Hobby FDM can print wearable cosplay armor. Most failed plates are settings, not the model.

1. Stand plates on the long edge. Flat on the bed warps. Upright, layer lines follow the curve and sand faster.

2. Stop printing armor at 0.12 mm. You will sand it. 0.28–0.32 mm, 0.4 mm nozzle. Faster, stronger walls.

3. Walls beat infill. 4–5 walls, 15–20% gyroid. Vase-mode chests dent when someone hugs you in the photo line.

4. PETG for flex, PLA for helmets. Thighs, abs, anything that bends when you sit: PETG. Helmets and hard pauldrons: dry PLA is fine.

5. Split on real armor seams. Cut at belts, rivet lines, and plate overlaps. Never through the middle of a smooth curve.

6. Dry the filament. If the first 20 mm sounds like Rice Krispies, the file is not the problem. 4 hours at 45 °C for PLA, 65 °C for PETG.

Glue: CA + baking soda for PLA joints. Two-part epoxy for PETG. Superglue alone on PETG lets go mid-con.

If a piece still splits, post the layer height, material, and a photo of the break. Orientation is usually the fix.