Jump to content
UltiMaker Community of 3D Printing Experts

Spitting out filament at start of print


Recommended Posts

Posted · Spitting out filament at start of print

Hi all,

I just started using Cura with my MendelMax and the first print turned out great. The second print, however, yielded a strange problem. I loaded and sliced this object to gcode:


It's a 5mm calibration blocks test that I'm sure many of you know and love/are completely sick of.

Anyway, I sliced this and loaded the gcode to Pronterface, just as I did with the first attempt at using Cura. However, on printing, the extruder ran in reverse and very quickly pushing the filament all the way back out of the extruder immediately upon starting the print. The printer homed the axes, then reversed out the filament.

I turned off the retraction feature in Cura and tried again. This time it reversed only a few mm such that the material started coming out again not long after the skirt had been drawn out.

Anyone seen anything like this, and what else can I share to help?




  • Link to post
    Share on other sites

    Posted · Spitting out filament at start of print

    Something about the start gcode isn't working, so that it isn't resetting the extruder position. At the start of the print, it zeros the extruder position, then extrudes a few mm of filamant to prime the head, then resets the extruder position to zero, then starts printing.

    The initial 'zero the extruder' isn't working, so that when it tries to move the extruder to its 3mm position (from zero, hence extruding 3mm of filament), it instead thinks you want to go to the 3mm position from whatever position you are at, and so runs the extruder backward to where it was 3mm into the previous print.

    Are you running Marlin firmware on your printer?

    Can you post the first few lines of a sample gcode, up to the point where it starts the skirt lines?


  • Link to post
    Share on other sites

    Posted · Spitting out filament at start of print

    I recommend maybe power cycling your printer Arduino before printing. Like Illuminarti says, it's probably remembering the position where you last printed and backing back up to the beginning with the extruder and doesn't know that that filament is gone now.


  • Link to post
    Share on other sites

    Posted · Spitting out filament at start of print

    Thanks. I am using Marlin, though I've never needed to power cycle the printer. I've been using Slic3r for some time and never had this issue. Here's the start of the gcode:

    ;Generated with Cura_SteamEngine 13.11.2

    M140 S65.000000

    M109 T0 S180.000000


    M190 S65.000000

    ;Sliced at: Sun 01-12-2013 08:19:13

    ;Basic settings: Layer height: 0.2 Walls: 1 Fill: 30

    ;Print time: #P_TIME#

    ;Filament used: #F_AMNT#m #F_WGHT#g

    ;Filament cost: #F_COST#

    ;M190 S65 ;Uncomment to add your own bed temperature line

    ;M109 S180 ;Uncomment to add your own temperature line

    G28 ; home all axes


    ;Layer count: 125



    G0 F5940 X100.95 Y108.75 Z0.30


    G1 F2400 E0.00000

    G1 F1140 X109.05 Y108.75 E0.19062

    G1 X111.25 Y110.95 E0.26366

    G1 X111.25 Y113.75 E0.32959



  • Link to post
    Share on other sites

    Posted · Spitting out filament at start of print

    Add "G92 E0 ;zero the extruded length" to your start.gcode. Cura doesn't automagically insert that like other slicers tend to do. If you don't reset the extruder postion, first extrude command in the gcode will end up reversing the filament on your second print.

    Ask me how I know that. ;-) Scratched my head for a while before realizing this one.


  • Link to post
    Share on other sites

    Posted · Spitting out filament at start of print

    It looks like you're not using any start gcode at all - just a single G28, so you aren't resetting the filament length as amramsey says.

    Here's the standard start gcode that you can enter in the Start/End-Gcode tab:

    G21 ;metric values

    G90 ;absolute positioning

    M107 ;start with the fan off

    G28 X0 Y0 ;move X/Y to min endstops

    G28 Z0 ;move Z to min endstops

    G1 Z15.0 F{travel_speed} ;move the platform down 15mm

    G92 E0 ;zero the extruded length

    G1 F200 E3 ;extrude 3mm of feed stock

    G92 E0 ;zero the extruded length again

    G1 F{travel_speed}

    ;Put printing message on LCD screen

    M117 Printing...


  • Link to post
    Share on other sites

    Posted · Spitting out filament at start of print

    Thanks, all. This was super helpful and solved my problem. I guess I got a little carried away deleting the standard start script :oops:


  • 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

      • 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
        • 13 replies
      • UltiMaker Cura 5.3.0-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
        • 17 replies
      • New here? Get ahead with a free onboarding course
        Often getting started is the most difficult part of any process. A good start sets you up for success and saves you time and energy that could be spent elsewhere. That is why we have a onboarding course ready for
        Ultimaker S5 Pro Bundle, Ultimaker S5, Ultimaker S3 Ultimaker 2+ Connect.   
        They're ready for you on the Ultimaker Academy platform. All you need to do to gain access is to register your product to gain free access. 
        Ready? Register your product here in just 60 seconds.
          • Like
        • 14 replies
    • Create New...