Tool Fan not working properly



  • I had my Duet working great for a few weeks before I decided to tear it apart for an Extruder upgrade, and the entire machine has been nothing but trouble since. Currently that comes with problems on the Part Cooling fan.

    While it had been working great before, I am having a lot of problems getting the fan to run properly. Here is the rundown of my problems...

    -Fan was running fine for a while
    -Fan stopped being powered unless at 100% PWM
    -Increasing frequency from 500Hz to 23000Hz worked, fan worked great
    -After a single print, the fan no longer works. Barely spins, stuttering at just about any frequency.
    -After swapping the fan to F1 port on the board, it appears to work great at any frequency

    It seems to me like my F0 port is malfunctioning. Because that's what it defaults to for part cooling in Gcode, that sounds like a problem. Am I doing something wrong here? Is something wrong with my board?

    I have tried running the fan at just about every frequency from 10-30,000Hz on F0 port and nothing seems to work. Oddly enough, at S0, the fan should be turned off, yet it still receives enough voltage to spin slowly without any force.

    I've tried reading up on some other related forum posts and haven't quite found a definitive solution, so I figured I'd ask here.



  • This will not fix the problem, but you can use the F parameter of M563 to change the fan mapping.

    For example, M563 P0 F1 would re-map fan1 to respond to fan0 g-code inputs while tool 0 is active. So you should be able to run the old g-code with no changes.



  • Can you post your config.g file, please?



  • @aidar 0_1550529015987_config.g

    Hope this helps, I'm sure there have been some mistakes in the making since i'm still growing into the Duet.



  • @nhof Interesting, I will keep that in mind if I can't solve the issue. Thanks for the tip!



  • Your config seems ok to me. Until you dont have something fancy in your config_override file it should work, If it doesnt i reccomend to check fan itself - connect it directly to psu to make sure it works. Then check all connections, specially F0 connector pins for bad solder. If fan works ok on other fan connectors and F0 connactor seems to be ok also but fan doesnt work on F0, then probably F0 mosfet is damaged.



  • @aidar The fan does indeed work on straight power and on other PWM fan ports. I've checked the F0 mosfet and it looks ok, no visible damage like darkening or melting. I snapped the "key" of the mosfet that locks in with the connector, but it doesn't prevent a solid connection.

    Is it possible I've blown some kind of fuse? Or would that cause more things to misbehave? I can't imagine when anything would have gotten damaged, but I suppose it's a possibility.



  • @hollywood0967 said in Tool Fan not working properly:

    Is it possible I've blown some kind of fuse?

    From your config i assume its Maestro. Maestro does not have onboard fuses that regular user can change. If fan works on other ports, then it must be F0 mosfet or connector. I think David or someone else from Duet3d will say what to do next, quick solution is to do what nhof reccomended, but in long terms board probably needs to repaire.


  • administrators

    It does sound to me that the Fan0 mosfet has failed.



  • @aidar It is indeed a Duet 2 Maestro. That is unfortunate that my mosfet shit the bed. I suppose I'll remap it to another port for now, and take another look at the board while i'm pulling it apart.


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