Slic3r settings for dual head setup

Hi, I would like to switch from cura to slic3r because for large complex prints(20-29hrs) I think I can benefit from the more advanced options in slic3r:

  • different layer hights for complex and less complex sections of the part
  • more options for infill

Are there benefits in keep using the repetier host, or better swith to slic3r as stand-alone program? From what i’ve seen already is that the preview functions in slic3r are similar to repetier.
One thin I can’t figure out is to tell slic3r to use extruder 2(from repetier host), although configured in slic3r.

Has anyone done some pioneering work in this (probably yes but search function didn’t turn out the info I’m looking)?

  • bed shape 200*180?
  • extruder offset need to be set?
  • start and end g-code?

I have no experience trying to use slic3r outside of Repetier, but I think this may help:

Bed size is set to 200x200x190.
The extruder offset is set in firmware, so the firmware should be able to figure it out, regardless of software.

Start GCode:

G28 ; Home extruder
G1 Z5 F{Z_TRAVEL_SPEED}
G1 Z0 F{Z_TRAVEL_SPEED}
M106 S165 ; Turn on fan
G90 ; Absolute positioning
M82 ; Extruder in absolute mode
; Activate all used extruder
M104 S{TEMP}
G92 E0 ; Reset extruder position
; Wait for all used extruders to reach temperature
M109 S{TEMP}
M83
G1 E10 F100
M82
G92 E0 ; Reset extruder position
M117 Vertex is printing  
G1 F1000 Z5

End GCode:

; Default end code
;G1 X0 Y0 Z130 ; Get extruder out of way. Uncomment to use!
M107 ; Turn off fan
; Disable all extruder
G91 ; Relative positioning
{IF_EXT0}T0
{IF_EXT0}G1 E-1 ; Reduce filament pressure
M104 T0 S0
{IF_EXT1}T1
{IF_EXT1}G1 E-1 ; Reduce filament pressure
M104 T1 S0
G90 ; Absolute positioning
G92 E0 ; Reset extruder position
M140 S0 ; Disable heated bed
M84 ; Turn steppers off
T0
T1
T0

Pre extruder change GCode:

M106 S165 ; Turn on fan
G1 F5000 X0
G1 F5000 Y100
;BEFORE EXTRUDER SWITCH

Post extruder change GCode:

;AFTER EXTRUDER SWITCH
M106 S165 ; Turn on fan
M104 S{TEMP}
M109 S{TEMP}

I don’t think the start and end gcode can be copied from the cura settings. slic3r doesn’t seem to accept arguments being passed.
Main issue with the slic3r being initiated from repetier is that the extruder selection is apparently lost.

When I slice from slic3r as stand-alone you can select the extruder and gcode is correct (M109 T0 or T1) xxx
Main limitation of slic3r as stand alone is you don’t have the gcode previewer. You can however load the gcode from the stand-alone slic3r into repetier; where it’s reassuring to see that the object fits nicely onto the platter and you can preview the gcode line by line.

but still need to do the first actual prints via this system

prints are ok with the standard slic3r start and end code. To my experience I can benefit from the extra slicer options.
Small downside is that you need to load the gcode file into repetier to inspect the gcode and verify placement on the bed.