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Auto contol of non part fans

Discussion in 'Mods and Upgrades' started by Xmodgeek, Jan 25, 2018.

  1. Xmodgeek

    Xmodgeek New Member

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    Hello, I'm trying to keep idle noise and fan wear to a minimum. I just added a E3d V6 Lite hotend and replaced the other fans as the bushings have gone bad on my R1+... the worst is in the PSU itself that I haven't pulled apart yet.

    Anyways I want to be able to turn on the hotend fan only when it's on (say above 50c) and only have the fan on over the stepper drivers when the motors are active.

    I've seen this, and it looks promising. But I have no idea what the pin outs are for FAN1 and FAN2. All I can find is FAN_PIN = 9 but that's just the part fan...
    (I had a link here to some one with a similar request but it wouldn't let me post because I guess it thought I was posting spam?(Oh I now see the bar that says a minimum of 3 posts.... Oh well))

    If anything I'd just like to be able to control the hotend fan as that code looks to already be in there. I can just put a 'normal' PC fan on the main board that would be quieter and hopefully last longer.

    Thanks
     
  2. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    You would need to move the hotend fan to another pin. It is currently on 100% of the time as it is directly connected to a +12V set of pins. It is that way for safety reasons. Then once moved you will need to drive the fan with a MOSFET because the other pins do not allow enough power draw without one. After that you will need to include code in your start up G-code and ending G-code to control turning the fan on and off.

    For one fan it seems like a lot of hoops to jump through.
     
  3. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Also (sadly) in order to best do this you want to grab a spare I/O pin on the RAMPS. The standard RAMPS would have some, the R1+ version ... has most of the spare pins removed. So you would want to consider swapping to a standard RAMPS as well ... there is a thread on that at least :)
     
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  4. Xmodgeek

    Xmodgeek New Member

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    I see... I was afraid of that. Well I guess that's a better setup then just wiring the fans into the 12V from the PSU. But man I wish there was more documentation of the R1+ board.

    Yeah I get that I'd have to do all that then I was just thinking since the headers were on the broad and labeled FAN1 and FAN2 they were controlled. I'd prefer to see them labeled as +12V or something. I'm guessing the LEDR and LEDL are the same?

    The link I couldn't post shows the settings to change for auto hotend fan.

    upload_2018-1-26_13-38-48.png

    Can I not solder to the stub on the board to get the digital out?

    But realistically it's going to be more work then I'd probably want to put into it right now. It will have to wait until I change out the PSU fan and figure out how to make the whole thing 'soft' power on.
     
  5. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    You can use a different digital pin and specify it where the -1 (-1 equals not available) is. But you still need to drive it with sufficient power. The digital pins do not have that since they only provide +5V. The existing fan connectors on the board might be connected to a digital pin and powered through a MOSFET, I doubt it is, but I am not familiar with the R1+ mainboard wiring.
     
    #5 WheresWaldo, Jan 26, 2018
    Last edited: Jan 26, 2018
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  6. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Nobody really is :) However I would back your original supposition :

     
  7. Xmodgeek

    Xmodgeek New Member

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    What? I can't power it off the MCU output??? They should make all outputs handle that much power... Na yeah I get it. Although it's good to know it's only +3v but most FETs I try to use lately are good to 1.8v gate voltage.

    Next time I crack open the bottom of the printer I'll take a harder look. I was surprised of lake of info on the board. I thought I could just look it up.
     
  8. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    If you want to use it to drive a MOSFET -- no worries. It will do that.
     
  9. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    I changed my post above it is +5V on the Digital pins. The real limit is that the pins themselves can only sink 40 mA.
     
  10. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    If you enable PINS_DEBUGGING you can see which pins are in use with an M43 command. It is in Configuration_adv.h near the end of the file.
     
  11. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
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    There is another way of doing this. If you get a Fan Extender it connects to what would be AUX-1 and gives you control of fans on 4 and 5. You would have to move a few wires and may need to add pin headers to AUX-1.
     
  12. albert3d

    albert3d Member

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    What you want to do is install an RRD Fan Extender. There is a post if you search for RRD on this forum by someone named @danzca6 , but I am too new here to be able to post links either. It has what pins are needed and what firmware bits are needed.
     

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