5V fan-suitable output on RAMPS


Hi guys,
I have a little issue here… :smiley:
A few months ago, I bought a very expensive Noctua 40mm fan, convinced that I need the 5V version and now, wiring my board I notice that everyone hooks his fan up to a 12V pin.
Would it be possible to just use one (or multiple if that makes any difference) of the Servo pins? According to this schematic: https://reprap.org/mediawiki/images/c/ca/Arduinomega1-4connectors.png they all deliver 5V.
The maximum input power for the fan is 0.25W and as I said it’s 5V, so the pins would only need to be able to deliver 50mA. Don’t know if it’s too much or if it’s fine.
A quick check with the multimeter gave me a reading of ~0V though, so I suppose you need to set them to “1” via Firmware - any information about these pins would be great!
Thank you in advance!


First of all to get 5V on the servo pins you have to set the VCC GND jumper on the RAMPS. If I remember correct the recommended continious current on an outpot pin for the Arduino and thats where your servo pins are powered from is 20mA with an max of 40mA. The overall current drawn if the Arduino is powred trough USB should not exeed 500mA.
I personally even had issues with a BL Touch clone powered on the 5V VCC. So my recommendatio would be to take an 2-3€ 12-5V buck step down converter instead of powering from the Ramps Servo pins


The 5V version is only needed on the einsy board.