(sorry if this has already been discussed, I searched but...)
I have a 3 head printer and multi-head printers are becoming (already are?) the norm rather than the exception. When mono-head printers were the norm, putting the retraction settings under "printer" and associating them with the extruder/hotend made sense, but now with multi-heads so common I think this should be re-evaluated.
As I see it, the four items most effecting the Retraction settings are: nozzel size, hot end type (and quality), temparture, and filament type (and quality).
Temparture is already associated with filament settings.
The type and quality of the filament has the most variability and, arguably, the most influence. On multi-heads, slic3r already allows filament size to be indevidualy set for each filament (which, arguably, is a printer or at lest an extruder setting). If nozzel size were also associated with the filament setting then the retraction settings could be as well, resulting in a more logical (and convienent!) grouping.
Right now, if I switch filament (or tempature), I need to make changes in two places, worse, there is no way to associate the retraction settings with the filament which means if I switch the same filament from one extruder to a different extruder not only do I have to change my printer settings but I have to (manualy) change retraction settings for
both extruders (the original and the re-assigned).
By contrast, if nozzel and retraction settings were associated with each filament, I could develop a library of filament profiles and changing filament (either between nozzles or with a different filament) would be as simple as selecting a different profile from a single menu.
-V
