How to generate cable tray elbows using BIM

Cable tray elbows in BIM can be generated in Revit either by using preloaded fitting families, creating custom elbow families, or automating placement with Dynamo scripts.

Manual Creation Using Revit Fittings

1. Load the Correct Families: Ensure that your project uses the MEP template and that cable tray fitting families (45° and 90° elbows) are loaded into the project .
2. Place Straight Trays: Draw straight cable tray runs in your floor plan view, setting the tray size, system type, and elevation in the properties palette .
3. Add Elbows: When a tray changes direction, Revit can automatically generate elbows if the correct fitting families are loaded. For a 45° elbow, two segments are typically used, and for a 90° elbow, three segments are required .
4. Adjust Parameters: Modify the elbow properties such as radius, angle, and elevation to match design requirements. Proper parameter setup ensures accurate connectivity and routing behavior .

Creating Custom Elbow Families

• Use the Family Editor in Revit to create custom elbow geometries if standard fittings do not meet project specifications.
• Define reference planes and parameters for angles, radius, and width to allow flexibility in placement.
• Save the family and load it into your project for use in cable tray routing .

Automating Elbow Generation with Dynamo

1. Dynamo Script Setup: Dynamo can read CAD lines or Revit elements to automatically generate cable trays, including elbows, tees, and steps .
2. Define Tray Properties: Set tray width, type, elevation, and direction changes within the script.
3. Automatic Placement: The script can place elbows at intersections or directional changes without manual intervention, saving time on large projects .
4. Integration: Dynamo scripts can be integrated with Revit to handle complex layouts, ensuring consistent and accurate elbow placement across the model .

Best Practices

• Always start with the correct MEP template to ensure all necessary families and settings are available .
• Load all required fitting families before beginning routing to avoid missing connections.
• Use Dynamo for repetitive or large-scale projects to improve efficiency and reduce manual errors.
• Verify elbow placement and connectivity in 3D views to ensure proper routing and clearance. By combining Revit's built-in fittings, custom family creation, and Dynamo automation, you can efficiently generate cable tray elbows in BIM, ensuring accurate, professional, and scalable electrical designs.