Part Cooling

Theory

Part cooling fans blow air onto the printed layer immediately after extrusion. Rapid cooling is essential for overhangs, bridges, and fine detail, as it solidifies plastic before gravity causes sagging. However, excessive cooling harms interlayer adhesion in crystalline and high-temperature polymers. PLA benefits from high cooling (80-100%); ABS and polycarbonate require minimal or no cooling (0-20%) to prevent warping and delamination; PETG sits in the middle (30-50%).

Application

Set cooling to 100% for PLA after the first 2-3 layers. For ABS, disable part cooling or use 10-20% max. For PETG, use 30-50% to balance adhesion and overhang quality. Increase cooling speed for bridging and overhang sections using per-feature settings. Ensure the cooling duct covers both sides of the nozzle evenly for uniform cooling.

Common mistakes

Cooling the first layers too aggressively detaches them from the heated bed. Asymmetric cooling duct causes one-sided warping and differential shrinkage. Mini fans with poor static pressure cool poorly at high speed: replace with radial blowers. Cooling hot-end motor (stepper) or heater block with part cooling air causes temperature fluctuations.

Related terms: Layer Adhesion, Overhang, Warping