Why 3D Printers Use Two Cooling Fans | Hotend and Part Cooling
An FFF printer heats plastic at the nozzle, yet it also needs cooling nearby. The hotend fan and part-cooling fan serve different places and should not be treated as interchangeable.
Follow the air through the process
Keep the upper hotend cool
The hotend fan drives air between the heatsink fins. This removes heat from the upper assembly so unwanted heat does not spread too far along the filament path.
The heat break separates warm and cool regions
Below the heatsink, the narrow heat break limits heat conduction from the heater block. The nozzle stays hot enough for extrusion while the upper feed region remains cooler.
Part cooling acts after extrusion
A separate duct aims air at the newly deposited material below the nozzle. This helps the printed shape cool and set; it is not the same air path as cooling the heatsink.
Cooling demand changes with the material
Part-cooling demand varies with material, layer and geometry. A bridge may need a different setting from a first layer. Use the validated print profile instead of assuming full speed is always best.
Airflow function
- Drive air through the heatsink channels to limit heat travelling up the filament path.
- Use the separate part-cooling circuit to cool freshly deposited material when the print profile calls for it.
- Maintain the distinct pressure, wiring and control requirements of the two fan circuits.
What can change the result
- Insufficient heatsink airflow can allow filament to soften too high in the hotend.
- A blocked or misdirected part-cooling duct misses the newly deposited material.
- A part-fan setting unsuitable for the material or print stage can harm the intended print result.
Start with the complete air path
Share your layout and the information you already have. Unknown values can be identified before a configuration is selected.
Match the fan to this air path
LONGWELL supplies compact DC axial and blower families. Share the heatsink or nozzle-duct resistance, voltage, available space and control requirements. Confirm each fan with the assembled print head before choosing a model.
Where it sits
The shown axial family belongs to evaluation of the hotend-heatsink air path. The part-cooling fan has a separate path from its blower outlet through the nozzle duct toward the newly deposited material.
Why consider this configuration
Specify two operating points and two control duties. Heatsink channels need dependable heat removal; the part-cooling duct has its own resistance and material-dependent airflow demand. Mounting, wiring and temperature limits must match each circuit.
Check the result in your equipment
Discuss your 3D printer hotend and part cooling requirements
Send the heatsink and part-nozzle layouts separately. Include mounting dimensions, loaded flow and pressure loss, voltage, connector pinout, control and feedback signals, operating temperature and material profiles.
A layout, installation photos or your existing model is enough to start the discussion.