Design Overview

The RoboFlock rover is a four-wheel, skid-steered outdoor robot built around a 3D-printed structural frame and a pair of 4080 aluminum extrusion rails. The mechanical design optimizes for outdoor durability, modular iteration during prototyping, and a low center of gravity for stability on uneven terrain such as the Black Rock playa.

This page is a high-level walkthrough.

Detailed geometry, fasteners, and CAD files for every part live in the Parts Catalog and the per-subsystem pages linked below.

Design Goals

Stable Sensor Integration — provide a clear 360° view for the LiDAR and a fixed forward placement for the ultrasonic sensors and GPS antenna.
Electronics Accommodation — segregate the battery (low, in a separate compartment) from compute and motor drivers (in the upper hull), with organized cable routing between the two.
Outdoor Operation — maintain a rigid structure, good impact resistance, and a low center of gravity for rough terrain.
Modular Suspension — a rocker-differential linkage that keeps all four wheels in ground contact across uneven terrain without active components.
Iterability — a fully parametric Fusion 360 design so dimensions, mounts, and structural features can be updated without re-engineering the system.

Architecture at a Glance

From the ground up:

Drive corners (×4) — each wheel is driven by a BLDC motor. The motor bolts to a 3D-printed bracket containing a press-fit radial bearing that supports the motor shaft. The keyed shaft drives a clamping coupling, which bolts to a 3D-printed adapter, which carries an 18″ airless wheel.
Side rails (×2) — one 4080 T-slot extrusion runs front-to-back on each side (mounted with the 40 mm face down, 80 mm tall). Both motor brackets on that side bolt to the inner rail of the extrusion; the suspension bracket clamps to the outer rail.
Side suspension pivots (×2) — a printed bracket clamps onto each extrusion (4 bolts: 2 top rail, 2 bottom rail) and carries a 12 mm bore pivot hub. From each hub a hollow rod stub extends inboard. The two stubs meet near the centerline, where a solid linear rod slides inside both halves and acts as the through-shaft bearing surface — letting each side pivot independently.
Main chassis frame — a 3D-printed structure with two L-shaped “ears” that drop down from above the extrusions. Each ear has a press-fit ball bearing whose inner race rides on the OD of the inboard hollow rod. This is the per-side pivot the rest of the body hangs from.
Differential coupling — a 3D-printed rocker-differential arm sits on a vertical shoulder bolt at the front of the main frame. Two pushrod assemblies (threaded rod with a ball-joint rod end at each tip) link this arm to the side suspension brackets — the side-facing rod end couples to the bracket, the upward-facing rod end couples to the arm. This forces anti-symmetric travel: when one side rises, the other is driven down.
Battery compartment — bolted to the underside of the main frame, housing the 3S LiPo and bus-bar wiring.
Hull and top cover — the main hull bolts to the top of the main frame and houses the Jetson Orin Nano and motor drivers. Motor leads route up from the battery compartment into the hull. The hull top latches down, carries the LiDAR (in a twist-lock slot) and the GPS ground plane.

This mechanical architecture is independent (per-side vertical pivot) plus dependent (rocker-differential): each side can articulate over an obstacle, but the front cross-link constrains both sides to share roll axis travel. With no steering linkage, heading is controlled purely by differential torque across the four BLDCs (skid-steer).