Dual extruder steps

[Tattered]

Hi.

I don't understand how to calibrate dual extruders. I would like to print a different support material so the steps on my extruders will be different.

I am using geetech prusa i3 pro B, GT2560, marlin pro B, arduino 1.0.1. slic3r and repetier host

I understand how to do marlin, define extruder, etc. I just dont know how to add steps for the second extruder.

//// MOVEMENT SETTINGS
#define NUM_AXIS 4 // The axis order in all axis related arrays is X, Y, Z, E
#define HOMING_FEEDRATE {50*60, 50*60, 4*60, 0} // set the homing speeds (mm/min)

// default settings

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2560,534} // MXL, Z M8=1.25, Geared Nema .4mm nozzle
#define DEFAULT_MAX_FEEDRATE {400, 400, 2, 45} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {5000,5000,50,5000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

I can change the extrusion multiplier in repetier host but its hard to be accurate and I would prefer it to be in marlin.

[William]

Maybe you can refer to the firmware for Pro C:
http://www.geeetech.com/forum/viewtopic ... 20&t=17046