These fans are killing me slowly



  • Alright guys, tell me why my part cooling fans don't work anymore as of this morning after a few weeks of perfect performance. My always on fan is spinning as it should, but I cannot get my part fan to turn on. I think the part fan might be shot but even if I connect a known-working fan to the part cooling fan output, it still doesn't turn on.

    The fuse looks fine, and the jumper is on 12v. I have no idea what to make of my fan configuration in my config.g but here it is anyways.

    ; Fans
    M106 P0 S0.3 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P1 S1 I0 F500 H1:2 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
    M106 P2 S1 I0 F500 H1:2 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

    I had 2 part cooling fans when I first built this printer but I have since removed the second one and am only using 1.

    I cannot get the part fan to turn on with any g-code or slider on the controller.

    Any ideas?

    Thanks

    PS unrelated, but what is the I command for in the M106 line? and the F? and I understand that H is for thermostatic control but why is it H1:2? I can't find that information on the duet wiki. I have DC fans for everything, is there a way to disable PWM and just send it a DC signal to turn on?



  • your unrelated:

    according to: https://duet3d.dozuki.com/Wiki/Gcode#Section_M106_Fan_On

    the H1:2 sets thermostatic control for that fan, for heater 1 and 2

    so, fan 2 (p2) S1 (100%) l0 (can go to zero speed) F500 (pwm frequency 500) H1:2 controled by heaters 1 and 2 t45 (when either heater over 45)



  • M106 P0 S0 I0 F500 H-1

    try this, this is what my part fan looks like.



  • I omitted all of my fan codes in the config file and added your line, and it didn't change anything. I cannot turn on my part cooling fans with g-code or the slider. The always on fan still works fine.



  • @mklein23 The only difference between @tenjin's line and yours is that he uses S0 and you use S0.3 which means that he turns his fans off by default when first booting up the Duet whereas you set yours to come on at 30%.

    If the fan always used to work but now you can't turn it on by gcode or the slider, and you haven't altered anything in your configuration, then it has to be the fan or wiring or perhaps a blown Mosfet on the board. What happens if you swap the hot end fan for the part cooling fan. i.e. plug the hot end fan into the part cooling fan connector on the board and vice versa. If the fault moves with the fan, then it's the fan. If the fault stays with the connector, then it's the board.



  • @deckingman said in These fans are killing me slowly:

    perhaps a blown Mosfet on the board

    How do I know which mosfet? can I order a new one and replace it myself?



  • @mklein23 said in These fans are killing me slowly:

    @deckingman said in These fans are killing me slowly:

    perhaps a blown Mosfet on the board

    How do I know which mosfet? can I order a new one and replace it myself?

    Let's not jump to any conclusions yet. Swap the fans first.



  • @deckingman said in These fans are killing me slowly:

    If the fault stays with the connector, then it's the board.

    This is the case. I have used one fan that I know works and plugged it into all the connectors. it only turns on when in the 'always on' connectors.



  • @mklein23 It might simply be a fuse. Unfortunately I have a very early board which does not have any fuses but later boards do. So what I don't know is whether the fuse protects all fans, or just the PWM fans.

    If it isn't a fuse, then one last thing to check. Take the fan that you know works, plug it in to Fan0 and send M106 P0 S255. That should turn it on fully. If it doesn't run, then it seems like it's a board failure (but I'm just an end user like you so I could be wrong). If it is a problem with that fan output, then you still have another that you can use instead - Fan2. See here for how to use that output instead of Fan 0. https://duet3d.dozuki.com/Wiki/Connecting_and_configuring_fans



  • I did have the fuse blow, when I first got the board and I wasn't paying attention to how I was connecting everything, so the fuse was the first thing that I checked. I have version 2.0xx of the duet wifi. Since it's just the part cooling fan connector that's not working, I think I might patch the part cooling fan into the always on fan connector for now to stay operational while I wait for a new mosfet.

    Of course I get this failure right after I accept an order for printing...


    Also I had a serious geek out watching your youtube video about the mass-cancellation gantry that you made for your beast of a printer. I have serious machine envoy.


 

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