Suspension System

Description:

The suspension system includes an independent passive system for each individual wheel. It was designed around a holder that would support the suspension of two wheels. This holder includes an upper arm and a lower arm, which connect to a support structure (upper and lower) for the motor.

There were several iterations of this system. Initially, the goal was to create an active suspension system with a seesaw motion. However, this idea was discarded due to the potential difficulties and how time-consuming the construction and testing processes could be. The design was then switched to a passive suspension system using springs (although options using elastic bands or other tension-based methods were also explored) as these offered greater flexibility and allowed each wheel to be customized independently, creating a balanced chassis that could be modified considering the weight that was put in it.

Between the regional and national competition, a lot of changes were made. The most relevant one included the placement of the springs. They were placed between the chassis and the upper arm of the suspension. However, before the regional competition, these were suspended very little, allowing for not much maneuver of movement when facing an obstacle. For the national competition, lock nuts were used, which allowed for the springs to be suspended much more, since the screws were locked in place, which made the range of motion of the suspension more useful when facing high obstacles.

Challenges

The main challenges were related to the strength and durability of the different parts, which were affected by both the design and the position in which they were printed.

In terms of design, the thickness of the components changed throughout the iterations. For example, the lower suspension arm initially consisted of two thin, separate parts. To improve the design, these were combined into a single, thicker piece. This not only improved structural strength but also simplified the assembly process.

Additionally, print orientation played a significant role in the strength of the components. Properly and strategically orienting the parts during 3D printing proved essential to achieving the required performance without breaking.

One of the most common issues was the constant breaking of the motor supports, both upper and lower. Small or easy changes like the printing orientation and improving thickness helped solve this issue for the national competition.