Jump to content
UltiMaker Community of 3D Printing Experts

Help Required For Calling CuraEngline From Python For Command Line Tool


Recommended Posts

Posted · Help Required For Calling CuraEngline From Python For Command Line Tool

I am trying to build a command line application that converts a given stl file into gcode and launches the print automatically. For this, I write the code in Python, and use CuraEngine and Printcore:

import subprocess

import xmlrpclib

import sys

import time

from printrun.printcore import printcore

from printrun import gcoder

curaEngine = "C:/Desktop/CuraEnginePacket/CuraEngine"

JSONfile = "C:/Desktop/CuraResources/machines/ultimaker2plus.json"

myGcode = "C:Desktop/mygcode.gcode"

myStl = "C:/Desktop/XX.stl"

p = printcore('COM6', 250000)

command = [curaEngine, 'slice', '-j', JSONfile, '-o', myGcode, '-l', myStl]

return_code = subprocess.call(command)

gcode = [i.strip() for i in open(myGcode)]

gcode = gcoder.LightGCode(gcode)


When I tested the program, it started the print, but the printer head was just moving back and forth and no material came out of it. As a check, I loaded my stl-file in Cura, and compared the resulting gcode to the one generated by CuraEngine. Surprisingly, they did differ to a huge extent. The -- START GCODE -- and -- END GCODE -- sections were not included in the gcode created by CuraEngine, furthermore the coordinates were slightly different as well.

Have I called CuraEngine correctly in Python? How could I make my program add the missing sections to the gcode?

Thanks a lot for your attention to the problem!

  • Link to post
    Share on other sites

    Posted · Help Required For Calling CuraEngline From Python For Command Line Tool


    I have basically the exactly same issue since i am working on something related.

    You have to download and compile the latest CuraEngine version. This one does output the gcode header after the file has been sliced. You then need to process the output of CuraEngine, extract the last bit with the new gcode header and replace the gcode header in your .gcode file with it.

    There are TONS of slicing parameters which CuraEngine supports. If you don't specify any, you get the minimal default which is not really what you want.

    In order to get a proper list of parameters I suggest you do the following:


    1. Use Cura Desktop 2.3.0 to slice a model the way you like it.
    2. Take a look at the cura.log file to see which slicing parameters Cura Desktop used to slice it (since Cura Desktop acts as a very sophisticated frontend for CuraEngine it sends all slicing options in one go (every parameters prepended by "-s")). On my Mac the cura.log file resides at ~/Library/Application Support/Cura/cura.log
    3. Save the slicing parameters to a text file and append its contents to your CuraEngine call.


  • Link to post
    Share on other sites

    • 1 year later...
    Posted · Help Required For Calling CuraEngline From Python For Command Line Tool

    Hi NicoLinux,

    I have been trying to capture the filament length and time from the, "Gcode header after slicing". But apparently, the updated header does not show up in the output for the command

    `CuraEngine slice -v -p -j fdmprinter.def.json -l #{model_url}`

    Seems the header is generated after the gcode, which is not captured in the output.

    How could I get the final, filament and time parameters.


  • Link to post
    Share on other sites

    Posted · Help Required For Calling CuraEngline From Python For Command Line Tool

    Hi rapcsak, did you manage to get the code working. I am trying to do the same thing, so it would be nice to know if this might work or not.

  • Link to post
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
    • Our picks

      • UltiMaker Cura 5.3 stable released
        In this stable release, Cura 5.3 achieves yet another huge leap forward in 3D printing thanks to material interlocking! As well as introducing an expanded recommended print settings menu and lots of print quality improvements. Not to mention, a whole bunch of new printer profiles for non-UltiMaker printers!
          • Thanks
          • Like
        • 31 replies
      • Here it is. The new UltiMaker S7
        The UltiMaker S7 is built on the success of the UltiMaker S5 and its design decisions were heavily based on feedback from customers.
        So what’s new?
        The obvious change is the S7’s height. It now includes an integrated Air Manager. This filters the exhaust air of every print and also improves build temperature stability. To further enclose the build chamber the S7 only has one magnetically latched door.
        The build stack has also been completely redesigned. A PEI-coated flexible steel build plate makes a big difference to productivity. Not only do you not need tools to pop a printed part off. But we also don’t recommend using or adhesion structures for UltiMaker materials (except PC, because...it’s PC). Along with that, 4 pins and 25 magnets make it easy to replace the flex plate perfectly – even with one hand.
        The re-engineered print head has an inductive sensor which reduces noise when probing the build plate. This effectively makes it much harder to not achieve a perfect first layer, improving overall print success. We also reversed the front fan direction (fewer plastic hairs, less maintenance), made the print core door magnets stronger, and add a sensor that helps avoid flooding.

        The UltiMaker S7 also includes quality of life improvements:
        Reliable bed tilt compensation (no more thumbscrews) 2.4 and 5 GHz Wi-Fi A 1080p camera (mounted higher for a better view) Compatibility with 280+ Marketplace materials Compatibility with S5 project files (no reslicing needed) And a whole lot more  
        Curious to see the S7 in action?
        We’re hosting a free tech demo on February 7.
        It will be live and you can ask any questions to our CTO, Miguel Calvo.
        Register here for the Webinar
          • Like
        • 18 replies
      • UltiMaker Cura Alpha 🎄 Tree Support Spotlight 🎄
        Are you a fan of tree support, but dislike the removal process and the amount of filament it uses? Then we would like to invite you to try this special release of UltiMaker Cura. Brought to you by our special community contributor @thomasrahm
        We generated a special version of Cura 5.2 called 5.3.0 Alpha + Xmas. The only changes we introduced compared to UltiMaker Cura 5.2.1 are those which are needed for the new supports. So keep in mind, this is not a sneak peek for Cura 5.3 (there are some really cool new features coming up) but a spotlight release highlighting this new version of tree supports.  
          • Like
        • 25 replies
    • Create New...