Week 5: Trailing Arm

With the Double Wishbone assembly progressing well, I’ve shifted my attention to designing the second suspension configuration, the Trailing Arm system. This phase has involved a lot of careful thought about how the geometry of a trailing arm differs fundamentally from the wishbone setup, and how to translate those differences accurately into a printable CAD model. Where the Double Wishbone relies on two lateral control arms to manage wheel motion, the Trailing Arm mounts behind the wheel hub and controls movement longitudinally, which changes how forces are distributed through the chassis during impacts and cornering. Getting those relationships right in the model is critical if the final comparison between the two systems is going to mean anything scientifically.

One of the more significant design decisions made this week was the choice to split the base plate into two halves since the Double Wishbone is mounted to a compact bulkhead while the Trailing Arm hinges way further from the wheels. This is a meaningful step forward for the integrity of the experiment, as a successful modular chassis isolates suspension geometry as the sole variable and reduces the chance that structural differences between two separate builds could influence the results. An All Wheel Drive drivetrain seems plausible as of now, but if I can’t find driveshafts that are interchangeable for the two systems, I will have to resort to Front Wheel Drive. There is still refinement to be done before this assembly is ready for the printer, but the foundation is in place.

Next week, I am planning a visit to my mechanic shop to get some real-world perspective on how these systems are designed, built, and serviced at full scale, which should inform some of the finer design details still to be worked out.