Autodesk Inventor Assembly, Content Center, Piping and Harness

Overview

An Inventor assembly (.iam) is the space where part-to-part relationships (Constraints and Joints) and hierarchical structure (Sub-Assemblies) are handled. Layer in Content Center's standard part libraries, Tube & Pipe piping, and the Cable & Harness electrical harness module, and you have most of the building blocks required for large equipment design.

1. Constraint vs Joint

Introduced in Inventor 2014, a Joint (mechanical joint) bundles multiple Assembly Constraints into a single definition. Because it handles degrees of freedom explicitly, the solver is faster and management is simpler.

The general rule: prefer Joints whenever possible. That said, Constraints can be more intuitive when you need to Mate/Flush several faces at once.

Constraint Types

• Mate: face-to-face coincidence (Flush option aligns them in the same direction)
• Angle: angle
• Tangent: tangency
• Insert: cylindrical axis alignment + face mate simultaneously (ideal for bolting)
• Symmetry: symmetric about a reference plane

Joint Types

• Rigid: fixed (DOF 0)
• Rotational: single-axis rotation (hinge, shaft)
• Slider: single-axis translation (linear guide)
• Cylindrical: coaxial rotation + translation (piston / rotation)
• Planar: translation on a plane + rotation
• Ball: 3-axis rotation (spherical joint)

2. Sub-Assembly Strategy

• Group by function: Parts that move together belong in one Sub-Assembly. Examples: cylinder + piston, motor + gearbox.
• Flexible Sub-Assembly: Internal Constraints/Joints of the sub can be driven from the parent. Toggle Flexible ON/OFF to tune performance.
• Grounded Part required: Every Sub-Assembly must contain at least one Grounded Part. Without one, it has no reference point and "floats".

3. Adaptive

A relationship where a part's size or position is determined by another part. Example: a pin whose length stretches to match a hole's depth.

4. Contact Solver

Simulates physical contact. Menu path: Inspect → Activate Contact Solver.

• Prevents interference during real-time motion (gear / cam drive checks)
• Always specify a Contact Set. Targeting the whole assembly without one makes the solver extremely slow
• For simple gear linkages, Motion Constraints (Rack & Pinion, etc.) are overwhelmingly faster

5. Large Assembly Performance

Inventor's strength lies in equipment design with thousands of parts, and it has rich options for tuning "how to open it and how to display it".

• Express Mode: Read-only for large assemblies. No editing, but Open speed improves several-fold to tenfold
• Level of Detail (LOD): Assembly Representations. Define Master / Primary / All Suppressed / Custom
• Suppressing unnecessary subs in a Custom LOD dramatically speeds up open and computation
• Visibility Only: Simple hide still consumes memory. If you're after performance, choose Suppress or LOD
• Design View Representation (DVR): Saves view, color, and zoom state. Can be linked to Drawing views
• Position Representation: Saves different mechanism poses (open/closed, etc.)

→ See also: /cad-tips/inventor/ilogic-vault-troubleshoot (Shrinkwrap, Simplify)

6. Content Center

Inventor's built-in standard part library. It holds tens of thousands of parts in ANSI, ISO, DIN, JIS, and GB standards — bolts, nuts, washers, bearings, profiles, and more.

Enabling

• Check only the libraries you use in Inventor Options → Content Center
• Specify the Content Center Files path in the project (.ipj)
• Vault integration: All users share the same CC libraries

Place from Content Center

Menu path: Assemble → Place → Place from Content Center.

• Search parts in the category tree
• As Standard: Reference only from the shared library (non-editable)
• As Custom: Create a copy. Can be saved with the in-house Part Number and edited

Family Table

Manages size variations of a single part as a spreadsheet. Similar to iPart, but with a Content Center-specific structure.

• Key Columns: Up to 8. Criteria for search and filter (e.g., Size M6, M8)
• Boolean columns: Control feature visibility / suppression
• iProperty mapping: Automatically assigns Part Number, Mass, and Material per row
• Edit via Spreadsheet: Export to Excel for bulk editing → changes apply on save

Adding Custom CC Parts

1. Open the IPT → Manage → Author → Content Center Part
2. Configure template properties (category and parameter mapping)
3. Publish Part → pick the target library
4. With an iPart Factory, multiple members can be published at once

Field Recommendations

• Read-Only libraries: Company-standard libraries should be Read-Only for all users. Only admins can publish
• Separate user libraries: Put project-specific CC parts in a separate library to keep search fast
• Uncheck Unused: Always uncheck libraries you don't use. Major impact on overall performance

7. Tube & Pipe (Piping)

Inventor Professional-only module. Supports three categories: Rigid Pipe, Bent Tube, and Flexible Hose.

Workflow

1. Create Pipe Run: Generate a Run Sub-Assembly inside the assembly (Design → Tube & Pipe → Create Pipe Run)
2. Select a Style: Rigid Welded / Bent Tubing / Flexible Hose, etc. Material and size Styles must be defined in advance
3. Create the Route: Auto Route (automatic between two points), Sketch Route (based on a 3D Sketch), Derived Route (from an existing sketch)
4. Populate: Auto-places fittings and pipes along the path
5. AutoDrop: Drag a fitting from Content Center → auto-snaps onto the route

Pipe Style Management

Menu path: Design → Tube & Pipe → Styles → Tube & Pipe Styles.

• Pipe: Size, Material, Schedule
• Fitting: Elbow (90°, 45°), tee, coupler, reducer, flange
• Connection Type: Welded / Threaded / Socket / Flanged
• Bend Radius Rule: Minimum / maximum radius for bent tubing
• Round-off Increment: Pipe length rounding unit (field cut tolerance)

Auto Route Tips

• Node Points: Connection points of the start/end fittings. Start by picking already-placed fittings
• Obstacle Avoidance: Automatic obstacle avoidance. Combine with manual tweaks for complex layouts
• 3D Orthogonal: Only orthogonal routes allowed. Easier on-site installation

Field Tips

• Always terminate a pipe with a fitting that has a defined Connection Point. Populate will fail if the end is open
• For welded piping, match the Style's "Engagement" (insertion depth) to measured values
• Isometric Drawing: Generate piping drawings as IDW Base Views, then use Auto-dimension Pipe Run to add dimensions

8. Cable & Harness

A module dedicated to wire routing and harness design. Inventor Professional only.

Components

• Harness Assembly: Harness-specific sub-assembly (.iam)
• Connector: Connector part. Pin definitions must be authored
• Pin: Contact points inside the connector. Authored via Work Points
• Wire / Cable: Individual wires, or bundles of wires
• Segment: The spatial path the harness follows
• Splice: Junction or branch point

Workflow

1. Authoring: Define Pin Work Points and Connector Properties in the connector IPT
2. Place Connectors: Place them in the Harness Assembly
3. Create Segments: Define paths with 3D Sketches
4. Add Wires/Cables: Pin-to-Pin wiring
5. Route Wires: Auto-route along the Segments
6. Report: Export the Wire List to CSV/XML

RefDes (Reference Designator)

Every Connector instance must have a RefDes value. It's the key used when importing a Wire List. When placing the same connector multiple times, assign a unique RefDes to each instance (J1, J2, …).

Field Tips

• Bundle Diameter: The actual diameter of a bundle of wires. Set it on Segment Properties so interference and bend radius calculations are accurate
• Minimum Bend Radius: Defined per wire. Automatically checked during routing
• No general commands inside a Harness: Applying a generic Extrude/Sweep to a Harness object corrupts the data
• Wire List Import: Prepare the wire list in Excel/CSV in advance and import it to generate wires in bulk

→ See also: /cad-tips/inventor/sheetmetal-frame (designing frame bases with Frame Generator)

9. Assembly Design Strategies

• Top-Down: Layout Sketch → Skeleton → individual parts. Suits large mechanisms and custom equipment
• Bottom-Up: Parts first → assemble. Suits designs built around standard components
• Hybrid: Most real-world workflows mix both
• Grounded First Part: Ground the first part at the Origin. A reference point is mandatory

Field Checklist

• Joints are used over Constraints whenever possible
• Every Sub-Assembly contains at least one Grounded Part
• Flexible Sub is enabled only where motion is actually required
• Relationships replaceable by Parameter Link / iLogic are not built with Adaptive
• Contact Solver is scoped with a Contact Set
• Large assemblies are opened via Express Mode or LOD to save memory
• Only used Content Center libraries are checked, and standard libraries are Read-Only
• Tube & Pipe pipe ends are terminated with fittings that have defined Connection Points
• All Harness Connectors have RefDes assigned so the Wire List generates correctly