0xBeFa

Ok I will make some tests with Makerbot flavor. The extruder G-code is clear to me, I was talking about these settings under the experimental section:

In the machine settings I have set the G-code flavor set to RepRap. I don't really know what the difference between Marlin, RepRap or Makerbot is. My printer has Sailfish firmware. I'm also confused about the start g-code. In the machine settings dialog there is one field for start g-code and under print settings I have enabled the "code for single extrusion" and "code for dual extrusion" fields. The print setting fields contain different start routines for single or dual but they are not used. Instead the start code from the machine settings is used which is dual start code. Where is the correct place to edit the start g-code?

I am using a Qidi Tech 1 dual extruder printer with a custom profile made for the Flashforge Creator Pro (which seems to be exactly the same printer). I noticed that for the first layer sometimes the wrong extruder is used. So if Cura starts on the first layer with the support material (which I set to the right extruder) the printer pushes filament trough the left nozzle which is set to the standby temperature. The right nozzle is heating correctly but not extruding. For subsequent layers the extruder switch is working as expected. My start G-code ends with following lines: G92 A0 B0 ; zero extruders M135 T{initial_extruder_nr} ; left or right tool M73 P1 ;@body (notify GPX body has started) ; **** end of start.gcode **** Apparently the variable {initial_extruder_nr} is not set correctly. At the moment I'm applying a workaround where I looking at the first layer after slicing and if it starts with the right extruder I use the search and replace post processing plugin to manipulate the G-code: Search: M135 T1 ; left or right tool Replace: M135 T0 ; left or right tool Is this a bug in Cura or is there something wrong with the printer profile?

Is there a trick to set up cura that only the top and bottom layer of the support interface is printed with a different extruder? For example I want to print PLA and BVOH with 3 layers support interface like this: BVOH interface 3 (100%) PLA interface 2 (100%) PLA interface 1 (100%) multiple PLA infills (20%) PLA interface 3 (100%) PLA interface 2 (100%) BVOH interface 1 (100%) With the current settings I can only achieve: BVOH interface 3 (100%) BVOH interface 2 (100%) BVOH interface 1 (100%) multiple PLA infills (20%) BVOH interface 3 (100%) BVOH interface 2 (100%) BVOH interface 1 (100%) The problem with that is that the layer adhesion between PLA and a soluble support material like PVA or BVOH is not as good as the layer adhesion of PLA+PLA or the soluble material with itself. So trying to lay down 100% support material on 20% PLA will more likely fail than on a solid PLA base. This settings would make mixed material support much more applicable and there are many advantages to do so: save money for specialized support materials like Breakaway or BVOH less material that needs to be dissolved depending on the model the number of extruder switches can be reduced by >90% --> better print time, less chance of clogging, less oozed out material