PrintLoop

PrintLoop is an AI assistant for FDM 3D printing, built for the AMD Developer Hackathon: ACT III (Track 1, Intelligent Industry). When a print fails, operators usually guess the cause, tweak slicer settings and retry, wasting filament and machine time. Existing tools detect failures or correct the printer in real time, but none turn a visible defect into a lasting, verified change to the slicer preset. In Mode 2, the operator uploads the printed .3mf project and a few photos of the part. A fine-tuned Gemma 4 E4B names the defects, and Gemma 4 26B judges severity and picks a fix from candidates supplied by a fixed knowledge base, so it cannot invent parameters. If the two models disagree, the operator decides. A validator limits the change (at most two parameters, fixed steps, material limits), the project is re-sliced headlessly with the slicer that created it, and a G-code pre-flight check confirms the change actually shows up before anything is printed. The operator approves, rejects or edits the fix. The loop stops at a good part or after three attempts, and every step is logged. Mode 1 watches the printer camera, raises an alert only when a defect persists across several frames, and proposes a pause that only a person can send. Status: Mode 2 works end to end with a web UI. The right fix was chosen in 7 of 8 test cases with deliberately induced defects, and the fine-tuned detector scores 93.8% on its test split, up from 18.3% before fine-tuning. Built to serve the models with vLLM on ROCm on an AMD MI300X, with llama.cpp as a local fallback. I changed the last sentence to “built to serve” rather than “served on” the MI300X. The repo hasn’t run the models there yet, and the friction log says the droplet couldn’t be created.