Jump to content

Lift head setting


Falconator

Recommended Posts

Posted · Lift head setting

Hi, been 3D printing for a while and have moved to Cura as my go to slicer, to make my prints better on small layers I have turned on the Lift Head function in order to allow the PLA that I print with to solidify before the next layer, however this then results in ooze from the print head which can lead to under extrusion in subsequent layers. There is the option for retract when Z-hopping but not for lifting the head or are these two things the same, if I enable retract for Z-hop will it view the head lift as a Z-hop and retract the filament?

If this is not the case could this be considered as an option for future versions of Cura, either combining the setting of retract for Z-hop which will also cause a retract on head lift or a bespoke setting for retract on head lift?

  • Link to post
    Share on other sites

    Posted · Lift head setting

    I'm pretty sure it *does* retract when it does "lift head".  But retraction only lasts for a second or so - enough time to jump to a new part of the print.  But lift head will often sit in the air for 3 seconds - plenty of time for a micro sausage to come out and then get deposited on the print when it starts printing again.

     

    The only good solution I've seen is to print a tower next to the part so that the print head can go to the tower and print a little bit to give the print time to cool (just a few seconds is usually enough.  Keep the tower in a position such that when the head goes to it the fans blow on your part (if possible).

     

    Instead of a tower, sometimes I print 2 or 3 or even 7 of the same part.  While printing one parts the other parts all have time to cool.

  • Link to post
    Share on other sites

    • 11 months later...
    Posted (edited) · Lift head setting
    On 2/28/2021 at 5:55 PM, gr5 said:

    The only good solution I've seen is to print a tower next to the part so that the print head can go to the tower and print a little bit to give the print time to cool (just a few seconds is usually enough.  Keep the tower in a position such that when the head goes to it the fans blow on your part (if possible).

     

    Instead of a tower, sometimes I print 2 or 3 or even 7 of the same part.  While printing one parts the other parts all have time to cool.

     

    this is the smartest dumb idea i've seen yet for dealing with this. on my small parts lift head has been extremely necessary so far. probably going to do the tower idea. make a little square extrude straight up next to my main model. i was spending lots of time trying to include bedwipes here and there but that requires it to go all the way back down then up again. this is way better.

    Edited by darkconsole
  • Link to post
    Share on other sites

    • 1 year later...
    Posted · Lift head setting

    Hi everyone! I've doing that (multiplying the same part to make the layer last longer) but sometimes it is not possible. The real problem is not the stringing or oozing, but the position where it happens. "Lift head" only moves up the head 3mm, on the same X and Y position, so the oozing falls on top of the part. /facepalm/. Is there a way to specify a relative position to move?

  • Link to post
    Share on other sites

    Posted · Lift head setting

    There is no "Park Head" option for Lift Head.  It could be done in post process but exactly how it's done raises some questions.

    • You mentioned a "relative" park distance but would 5mm be enough?  The nozzle may well still be over the part, just not quite where it was.  An absolute park position might send the head from the right rear to the left front.  That might take longer than the pause.
    • There could be some drool hanging from the nozzle.  Should it drop back down in the Z and wipe on the side of the part, or go back over the part and stick it where the Z drops back down?  That would seem to be right back where you started.
    • Should the time spent in travel be subtracted from the pause time?  A bit more time wouldn't hurt.

     

     

  • Link to post
    Share on other sites

    Posted · Lift head setting

    Attached below is a collection of 5 post processors.  The last one (todays work of art) is Lift Head Parking.  Unzip and put the "LittleUtilities.py" file in your configuration folder, the "scripts" folder.  On my Windows computer it's "C:\Users\...name...\AppData\Roaming\cura\5.4\scripts.

    It figures out the shortest orthogonal move to get off the part and goes there, waits for the G4 pause, and then goes back, drops down, and the print continues.  There will likely be a booger.

    In regards to Cura's Lift Head retractions:  If there is a normal retraction just prior to the Lift Head movement, then Lift Head does not include it's own retraction.  If there is no retraction in front, then Lift Head will include a retraction.  In this snippet a retraction was called for because there was none ahead of the move.

    G0 F9000 X199.375 Y36.033

    ;Small layer, adding delay
    G1 F2100 E3451.70922
    G1 F600 Z13.4
    G0 F9000 X206.461
    G4 P8132
    G0 F9000 X199.375 Y36.033

    The two bold G0 lines were added by the post processor LittleUtilities / Lift Head Parking.  Rather than moving all the way to a corner it just moves straight to a point over the skirt/brim/raft.

     

    LittleUtilities.zip

  • Link to post
    Share on other sites

    Posted · Lift head setting

    Amazing. Thanks a lot man. Im printing with PC and it was giving me a headache. I mainly print gears and mechanical stuff for industry, and most of them are quite small (PC, PCABS, PA). So i end up with a lot of parts just for the sake of having one well printed. Im gonna try it right now. Thanks again.

  • Link to post
    Share on other sites

    Posted (edited) · Lift head setting

    You're the test case so let me know what you think about it. 

    Edited by GregValiant
  • Link to post
    Share on other sites

    Posted · Lift head setting
    On 7/12/2023 at 7:01 PM, GregValiant said:

    Your the test case so let me know what you think about it. 

    It goes quite well. The printhead moves only on Y axis, all the way to the edge of the brim, wherever it may be. What i havent tried, is to put two objects, on different positions on Y axis, to see if the printhead moves to the absolute further position over the edge of the brim on Y axis, or if it is relative to the current X position and just goes to the actual edge of the brim (i dont know if that makes sense)

  • Link to post
    Share on other sites

    Posted · Lift head setting

    I used the MAXX, MAXY, MINX and MINY that Cura puts into the front end of a gcode.  The nozzle will go to either the Y or X skirt/brim based on which it is closer to.

    With two models, a skirt would go around both.  So the math in the script might go the long way across a model because the skirt/brim might be closer that way than traveling all the way to the other side.

  • 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...