Jump to content

Settings in a customized firmware doesn't work no matter how I change it


Recommended Posts

Posted · Settings in a customized firmware doesn't work no matter how I change it

Hi friends,

Please help! I cannot make my settings in the customized Marlin firmware work. Here's my story:

I'm using a UM2. I was going to change the


parameter to make the fast forward length shorter, otherwise I found the filament was reaching the nozzle at a very high speed, which constantly causes heavy filament grindings.

So I download the source code from the official github: ultimaker2marlin, found the file UltiLCD2_menu_material.h and changed the


in the file from





Then I compiled the firmware by following the knowledge I've got so far: with Arduino, commenting out the


part in twi.c, compiled it and uploaded the .hex file by using Cura 15.04. I was sure for the successful firmware update because I saw the version changed to my customized one in the LCD menu.

But the forward length seemed not changed at all. Grinding happened as before. So I changed FILAMENT_FORWARD_LENGTH to (Bowden_length - 150). Again, no visible difference was shown. The fast filament feeding still went like nothing was changed.

To understand what was happening I used G-code G1 E-100 in printrun, and measured the outgoing filament. I found the outgoing length was almost 200mm, twice as it should be! I thought that might be the reason, perhaps every length was doubled, therefore even (Bowden_length - 150) were still longer than the actual length of bowden tube because of this doubling!

I thought the reason for doubling was the wrong setting in the configuration.h: I found the DEFAULT_AXIS_STEPS_PER_UNIT for extruder was 282, which I thought should be 125 or so since I had a φ8.1 feeder wheel (if I did the math right). Then I changed it to 125, expecting the 100mm feeding length instead of 200.

But after uploading my changes, nothing changed. The G-code feeding G1 E100 (or -100) is still 200mm filament in output.

So it turns out nothing have changed no matter how I was tweaking the settings in Marlin. So I'm totally confused! Did I did something silly? Does anyone use a customized firmware? Any clues will be appreciated ! Thanks!



  • Link to post
    Share on other sites

    Posted · Settings in a customized firmware doesn't work no matter how I change it

    Thanks very much! That's exactly what I'm looking for!


    So  - you changed the default settings and compiled it into your firmware. That's not wrong, but those settings are stored in eeprom and can be changed via gcode commands.

    The new defaults will only be used after a "Factory reset"...


  • 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

      • S-Line Firmware 8.3.0 was released Nov. 20th on the "Latest" firmware branch.
        (Sorry, was out of office when this released)

        This update is for...
        All UltiMaker S series  
        New features
        Temperature status. During print preparation, the temperatures of the print cores and build plate will be shown on the display. This gives a better indication of the progress and remaining wait time. Save log files in paused state. It is now possible to save the printer's log files to USB if the currently active print job is paused. Previously, the Dump logs to USB option was only enabled if the printer was in idle state. Confirm print removal via Digital Factory. If the printer is connected to the Digital Factory, it is now possible to confirm the removal of a previous print job via the Digital Factory interface. This is useful in situations where the build plate is clear, but the operator forgot to select Confirm removal on the printer’s display. Visit this page for more information about this feature.
          • Like
        • 0 replies
      • Ultimaker Cura 5.6 stable released
        Cura now supports Method series printers!
        A year after the merger of Ultimaker and MakerBotQQ, we have unlocked the ability for users of our Method series printers to slice files using UltiMaker Cura. As of this release, users can find profiles for our Method and Method XL printers, as well as material profiles for ABS-R, ABS-CF, and RapidRinse. Meaning it’s now possible to use either Cura or the existing cloud-slicing software CloudPrint when printing with these printers or materials
        • 48 replies
    • Create New...