Jump to content

Feature Request: multi-extruder, single nozzle, without prime tower


Recommended Posts

Posted · Feature Request: multi-extruder, single nozzle, without prime tower

The motivating problem: I have recently experienced frustrating print failure at near-completion of a large, tall 2-color PLA print on a Creality CR-X (2 extruders, 1 hotend)—the problem is that even with a large prime tower footprint, when it gets tall (200-300mm), the torque from the printing pries the prime tower loose while adding layers.  Also, it is extremely wasteful of material.  


The solution (a new feature): It occurred to me that the prime tower would be completely unnecessary if the G-code would instruct the machine to perform filament switch before finishing one color so as to push the leftovers out on that same color, and then prime the next color into the interior of the part, for example fill or inner walls.  In this way, the primings are integral to the object being printed, resulting in zero waste and more robust printing.  This feature could be implemented in Cura with perhaps a checkbox and 2 parameters (the length to continue extruding after filament change and the volume to prime, which is already a parameter) and some programming to sequence the operations near a filament change.  There may also be the need for a feature that warns the user if there is not enough infill or inner wall to handle the desired priming volume.


Best Regards and thanks for the sweet software!


  • Link to post
    Share on other sites

    Posted · Feature Request: multi-extruder, single nozzle, without prime tower

    That's interesting but you run the risk of the part being knocked over when the priming is done on the inside and the printhead is wiped against the inner walls. Or to have small bits of filament sticking out of your part and messing up the layers and the coloring, in case the priming isn't perfect and tehre's still some leakage.


    It's been suggested to UM to make the prime tower conical: wider at the base and thinner at the top, to give it even more stability with the round shape, I do not know if this is on their todolist and would be implemented in Cura 4.0 or later, or maybe it is on list of things that would be nice to code but are not considered that important.



  • Link to post
    Share on other sites

    Posted · Feature Request: multi-extruder, single nozzle, without prime tower

    Thank you, Brulty.  I appreciate your points on that.  I have found that this issue of oozing can be easily addressed as follows.  At extruder switch, active extruder is retracted 100 mm by setting position to -100.  Then tool is switched to next extruder and instead of setting position back to 0 (thus reversing the complete 100mm retraction), the position can be set to -5 so that there is no oozing.  Then the risk is only of missing a small bit of material on the infill, which I do not forsee to be a problem.  The machine already retracts and de-retracts many times during a print.  An extruder switch would be no different.  Of course, this would not be universally applicable to every conceivable print, but gosh would it save a lot of waste material from the environment and save a lot of headache with failed prints.  In my case, the print has a wide base, so it is not nearly as susceptible to knocking over as the prime tower.  Another benefit would be that build space would not be taken up by the prime tower.

  • Link to post
    Share on other sites

    Posted · Feature Request: multi-extruder, single nozzle, without prime tower

    In my experience, using a UM printer with UM-brand filament, prime tower have become useless. I guess it should be possible to find settings with any combination of printer and filament to make the prime tower useless as well, thus saving a lot of time and material.

  • 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
        • 4 replies
    • Create New...