Having a hard time solving ringing/ghosting?



  • I think that is what is going on here. I have changed Jerk and acceleration settings it helped a bit. But I also have this issue with the corner of the cube. Thoughts on what to do to solve this?

    0_1554600992167_Configreprap.txt

    Cube on left is the first print.
    0_1554601003334_Duet.jpg
    0_1554601012310_duet2.jpg



  • Your jerk values in your config seem a little off
    In your config you have M566 X30.00 Y30.00 Z0.40 E5.00
    But the jerk values are taken in mm/min here, so your values are very low, almost as if you were entering them as mm/s.

    Your acceleration values are still quite high, and that can still lead to ghosting/ringing.

    I would suggest trying

    M566 X600 Y600 Z30 E2000 ; jerk in mm/min
    M201 X6000 Y6000 Z100 E5000 ; max accelleration
    M204 P600 T4000 ; print and travel acceleration
    

    The criss cross pattern you see on the surface is from the infill showing through. Pretty common if you're using Cura. You can reduce the infill overlap percentage, and change it to print infill after walls. That will help a lot with that.



  • @phaedrux

    I copied values directly from marlin. It is moving really slow around corners. almost jerking around a corner. I know its not right the corners of my brim lifts and looks terrible.

    As far as cura is concerned now that I am using RepRap should I use a different slicer?



  • @jtroutt19 the values in Marlin use mm/s reprap uses mm/min. So that explains the super slow cornering with your values.

    Cura is fine. Just make sure to switch to reprap gcode flavor in the printer settings.



  • ... and use relative E values.



  • @mrehorstdmd

    So you are saying to edit the Start gcode and insert M83? Could I just edit my Config and put the M83 in there so it is always relative?



  • @phaedrux

    That makes alot of sense then. I was wondering why the values were so different. I did change the flavor over to Reprap.

    As far as doing custom gcode stuff. If the start gcode is blank in cura with is just use default firmware settings? Prolly a topic I can answer by searching. I am currently waiting on a new cube to get done printing.

    I found that my Bed was not tight as well Prolly a reason for some of the ringing and ghosting?



  • @jtroutt19 said in Having a hard time solving ringing/ghosting?:

    @mrehorstdmd

    So you are saying to edit the Start gcode and insert M83? Could I just edit my Config and put the M83 in there so it is always relative?

    You can have M83 in config.g, but Cura also has a check box for relative extrusion, and it will insert it before the start gcode block.

    In the start gcode block you should probably at least have G28 to ensure the printer is homed. Once you're more familiar with the Duet and gcode in general you can get a little more fancy.



  • @phaedrux

    Its a whole lot better. So I am still having an issue with the back right corner, if view from the front of my printer, of the cube. it looks bunched up.

    So watching the print head it just very momentarily pauses during making the brim each time the nozzle passes the front left corner.

    The front left corner of the brim is raised up as well.
    0_1554613960111_duet1.jpg
    0_1554613968022_duet2 .jpg



  • there are some ways to try and combat that. filament is oozing out of the hotend at those small pauses.
    Cura has a feature called coasting to try and combat that.

    However Duet implements an even more advanced feature called pressure advance
    there is a whole thread about configuring that.
    https://forum.duet3d.com/topic/6698/pressure-advance-calibration/3



  • @veti Thank you for that I will look into that.

    I will say this I was thinking about why it was pausing on that corner and realized at that corner is where it advanced to the next layer. I had retractions enabled. I thought maybe that is what was causing it so I turned retractions off. It has for sure improved.

    That said it is still having issues on the corners where the the letters are not in.

    0_1554617900767_duet1.jpg
    0_1554617912624_duet2 .jpg



  • Running without retractions isn't really a great idea once you start printing something more complex than a cube. You'll end up with a lot of stringing and under runs at the start of a line after a travel because the filament will ooze out.

    In addition to pressure advance you should increase your Z axis speeds and acceleration a bit to make the pause at layer change quicker. Same for the extruder speed.

    Right now you have M203 Z250 E750 and M201 Z100 try increasing these to M203 Z600 E6000 and M201 Z300. If it behaves badly, back it off a tad.

    Also, how fast are you retracting in the slicer? Your config was limited it to 12.5mm/s which is very slow. 35-50mm/s would be more reasonable.



  • @phaedrux

    You knowni didnt even think about that. Thats fantastic. Hate being a noob. Anyway im done for the evening now its almost 3am here. I make suggested changes and report back tomorrow.

    I agree with wanting retractions to be turned on. But i was on the right track at least i was trying to speed up that layer change. I gotta get used to knowing that i can go in and say go faster.

    Thank you again!


  • administrators

    You should also look at pressure advance (M572) and dynamic acceleration control (M593). But start with retraction.



  • @phaedrux

    I did the pressure advance test code print.

    0_1554658404046_pressuradv.JPG

    I made the suggested changes as well. Didnt behave badly at all. I was thinking I would bump them up a bit more. Retract speed is at 50mm/s.

    Im not sure what I should set my PA to though. not sure how to interpret that print.



  • What kind if printer is it? What kind if extruder? Is it using a bowden tube? If so, how long?

    A good value to start with on a direct drive extruder is 0.05.



  • @phaedrux

    Its an ender 3. Bowden extruder and the tube is right at 250mm long. I set it at .1

    I've discovered why my corners look better on the layers that include letters. The layer change when the printer moves the nozzle up happens in a different spot.



  • 0.1 sounds about right for that setup. Some pressure advance is better than no pressure advance.



  • @phaedrux

    So i discovered something else. The babystep buttons for the z axis if i put a .2mm offset the corners look alot better but the bottom layer on the buildplate looks like total crap.

    Makes me think it may be an issue withnover extrusion. But ive double check my value there and its pushing out exactly a 100mm



  • If you've already leveled the bed as best as you can, and you have a z probe, you may want to consider mesh grid compensation to help with the first layer.

    https://duet3d.dozuki.com/Wiki/Using_mesh_bed_compensation


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