3D Printer Cooling Fan — 24 V Hotend, Part Cooling & Enclosure
An FDM printer uses three fans for three different jobs: a heatsink fan that must never stop, a part-cooling fan that has to push air through a printed duct, and an enclosure or electronics fan that keeps the mainboard and PSU alive. Each has its own failure mode. We build the sizes printer manufacturers actually specify — 3010, 4010, 4015, 5015 and 6015 — in 12 V and 24 V DC, as axial fans and as blowers.
Part of: cooling fan applications · also relevant to LED lighting.
The three fan jobs on a printer
- Hotend heatsink fan. Runs continuously during a print. If it stops, the filament softens above the melt zone and the hotend clogs — which is why this is the one position where a 24 V fan on a 24 V rail, with a tachometer output, is worth the extra cost.
- Part-cooling fan. Works against the pressure drop of a printed duct, often a long, narrow channel. A blower develops far more pressure in the same footprint, which is why 5015 blowers are standard on most cartesian printers.
- Electronics and enclosure fan. Keeps the mainboard drivers and the PSU cool. This is where a 60 or 80 mm axial fan at low speed does the job quietly.
Fan sizes and voltages for 3D printers
| Frame | Typical position | Voltage | Models |
|---|---|---|---|
| 30 mm | compact hotend, small driver board | 12 / 24 V DC | DC 3010 |
| 40 mm | hotend heatsink, extruder motor | 12 / 24 V DC | DC 4010, DC 4015 |
| 50 mm blower | part-cooling duct | 12 / 24 V DC | Blower 5015, Blower 5020 |
| 60–80 mm | mainboard, PSU, enclosure exhaust | 12 / 24 V DC | DC 6015, DC 8025 |
Why printer fans fail early
- 24 V fan on a 12 V rail. It turns, but at half speed and with almost no pressure margin, so the hotend heat-creeps on long prints. Match the winding to the rail, and check the rail under load.
- PWM frequency mismatch. Controllers switch part-cooling fans at low frequency for compatibility with cheap fans; a fan designed for 25 kHz PWM will buzz or refuse to start. Tell us the drive method.
- Sleeve bearing in a heated enclosure. An enclosed printer runs at 50–60 °C for hours. A sleeve bearing loses its lubricant film and starts to squeal well before its rated hours.
How to specify a printer fan
- Rail voltage measured under load, not the nameplate figure.
- Drive method: constant DC, low-frequency PWM, or 4-wire 25 kHz PWM.
- Duct pressure drop for part cooling, which usually decides axial versus blower.
- Acoustic target — a printer in a bedroom is a different product from one in a workshop.
- Connector type (JST-XH, Molex, bare leads) and lead length to reach the board.
Questions from printer makers
Do you supply 24 V 4010 and 5015 fans with JST connectors?
Yes. Connector type and lead length are configurable on the same frame, so a 4010 or 5015 can ship with the JST-XH plug and the lead length your harness needs instead of bare wires.
Axial fan or blower for part cooling?
A blower, in almost every case. The printed duct is a high-resistance path and an axial fan loses most of its flow against that restriction. A 5015 blower in the same footprint will deliver noticeably more air at the nozzle.
Can I get a fan that reports its speed?
FG tachometer output and RD locked-rotor alarm are available on our DC fans. On a hotend heatsink fan that is the difference between a firmware warning and a ruined print.
Related: Medical & lab devices · LED stage lighting · All DC blowers
Send the position, the rail and the duct you are working with, and we will propose a fan and a speed version to test. Request samples.