathematics. Each surface is defined by a control-point grid, knot vectors in U and V directions, and a polynomial degree. The surface passes near (not through) the control points, with the degree determining how smoothly the surface responds to control-point adjustments. Higher-degree surfaces (degree 5 or above) offer more curvature continuity but increase computational cost for intersection and projection operations.

When Synchronous Technology (NX) involves trimming a surface against another (e.g., creating a fillet between two faces), the kernel computes the intersection curve—a computationally expensive operation that involves solving systems of polynomial equations. The resulting trim curve divides each surface into "used" and "unused" regions. Trim-curve accuracy affects downstream operations: poor trim tolerances cause gap or overlap errors at face boundaries, which become visible as "stitching" failures when attempting to convert open surfaces into a closed solid for Synchronous Technology (NX) downstream operations like shelling or Boolean subtraction.

Step-by-Step Professional Implementation

Deploying Synchronous Technology (NX) in a mechanical or product-design production pipeline requires stable modeling discipline and data management:

1. Set Up the Part/Assembly Template: Start from a company-standard template that pre-configures units, material libraries, default tolerances, and drawing sheet formats. Ensure the design intent is captured through a clean feature tree from the first sketch.
2. Apply Parametric Constraints Methodically: When building Synchronous Technology (NX), constrain sketches fully before extruding. Reference stable datum planes and origin geometry rather than edge references that may shift during design changes (avoiding dangling references).
3. Enrich Metadata for Manufacturing: Populate custom properties (material, finish, heat treatment, part number) in the model's iProperties, custom attributes, or parameters. These feed directly into BOMs, PDM systems, and ERP integrations.
4. Validate and Release: Run interference detection on assemblies, verify mass properties, and check for rebuild errors or suppressed features. Pass the model through your PDM/PLM check-in workflow with appropriate revision and lifecycle state updates.

Advanced Troubleshooting & Error Diagnostics

Troubleshooting workflow for Synchronous Technology (NX) in PDM-managed parametric CAD environments:

• External references lost after file rename or move: Opening an assembly after reorganizing the file structure causes Synchronous Technology (NX) components to show as missing. Resolution: Use the PDM system's rename/move functions instead of operating-system file operations—PDM tools update all internal reference paths. If references are already broken, use the assembly's file reference dialog to manually remap each missing component to its new location.
• Mass properties incorrect for multibody parts: The mass calculation for Synchronous Technology (NX) doesn't match expected values. Resolution: Verify that material assignments are applied to each body in multibody parts (some systems require per-body material rather than per-part). Check for suppressed features that remove material. Confirm the measurement units match expectations (the mass properties dialog may display in different units than the part's modeling units).
• Drawing views don't update after model change: Section views or detail views of Synchronous Technology (NX) show stale geometry after modifying the parent model. Resolution: Force a drawing update (Ctrl+Q or equivalent rebuild command). If specific views lag, check for broken view references—views that reference deleted features or configurations may freeze at their last valid state rather than updating.

Cross-Discipline Collaboration & Handoff

In multi-discipline product development, Synchronous Technology (NX) must integrate smoothly with downstream manufacturing, simulation, and documentation workflows:

• Neutral Format Exchange: Export to STEP AP214/AP242 for maximum fidelity when sharing with partners who use different CAD platforms. Validate that feature topology, PMI (tolerances, datums, surface finish), and assembly structure survive the translation. Avoid relying on native formats for external suppliers.
• PDM/PLM Integration: Check in models through the product data management system with complete metadata (revision, lifecycle state, effectivity). Ensure that the BOM structure visible in the PLM matches the CAD assembly hierarchy, and that released parts are locked from unauthorized edits.
• Simulation and Manufacturing Handoff: Provide defeatured geometry to FEA analysts (remove cosmetic rounds, simplify internal cavities) and manufacturing-ready geometry to CAM programmers (with GD&T annotations). Coordinate on material specifications and tolerance stack-ups across the design-to-production chain.

Common pitfalls

• Heavy ST use on parts with long parametric history — history becomes misleading.
• Relying on rule inference for edits that should be explicit dimensional changes.
• Mixing ST and pure parametric features without a discipline for which is which.

Relevant Siemens NX FAQs

Direct answers from our technical editorial desk concerning related workflows.

🎓 Recommended Practice Lessons

Step-by-step practical exercises and certification-aligned paths chosen by our editors to master this concept:

Practical Workflow Tips

Practical experience with Synchronous Technology (NX) in production parametric CAD environments:

• Keep feature count low: Fewer features means faster rebuilds and fewer reference failures. Combine operations where possible—a single multi-contour extrude is more stable than several separate ones.
• Test with extreme parameters: After building a parametric model, drive dimensions to minimum and maximum values to verify the model rebuilds correctly across the full range.
• Simplify for downstream use: Before sharing Synchronous Technology (NX) geometry with FEA or CAM teams, remove cosmetic features that add complexity without affecting the downstream task.
• Write meaningful PDM revision descriptions: "Updated per review" tells the next person nothing; "Increased wall thickness from 2mm to 3mm per stress analysis results (ECN-4521)" provides traceable context.

Sources & further reading

• Siemens Digital Industries Software Support portal · Siemens AG