This is the heatsink fan rather than the part cooling fan: it blows across the cold side of the hotend on the CR-10 Smart Pro and the Ender-3 S1, S1 Pro and S1 Plus. When it slows or stops, filament softens too far up the throat and the machine starts jamming a few hundred layers into a print, which is a frustrating fault to chase. Replacing it is a wiring job rather than a strip-down: the motherboard and harness stay where they are, and the supplied connectors join onto the existing leads. Brushless, quiet in use, and supplied with a manual.
Good for
- Curing repeated mid-print jams
- Keeping a hotend heatsink cool
- Ender-3 S1 series maintenance
- Quieter running on an older toolhead
