Before diving into the specifics of Resin Prints, it’s crucial to establish a baseline for comparison. We previously conducted tests using PLA (Polylactic Acid) prints, evaluating the strength of heat-set inserts and tapped threads. These PLA results serve as an excellent reference point to understand the performance characteristics of resin prints in similar applications.
In our PLA testing, heat-set inserts demonstrated remarkable strength. Mounted in a custom jig on our DIY Universal Test machine, PLA samples with heat-set inserts withstood an average load of 205 kg before failing. The failure mode was quite dramatic, with the inserts violently ripping out of the PLA, yet surprisingly, the surrounding part remained largely intact. The consistency of these results, indicated by the low data scatter, underscores the reliability of heat-set inserts for applications demanding consistent performance in PLA.
Conversely, tapped M3 threads directly into PLA exhibited lower strength. These tapped PLA threads failed at an average load of 163 kg. The failure mechanism observed was thread shear, where the plastic threads stripped and detached, often remaining adhered to the bolt. This type of failure is typical when a weaker material, like PLA in this case, forms the female thread.
Understanding thread failure modes is essential when working with 3D printed parts, including resin prints. Beyond thread shear, another common failure is thread jumping. This occurs due to the angled nature of threads, generating radial forces that can stretch the surrounding material. If the material around the female thread is soft or thin-walled, the threads can “jump” over each other with minimal damage. A third, more catastrophic failure mode is total destruction, where combined radial, axial, and hoop stresses completely obliterate the part. This comprehensive destruction is something we anticipated observing more frequently with resin prints due to their inherent material properties.
Having established these PLA benchmarks, we can now turn our attention to how resin prints perform under similar stress conditions. Resin 3D printing offers different material properties compared to PLA, often resulting in parts with higher detail and potentially different mechanical behaviors. Understanding how heat-set inserts and tapped threads behave in resin prints is vital for engineers and hobbyists alike who utilize resin 3D printing for functional parts. Further investigation into resin prints will reveal whether they exhibit similar strength characteristics to PLA, or if their unique properties lead to different performance outcomes when employing these fastening methods.
