Dual extruders on a RAMPS clone with 4 power outputs

I own a printer that uses a RAMPS clone with 4 power outputs labelled E0, E1, Fan and Bed. I see there are other RAMPS clones with a similar design.

I'm trying to set up the Configuration.h correctly, and the first hurdle is the '#define MOTHERBOARD' statement.

The relevant options in boards.h are as follows:

BOARD_RAMPS_14_EFB // RAMPS 1.4 (Power outputs: Extruder, Fan, Bed)
BOARD_RAMPS_14_EEB // RAMPS 1.4 (Power outputs: Extruder0, Extruder1, Bed)
BOARD_RAMPS_14_EFF // RAMPS 1.4 (Power outputs: Extruder, Fan, Fan)
BOARD_RAMPS_14_EEF // RAMPS 1.4 (Power outputs: Extruder0, Extruder1, Fan)`
BOARD_RAMPS_14_SF // RAMPS 1.4 (Power outputs: Spindle, Controller Fan)`

These all seem to cater to the original RAMPS board with only 3 power outputs. Which should I use? The 'EEB' version seems best for dual extruders, but will I then lose control over the fan output?

As you say ramps only has 3 mosfets and thus all standard RAMPS configurations will not work for you. you loose the last mosfet

From googling this board you should set the motherboard type to MKS_BASE

This defines the extra mosfet but is otherwise identical to ramps pin out wise.

This set the configuration to EFBF or EFBE (ie is setup so E1 or Fan 1 commands can control this last mosfet)

info from here [github.com] (warning, information/whingeing content is very low)

Edited 2 time(s). Last edit at 03/19/2017 02:12AM by Dust.

Thanks, that helps a lot. I also had to switch to the RC version of Marlin, as the stable release doesn't have the MKS definitions.