Enabling 2 fans for RAMPS

Hi. I have 1 hotend, 1 heatbed and 2 fans. How should I connect the fans on RAMPS 1.4(as hardware) and what should I change in Marlin so that the Hotend fan will run at full speed over 50 degree Celsius and turn off below 50 degree Celsius and the cooling filament fan or the prin fan to be turned off when it's not printing, 20% power on first layer, 70% power to the second layer and full power on the third layer. I took a look and there is no option in Malin for this. It's only EFB, EEF, EEB, EFF but no EFFB.

No opinion? Or is not possible.

Of course it is possible. But it is not a standard configuration and you will have to modify your pins_ramps.h file and make a couple of tweaks in Marlin_main.cpp

It is very difficult to offer suggestions when you have no idea about what is intended.

But remember... The RAMPS board only has 3 MOS-FET's. So if you want to control both fans independently of each other, you will need to do something special. Either add a MOS-FET driver, or put the fans in parallel.

You can get another MOS-FET driver board very cheaply here: [www.ebay.com]

Edited 2 time(s). Last edit at 03/16/2017 11:35PM by Roxy.

Ok, thank you. So After I buy another mos-fet driver board where should i wire the signal pin? I think the Vcc goes to 12V and Gnd to Gnd. And what should I change in Marlin after? I just want to have the hotend fan powered at full speed over 50 degree celsius and the print fan to respect the pwm signal from slicer. Now I have connected my print fan to D9 pin and I my hotend fan to 12Vcc. It's sucks because it's on all the time.