Modular Truss Bridge Connector - 3D Printable STEM Project

Credit to the Original Creator

This model is inspired by the classroom project “3D Printing Truss Bridges” created by the user “PolarCloud” and published on the website https://www.instructables.com/3D-Printing-Truss-Bridges.

Bridge Connectors

This 3D-printable truss bridge connector was designed for educational and DIY projects on the platform instructables.com by the user “PolarCloud”. It is ideal for teaching structural engineering, geometric design, and 3D printing. The connector serves as the main joint for assembling a truss bridge and allows for the secure attachment of skewers or similar materials in a triangular pattern. It’s ideal for classroom activities, STEM projects, or for anyone interested in exploring bridge design and 3D modelling.

I have recreated the connectors to fit wooden skewers of 2.9 mm diameter.  I have also made the bottom flat to improve adhesion to the print bed.

Teaching the Project in the Classroom

You can find all the necessary information on how to teach the project on the original website: https://www.instructables.com/3D-Printing-Truss-Bridges

Here is the approach in short:

• Print at least 14 connectors per bridge (better more).
• Follow the pictures on https://www.instructables.com/3D-Printing-Truss-Bridges how to assemble the bridge.
• Per Bridge you need wooden skewers (see my recommendation below) which are cut to the correct length:
  • 19 x 10 cm
  • 10 x 15 cm

Key Features:

• Simple, modular design for easy assembly and customization.
• Compatible with standard skewers (adjustable size for different materials).
• Encourages hands-on learning about load distribution and structural integrity.

Usage

Print multiple connectors to build a sturdy truss bridge. Test your bridge’s strength by gradually adding weights and analyzing its performance. Great for collaborative projects and competitions!

You will need wooden skewers or similar sticks to assemble the bridges. I purchased this product from the German supermarket Edeka. The diameter of these skewers is approximately 2.9 mm..

Print Instructions

Print in the upright position with no supports needed. I used PLA, but I think PETG would work too.

Modifying the Model

You can rescale the connector if you use skewers with a different diameter. Your second option is to modify the OpenSCAD model.