Fans and stuff improvements…



  • Okay so were always answering questions about fans and voltages, buck converters and PWM.

    Not a big problem but would it be possible in future revisions of the board to have fans independently powered by the voltage choice of the user. I appreciate having a jumper block for 5v, 12v (and a reg) and Vin (often 24v) would be quite cumbersome, but how about some sort of fan control IC which would allow fans voltage to be set from software?

    It would allow the use of the varied fans that people have lying around (also bear in mind not all fans are easily available in all voltages), think Noctua (very popular), but not easy to get in 24v. Might also mean less space taken up on the board if there exists some chip that can do 5v, 12 and Vin rails and PWM multiple fan outputs.

    Thoughts?


  • administrators

    Hi Simon

    Thanks for the suggestions, I will look into it when scoping future changes. Sounds like we would need an analogue mux or some switches in series to get the range of voltages at a reasonable current. I looked into some analog devices products for another project some time ago that might do it. It will add significantly to the cost though so it might be better if we get a range of 24V fans from nocua at a bulk price!

    P.s. moved to Hardware wish list



  • Thanks Tony, I think you could do a good trade stocking 24v fans, a large number of users are running 24v and these are the harder fans to source, plus people would, I'm sure, happily add a few fans to their order, it would be a relatively small add on.



  • I know its not the right thing to do, but I have been running Noctua's 12v vans off 24v PWM with zero problems. I agree though Noctua needs 24v fans and 30x30mm fans asap!!!



  • Our 5v 30mm blowers which are very versatile can be run on 12v but PWM'd to 25%-40% rather than 100% (they will handle 100% for a short while such as bridging). It's not really as problematic as it is with heaters, worst case scenario your fan dies, no fire, no drama except failed print or blocked nozzle.



  • I would also vote for this.

    I would like to check the status of the fans. For example, when I turn on the printer, I would like to check if all the sensors/fans are connected and ready to be read or not. Maybe one fan is unplugged and I want to detect this situation.

    In the case that the fan dies, this feature would avoid a failed print or blocked nozzle.



  • And my axe! On a side note, if adding a variable voltage regulator is too much then maybe a small screw terminal for the fan power supply? I'm currently feeding 12V for the fan selector on a 24V system, but I had to wire the big ones directly to the PSU - I'm afraid a single pin wouldn't be able to reliably handle the current otherwise.


  • administrators

    The main issue is that providing a 12V fan supply when the board is powered form 24V is the cost of the additional switching regulator. The Duet is already one of the more expensive 3D printer control boards, and we are reluctant to make it even more expensive.

    On a more positive note, I have been in communication with Noctua regarding 24V 40mm fans and 12/24V 30mm fans for 3D printers. They told me that they intend to add them to their range - but perhaps not until near the end of 2018.



  • Having the 12v select on the Duex5 has been awesome, but I'm thrilled to hear that Noctua will be looking at increasing their lineup, too.



  • A suggestion for next gen Duet then - add on fan modules with different voltage configurations to be available as accessories.

    EDIT. Come to that, you could take the existing voltage regulator off the board altogether making it cheaper for users who run everything at Vin, but have a connector or connectors that would accept an add on board (or boards) to step down the voltage for those that need it.



  • +1 for that, some sort of multifan add on module would be quite popular, something with Vin, 12v and 5v available, maybe even bus connected to the new duet system, so that you could attach maybe 6 fans at whichever voltage you wanted. Maybe native support for RPM monitoring for failed hotend fan etc..



  • @DjDemonD:

    +1 for that, some sort of multifan add on module would be quite popular, something with Vin, 12v and 5v available, maybe even bus connected to the new duet system, so that you could attach maybe 6 fans at whichever voltage you wanted. Maybe native support for RPM monitoring for failed hotend fan etc..

    Some sort of multi fan module as you describe would need to also facilitate fan mapping to heaters (virtual and real) as well as PWM control. So I'd have thought bus connected might be essential (but that's my line of expertise).



  • Have you considered making the next hardware release split into two or more models? One basic and one maxed out with all the possible bells and whistles? Seems anecdotally that the Duet brand is becoming really strong in the market place though I have no evidence to base the feasibility of this approach of course.


  • administrators

    Yes, we have. Expect an announcement next month - but we won't be announcing anything that supersedes the Duet Ethernet and Duet WiFi.



  • @dc42:

    Yes, we have. Expect an announcement next month - but we won't be announcing anything that supersedes the Duet Ethernet and Duet WiFi.

    Looking forward to it. It'd be nice to be able to use more than 10 steppers without using external drivers. It'd also be nice if I didn't have to run 20 conductors all the way from the Duet through cable chain to my 5 moving extruders but I' not holding my breath on that.


  • administrators

    More than 12 steppers won't be in next month's announcement; but we are working on it.


 

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