This a printer definition and set of quality profiles for the Original Prusa i3 Mk2, for use with
the new Cura 2.3 beta configuration style. The definition needs to be placed in the
cura/resources/definitions/ directory in your Cura 2.3 installation.
Please see the Quality Profiles section for more information on those presets.
On Mac OSX this location is found inside the Application Bundle itself, and the resources directory
lives in /Applications/Cura.app/Contents/Resources/cura/resources. Cura must be restarted for the new
printer definition to be available.
The shared config files are stored in ~/Library/Application Support/cura.
On Windows this location depends on where you installed Cura, but by default it will be located at
C:\Program Files\Cura 2.3\resources. The same applies concerning restarting for the new definition
to be available.
The shared config files are stored in %AppData%\Local\cura.
There is a bug in the new 2.x Cura versions where it misbehaves in odd ways if you have the shared config files from the legacy versions of Cura on your system. You cannot currently run the legacy Cura, then the new Cura, without first removing these old files and restarting the new Cura.
Since the current Cura 2.3 beta does not provide access to the huge number of settings available
in the new printer definitions, I decided to make my own for my Original Prusa i3 Mark 2. I had to
override quite a few of the default values which are inherited from the base fdmprinter.def.json
definition.
I set some of the parameters based on the Slic3r quality settings provided by Prusa Research, such
as the initial layer height of 0.15mm. Most of the rest of the settings were pulled from my EEPROM
defaults, which I have not changed. They are current as of firmware 3.0.8.
For the starting gcode, I came up with a mixture of steps to accomplish several things:
- Most importantly, CuraEngine only uses absolute positioning and extruding values. So I use M82 to set absolute extrusion mode.
- I adopted the extruder and bed pre-heating steps from Slic3r because Cura's automatic ones make you wait for one, then the other, which takes unnecessary time. If you provide your own temp codes, it doesn't generate any for you.
- I added an absolute version of the off-print-area steps to draw two thick lines to "wipe" the nozzle and clear off any lingering filament before beginning the print.
- I chose to perform the Mesh Bed Leveling routine prior to heating the extruder and bed, in hopes of less oozing filament being drug around the bed by leveling after heating completes.
- Lastly, surrounding the wiping steps are some explicit extrusion distance resets, since we're using absolute extrusion now and don't want to confuse the print code since Cura won't know about our extrusion for wiping.
The ending gcode is pretty stock, probably lifted from Slic3r or Simplify3D.
Cura 2.3 comes with 3 stock profiles for different print qualities. This printer definition has nothing to do with them except for the initial layer height. I thought it was reasonable to at least provide a default from the printer that would allow you to print successfully with the rest of the stock profile settings unchanged.
I did attempt to translate the main Slic3r profiles into Cura equivalents as well, which are in the quality directory. There's instructions there for where to put the files, as well.
One thing to keep in mind, though, is that the stock profile speed settings are 30-50% faster than the Slic3r profiles. I've had pretty decent results even at the higher speeds, but you might want to turn them down or use the "high power" mode through the LCD menu if you experience quality issues at these higher speeds trying to use the stock profiles.
I measured the bounding box of the extruder assembly (fans included) as best I could, as well as setting the gantry height to my best measurement from the bottom X carriage bar to the nozzle tip. These dimensions only matter if you use the "One At A Time" printing mode, but because the gantry and extruder assembly are relatively short/large respectively, your print height and model clearances will be very constrained. Nonetheless, I believe these values are within a mm or two.
One last thing to consider is that I wasn't able to characterize the impact of the fact this extruder assembly has its wiring harness protruding from very near the bottom of the back of assembly, which has a high likelihood of crashing into models if approaching them from the front. Whether this matters or not is up to you.