Lost while selecting fans

  • So I recently ordered my duet wifi and now I´m planning to exchange a few parts on my printer while I upgrade my board to the duet as well. Especially my hotend mount and part cooling fan were bothering me quite a lot. I´m planning to use either 3 40 mm fans (two for parts and one for hotend) or one 30 mm and 2 40 mm ones.
    The problem now is, that I got pretty lost searching for the correct fans. As far as I´ve seen the board only has two connectors for the fan but unfortunately most 40 mm fans have 3 wires. How would I connect these to the board nd would I still be able to adjuste the fan speed?

    Furthermore, do you have any rcommendations on 30 and 40 mm fans?


  • administrators

    2-wire 40mm fans are readily available on eBay and elsewhere. However, you can use 3-wire fans. The 3rd wire is normally coloured yellow and is the tacho output. You can leave it unconnected.

    Most brushless fans work with PWM, but a few types don't.

    I got fed up of fans becoming noisy after a while, so last time they needed replacing I ordered 2 fans with ball bearings instead of sleeve bearings, from a Chinese seller on eBay. They have been good so far. I'd post a link, but that listing is no longer available.

  • To add to what David has said, this is a good resource, even if you don't buy from them. https://www.mouser.co.uk/Thermal-Management/Fans-Blowers/_/N-axg88/. Change the location if you are not based in the UK. Use the filters to "drill down" to DC fans, then the frame dimensions, then the voltage. You can further filter by bearing type etc etc.

    The reason I find it useful is that it gives you noise level and airflow (there is usually a trade off) as well as lots of other info.

    BTW. You'll find that with the Duet board, the stepper motors may be a lot quieter than you are used to so fan noise starts to become intrusive. My advice would be to pick the quietest fans that will do the job.


  • Thanks you David and deckingman for the quick reply! 🙂

    @deckingman special thanks to you, the site provided is great for comparing different brands

  • Quick follow-up question. 😉

    I stumbled upon some quite neat fans from sunon with "Vapo" (magnetic) bearings. They are advertised as being quieter than the human hearing capacity and more durable than ball bearings. Since they are about 8 bucks each I´m a bit hesitant to buy them straight away. Does anybody have experience with these fans? https://www.conrad.at/de/axialluefter-12-vdc-9-mh-l-x-b-x-h-40-x-40-x-10-mm-sunon-ha40101v4-0000-999-184264.html (sorry, it´s in german)

Log in to reply