rambo fan headers

I noticed that the Rambo has two Molex connectors available for fans
when i try and use them, there is no power available
is there a way to turn these on
and control the fan speed in a slicer (simplify3d)

In the Marlin pins.h file, for your motherboard type you need to have FAN_PIN defined to the MEGA processor pin RAMBO uses for the fan header you'd want to use. Then in Simplify3D, the fan would be controlled through the COOLING process tab. There you can set up turning it on after the first layer, etc. There's also a fan speed slider control on the machine control panel.

There might actually be three fan outputs. The schematic shows MOSFET Q8 controlling FAN-2 on connector X9, although the board layouts on RAMBO page on the reprap wiki don't seem to show either Q8 or X9. Having six MOSFETS to control things on RAMBO is a definite advantage over the four available on RAMPS.

Looking at the RAMBO schematic, MEGA pin 8 is used to control FAN 0; pin 6 controls FAN 1; pin 2 controls FAN 2.

BTW, info on using Marlin's auto-fan function for controlling the extruder fan was mentioned in http://3dprintboard.com/showthread.p...pdating-Pins-h. This would allow Marlin to keep the extruder fan off and quiet, for example, while the extruder is around room temperature.

you can turn on the fan 0 with m106 command if you havent modified the pins configuration . im currently have the extruder fan automatic so it turns on when the extruder reach 50c . in order to do this you will need to disable fan pin number 8 under pins config

For the extruder autofan function. :

Set EXTRUDER_0_AUTOFAN_PIN to 8

Under configuration adv

In pins.h:
Set FAN_PIN to -1 to disable old FAN_PIN usage

This will automatically turn the fan on when the extruder reach defined temperature

also the FAN 1 i belive is pin 7 can be use to cool the motors or cooling the print .

Source:
http://wp.boim.com/?p=97

fan1 is pin 6
fan2 is pin 2