Frame and Extrusion

The structural backbone of the RoboFlock is split between two parts that work together: a pair of 4080 aluminum extrusions running along the sides of the robot, and a 3D-printed main chassis frame that hangs above and between them.

This split keeps the high-load mounting interfaces (motor brackets, suspension brackets) on rigid metal extrusion, while the printed frame carries the lower loads associated with the body, battery compartment, and hull.

Side Rails - 4080 Extrusion

Each side of the robot has a single length of 4080 T-slot aluminum extrusion running front-to-back. The profile is mounted with the 40 mm face down, so the rail stands 80 mm tall.

Each rail provides two structural functions:

Inner rail (the face pointing toward the centerline of the robot) - the rocker beam bracket for that side clamps around this rail, anchored with 4 bolts (2 into the top T-slot, 2 into the bottom). This provides the mounting interface for the printed main chassis frame, which sits between both extrusions
Lower rail - (the face pointing downward) - the two motor brackets for that side bolt to this rail, 3 bolts each, into the T-slot.

See RV1-CHS-FRM-001 in the Parts Catalog for sourcing and exact length.

Note

Length, fastener size, and T-nut style are still TBD in the catalog - confirm with assembly hardware once the first set is sourced.

Main Chassis Frame

The main chassis frame (RV1-CHS-001) is the largest single 3D-printed part on the robot. It serves three roles:

Mounts the body, battery compartment, and hull (top + bottom screw interfaces).
Provides the suspension pivot ears - two L-shaped projections that drop down. Each ear contains a press-fit bearing whose inner race rides on the outer diameter of the suspension’s inboard hollow rod stub. This pair of bearings defines the per-side suspension pivot axis.
Anchors the rocker differential arm - at the front of the frame, a shoulder bolt threads upward into the frame, providing a vertical pivot for RV1-SUS-001.

Note

The “ears” carry the entire suspended weight of the robot through their pressed bearings. Inspect for layer delamination or insert pull-out before each test session and re-print if any cracking is visible around the bearing seats.

Load Path Summary

Vertical load travels:

Hull, electronics, battery
          │
          ▼
    Main chassis frame
          │
          ▼
Bearings in frame ears
          │
          ▼
   Hollow rod stubs
          │
          ▼
    12 mm pivot hubs
          │
          ▼
  Rocker beam brackets
          │
          ▼
     4080 extrusions
          │
          ▼
Motor brackets ───► Motors ───► Wheels ───► Ground

The differential arm and its pushrods do not carry vertical load directly - they constrain anti-symmetric pivot motion between the two sides, and absorb only the differential force needed to enforce that constraint.