Strange failure rate of fans



  • Hi, I appear to be getting through fans, both hotend and part on a regular basis. They seem to present the same fault, at first they run absolutely fine, but after a few months then they don't start up on their own, but if you manual flick the blades then they start spinning properly. after a while though they just wig out completely.

    Now I may just be buying bad fans, but I have experienced this phenomena 4 times in four months with both axial and radial fans. Everything runs at 24V. Do I have the correct settings?

    ; Fans
    M106 P0 S1 I0 F500 H1 T45 ; Set fan 0 value, Extruder 1 Fan. PWM signal inversion and frequency. Thermostatic control is turned on
    M106 P1 S0 I0 F500 H-1 ; Set fan 1 value, Extruder 1 Part Fan. PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P3 S1 I0 F500 H2 T45 ; Set fan 1 value, Extruder 2 Fan. PWM signal inversion and frequency. Thermostatic control is turned on
    M106 P7 S0 I0 F500 H-1 ; Set fan 2 value, Extruder 2 Part Fan.PWM signal inversion and frequency. Thermostatic control is turned off


  • administrators

    Those fan settings look OK to me. 500Hz may be too fast a PWM frequency for some fans, but it should not affect the fully-on behaviour.

    I suspect the problem is caused by the type of fan you are using. When I converted my delta to 24V a few years ago, I used three 40mm 24V fans sourced from a UK supplier. After a few weeks of use they became noisy. So I replaced them with ball bearing fans (the originals had sleeve bearings) bought from a Chinese supplier vie eBay. They are still running well today.



  • Do you have the specs of the fans? Do they come with a MTBF rating? Personally, I'm a bit of a fan nut. I can't stand loud fans and I can't abide by fans that might just up and die on me, so I always buy quality fans from reliable places. Cheapo fans will die, and if they are of the same make and model, they will likely all fall to the same fate.

    I have switched entirely to Sunon or Noctua fans. Accept no substitute. I've never had one of these brands fail on me.



  • cheap fans, like almost everything else, are cheap for a reason...



  • I did once cave and buy a 3 pack of blower fans from amazon for 5$ free shipping. The first fan I hooked up had a loud pop sound and an awful awful smell. It released the blue smoke. I took it off and peeled back the sticker. And underneath I saw that the black wire was connected to the terminal screen printed with a plus sign and the red wire was connected to the terminal screen printed with the minus sign. I figured out why they were so cheap. I checked the other fans, same thing. I wired another one up again, this time with wires reversed, and it worked. It was loud, but it worked. I immediately went to digi-key and ordered a sunon blower. Luckily it didn't kill the board.



  • I suggest buying some Sunon fans, they even have some 5015 blower fan like MF50151VX-A99, they are not the quiets but super powerful. If it it is too loud you can easily run it at lower PWM and they still will coll even PLA fine.



  • Thanks to everyone for their comments, so, and let me take a moment to reflect here, but yes, you are all accusing me of being a cheapskate 🙂

    I can't use Noctua as they don't do 24V 40mm axial or 40mm
    blower and Sunon don't do any small blowers.

    Any other suggestions?

    Here's the one I have at the moment
    0_1558076099453_fan.jpg

    dc42: you say 500Hz may be a bit fast. what would be the standard setting?

    Thanks


  • administrators

    @pcsentinel said in Strange failure rate of fans:

    dc42: you say 500Hz may be a bit fast. what would be the standard setting?

    The blower fans I have tried don't like PWM at all. They sort of work at very low PWM frequencies e.g. 10Hz.



  • @pcsentinel said in Strange failure rate of fans:

    Thanks to everyone for their comments, so, and let me take a moment to reflect here, but yes, you are all accusing me of being a cheapskate 🙂

    I can't use Noctua as they don't do 24V 40mm axial or 40mm
    blower and Sunon don't do any small blowers.

    Any other suggestions?

    Here's the one I have at the moment
    0_1558076099453_fan.jpg

    dc42: you say 500Hz may be a bit fast. what would be the standard setting?

    Thanks

    Just search the web for "24V radial"!

    I remember from my buildup that these companys could have radial-blowers with 24Vdc, but some of them a little bigger then 40mm, maybe 50 or so (you could put a 24vdc-12vdc dcdc-converter to use 12Vdc fans also?):

    • sunon
    • ebmpapst
    • minebea
    • sepa
    • wallair
    • panasonic
      ... search the web for "ONE-OF-THE-ABOVE-LISTED-VENDOR fan alternative"

    Most big electronic-stuff-vendors have really nice websites nowadays where you can just navigate to your product-category, then input your constrains, and it throws back what is left, companies like:

    • distrelec
    • conrad
    • rs-components
    • digikey
    • mouser
    • farnell
    • Newark
    • element14
      ... search the web for "ONE-OF-THE-ABOVE-LISTED-VENDOR alternative"

    The web might throw up a hundred more companies/vendors! Good luck! Of course you can always with a little risk "gamble"-buy on alibaba, ebay, etc. Most of the stuff just runs fine...

    Also you can always make a small circuit where you address the problems with some components to cancel it out, that written here, I am not good at it 🙂

    EDIT: Sorry for the long post. And yes, I am also using cheap components, they might not come with a 100%-part check, but are budget-friendly 🙂



  • @pcsentinel said in Strange failure rate of fans:

    I can't use Noctua as they don't do 24V 40mm axial or 40mm
    blower and Sunon don't do any small blowers.

    Just get a step down converter and connect it + output to the middle pin of V_FAN select jumper.
    This is really the best solutions since they are much more 12V fans then 24V.



  • I really like Delta BFB series. If you can use 12V motors it's a really solid option and pretty quiet at a given flow rating. They have a lot of options to choose from, sometimes as many as five flow rate (RPM) choices for a given package size.



  • @pcsentinel

    EDITEDIT-idea: Maybe increase the 100% startup-time to 5seconds or so to blow out any dust?

    Maybe dust and or heat (too close to the extruder?) kill your fans?

    I consider myself as lucky, that I could print parts at the local university out of high-temperature-PolyCarbonat on an Ultimaker-3 with which I printed "frames/hinges" with which I could "decouple" the fans thermically from the metal-hotends and other stuff to decrease the risk of a shorted life of those fans because of thermal stress. Having a strong 100% blow when "firing up" the duet2 helps keep the dust out.


 

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