The first time I walked into the Composites Additive Manufacturing Lab, I was immediately struck by the CF3D® printer sitting in the center of the room. This wasn't like any 3D printer I'd seen before — it was depositing continuous carbon fiber at temperatures over 400°C, creating parts that could rival traditional aerospace-grade composites. Professor Baur explained that while the technology was groundbreaking, nobody had systematically characterized the mechanical properties of these printed materials. That became my mission.

The CF3D® process is beautiful to watch but incredibly demanding to master. Unlike traditional FDM printing, you can't just stop and start — the carbon fiber tow needs to maintain a minimum length of 25mm or it won't bond properly. This constraint meant I had to completely rethink how test specimens are designed. I spent weeks in SolidWorks developing custom coupon geometries that would give us valid ASTM data while respecting the printer's limitations. Every failed print taught me something new about the material's behavior.

Research isn't glamorous. I spent countless hours in the machine shop with my research partner, carefully cutting and preparing specimens for testing. Each sample had to be precisely dimensioned — any variation would compromise our results. We developed a workflow that minimized waste while ensuring each specimen met ASTM specifications. The smell of carbon fiber dust became oddly comforting, a sign that we were making progress.

The Instron machine became my second home. I ran dozens of tensile tests following ASTM D3039, carefully mounting each specimen and watching the stress-strain curves develop in real-time. There's something almost violent about watching a carbon fiber sample fail — one moment it's holding over 1300 MPa of stress, the next it explodes into a shower of fractured fibers. We established an ultimate tensile strength of 1395 MPa, which was actually higher than I expected for an additively manufactured material.

The short beam shear tests were equally revealing. Following ASTM D2344, I subjected samples to three-point bending until interlaminar shear failure occurred. The shear strength came out to 66.59 MPa — respectable, but the failure modes were fascinating. Each fractured sample told a story about how the layers bonded during printing. I spent hours under the microscope analyzing failure surfaces, trying to understand what made some samples stronger than others.

By the end of my time in the lab, I had generated the first comprehensive mechanical property dataset for CF3D® composites at our university. These numbers matter — they give engineers the confidence to actually design with these materials. My technical paper summarized everything I learned, and presenting to that panel of professors was genuinely nerve-wracking. But seeing my data cited in their subsequent work? That made every late night in the lab worth it.