Multiple fan connections

Hello, I am just getting started with 3d printing & have been getting my materials & parts all lined out for a printer. I have the Sainsmart mega 2560 R3 with the ramps 1.4 with the A4988 drivers & the 12864 LCD. The question that I have is if I have one fan running to keep my ramps cool upon start up connected to the D9 terminals on the ramps where do I hook up another fan that I can control through the ramps or time delay for the hot end?. I've looked at the schematics and all over the webb & can't find any refrence for them. And yes with a handle like FarmerChuck i'm an old fart just getting started in 3D printing so either pin numbers or laymen terms, or a link to any article - page would be greatly appreciated. Thanks

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FarmerChuck
Hello, I am just getting started with 3d printing & have been getting my materials & parts all lined out for a printer. I have the Sainsmart mega 2560 R3 with the ramps 1.4 with the A4988 drivers & the 12864 LCD. The question that I have is if I have one fan running to keep my ramps cool upon start up connected to the D9 terminals on the ramps where do I hook up another fan that I can control through the ramps or time delay for the hot end?. I've looked at the schematics and all over the webb & can't find any refrence for them. And yes with a handle like FarmerChuck i'm an old fart just getting started in 3D printing so either pin numbers or laymen terms, or a link to any article - page would be greatly appreciated. Thanks

I use D9 for the controlled fan via slicer settings or M106 & M107 codes and for the always on fan use 12v off the RAMPS. Look for either 2 pins or 2 "through holes" on the board between where the X driver plugs in and the diode next to the smaller of the 2 square yellow fuses - that should be 12v.

Steve

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My updated Instructable on our Prusa i3 Build
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Yes. D9 should not be used for cooling the ramps itself. The output from that pin is under g code control and should be used for cooling the printed object. To cool the ramps itself, either take 12 volts directly from your psu or use the two pins near diode D2 as previously mentioned

If you plan to use an atx power supply with your printer then you can use any of the 12v or 5v
with or without a switch to power fans, lights or webcams as needed.

Gordon

OK, Thanks guys that helps a lot going forward knowing that when, not if I get stuck on something theres helpfull people out there willing to take the time to help. Thanks.

how is D9 gcode controlled ? i thought D9 was for a second extruder not a fan? also the 2 pin connection mentioned is for PS-on ability isnt it? if so, how is it able to be used for a fan location?

In the firmware you can specify what D9 is used for, either extra hot end or controlled fan.

Those 2 pins are directly connected to the ramps grnd and 12v supply. Theres no logic applied to them.
If youve got 12v supply connected the pin will be at 12v.

Gordon

As gordon says, you specify motherboard type in your marlin configuration. I think MB33 has D9 available as a fan port, and MB34 uses D9 for the second extruder. If you configure for a second extruder, note that there are no other available MOSFET circuits to connect a fan; you will need to put together a small circuit yourself to connect a fan.

how exactly can i use D9 for a fan? i cant find it in the Marlin FW... is it in the config...h tab? i have MB33 selected and running...

Use M106 and M107. See here.