For RC car enthusiasts and hobbyists, the allure of customization and repair often leads to exploring 3D printing. I’ve personally experimented with 3D printed RC car parts, and while some have proven surprisingly robust, others highlight the technology’s limitations, particularly concerning layer adhesion in FDM printing.
My journey began by printing parts for my CW01 to poor man’s monster beetle conversion. Initially, I opted to print rear trailing arms, mimicking the style of the ORV chassis. Unfortunately, both arms succumbed to breakage in the exact same location, a mirrored failure point that underscored a design weakness or material limitation. To address this, I redesigned the downloaded parts, originally intended for miniguy71’s grasshopper independent rear conversion. My modification involved incorporating M3 bolts running perpendicular to the layers, effectively adding compression and significantly improving durability. Since this reinforcement, these redesigned arms have held up admirably under stress.
However, not all 3D printed parts lend themselves to such straightforward reinforcement. Design constraints or the inherent nature of FDM printing might limit options for strengthening parts in specific orientations. Recognizing this, I’ve also invested in a resin printer and a bottle of tough resin. While I haven’t extensively tested resin-printed parts yet, my understanding is that resin printing offers more uniform strength characteristics, potentially overcoming some of the layer adhesion weaknesses inherent in FDM. Intriguingly, I’ve seen discussions and videos about blending tough and flexible resins to achieve optimal material properties – a balance of flexibility to prevent cracking and high strength for overall resilience.
This leads me to consider a potential workflow: leveraging FDM printing for prototyping and fit-checking due to the cost-effectiveness of filament, and then transitioning to resin printing with tough resins for the final, functional parts where FDM might fall short in terms of strength and durability.
Body posts, specifically, have been a recurring point of failure with FDM and PLA filament. I’ve experienced numerous PLA body posts snapping under stress. However, my recent experimentation with U95 TPU filament has yielded promising results. The layer adhesion with TPU appears exceptionally strong, and the material’s inherent flexibility seems ideally suited for body posts. This combination of strength and flexibility, especially for less tall body posts (and mitigated further by internal shell supports to reduce body shake), suggests TPU as a superior material choice. While TPU can be more challenging to print, in applications where its properties align, like body posts, it appears to offer a significant performance advantage.
