PLA

PLA and ABS are the two most common 3D printing materials. Main differences: ① Print difficulty: PLA is easier, no heated bed required (50-60°C improves adhesion), nozzle 190-220°C; ABS needs heated bed (80-110°C) and enclosed chamber. ② Mechanical properties: ABS has better toughness and impact resistance; PLA has higher surface hardness but is more brittle. ③ Heat resistance: ABS HDT ~78°C, PLA only 64.3°C. ④ Eco-friendliness: PLA is made from plant starch, biodegradable, odorless; ABS is petroleum-based with slight odor. For beginners, PLA is highly recommended - high success rate, easy to use.

PLA doesn't strictly require a heated bed, but 50-60°C is recommended for better results. ① Small models (<5cm) or models with large bottom area can print on glue stick/masking tape without heating. ② Large models benefit from 50-60°C bed to reduce warping. ③ Too high bed temperature (>65°C) causes soft Elephant Foot effect. PLA recommended: nozzle 220°C, bed 65°C.

PLA has limited heat resistance, HDT only 64.3°C (1.80MPa), Tg about 62.8°C. ① Indoor use (<40°C) is completely fine. ② Summer car interiors can reach 60-80°C, PLA may soften and deform. For higher heat resistance, choose PLA+ (HDT up to 100°C), ABS, or PETG. Annealing PLA prints (70-80°C for 30-60 min, slow cool) can increase HDT to 80-100°C.

Clogs and breaks are common issues. ① Clog causes: temperature too low (<190°C), moistured filament carbonization, debris in nozzle. Fix: Heat to 230°C and use cleaning needle, or cold pull (heat to 220°C, cool to 90°C, pull out quickly). ② Break causes: tangled spool, extruded gear slipping, uneven diameter. Fix: check spool, clean gear, check filament. ③ Prevention: sealed storage, desiccant, low humidity.

Surface quality improvements: ① Layer lines: reduce layer height to 0.1-0.15mm, calibrate Z-axis, check belt tension. ② Scratches: check nozzle for residue, reduce retraction speed, adjust print speed. ③ Gloss: PLA has natural gloss; use PLA Silk for higher shine. ④ Polishing: 400→800→1500→2000 grit sandpaper for mirror finish. PLA surface has excellent adhesion for painting.

PLA prints are excellent for painting. ① Primer: Vallejo/Tamiya primer fills micro layer lines and improves paint adhesion. ② Direct painting: PLA has good adhesion for acrylic primers directly. ③ Recommended paints: Tamiya/Gunze/Star water-based spray paints have excellent adhesion and even color. ④ Water decals: compatible with PLA, use clear coat for protection. ⑤ Custom effects: masking techniques for gradient/camo. Sand lightly with 400 grit before painting for best adhesion.