Lines not completed before printhead moves

[OnCor 0]

Hi all. I've got a strange issue with Cura on my Creality K1. As some lines are printed the printhead moves before they are complete. I've attached a photo that shows a sizeable gap in the skirt line and some smaller gaps in the circles and wall of a print. The project has also been attached with the setting details. I do not have coasting or wiping enabled. I'm not sure why the printer isn't able to finish the lines. This also leaves a pretty prominent Z seam on the prints as well. Thanks in advance for any feedback/insight on this issue!

TFT Bottom.3mf

[Cuq 198]

Newbie into 3D printing? Is this your first printer?

Edited December 13, 2023 by Cuq

[OnCor 0]

LOL! It's not actually. I have a CR10S Pro V2 that I've been printing with for a couple of years. I don't have this issue there and aside from machine specific settings everything is mostly the same between the two machines. I'm sure it could be something obvious, but I just can't seem to figure out why the K1 stops extruding so soon before moving on and leaving these gaps in the lines. What's even more strange is the fact that it does this most prominently on the skirt. The file I'm trying to print is the same one I've attached a photo of that came off my old printer. It's a two piece enclosure for a small display. I have this same issue regardless of the file I try to print though.

[GregValiant 1,261]

The glare in the image makes it hard to see, but the skirt doesn't really look squished to the bed.  If the leveling is off then you can get that.  The filament doesn't stay down and you can get a short "curl up" that sticks to the outside of the nozzle.

Maybe you need to touch up the Z offset.  As a test you could try turning up the "Initial Layer Flow" to maybe 110% and see if it makes a difference.

[OnCor 0]

I turned up the flow to 110% and re-ran the print on a black build plate for better contrast. The gaps are still there unfortunately. The problem is that my squish is dialed in fairly well and as I let the print run there were waves in the bottom layer from over-extrusion. So this is not really a viable option.

 

I tried increasing the retraction prime amount thinking that perhaps the issue wasn't the closing of the line, but a lack of plastic in the nozzle when the line is being drawn initially due to retraction during the move. It does seem rather "skinny" at the starting point, especially on the skirt line. Again this change helped to close the gap some on the first layer, but caused issues elsewhere in the print. I'm not sure if there is anything else worth trying on this to fix the issue. Thoughts?

 

[PartySausage 13]

Do you have coasting enabled ? If so you could try disabling it & see if there's any change 

[OnCor 0]

19 minutes ago, PartySausage said:

Do you have coasting enabled ? If so you could try disabling it & see if there's any change 

 

I don't have coasting or wiping enabled as I know those could cause issues with plastic running out before the end of a line is completed. Plus I've heard the K1 printers don't deal with coasting properly anyway so I've had that disabled all along.

[GregValiant 1,261]

I'm not sure where to go with this.

What is happening with the skirt might be a function of your startup gcode and the first couple of lines that Cura puts in after the startup.

My startup has a 2mm retraction after the purge lines.  Then Cura adds:

G92 E0

G92 E0

G1 F2100 E-6.5

If I leave that in place then the skirt doesn't start on time because the filament is 8.5mm behind the nozzle and the first prime is 6.5mm.  For a fix I use Search and Replace to change "G1 F2100 E-6.5" to "G92 E-3".  That allows the skirt to start when it should.

 

The problem at the round holes is different.

 

Cura does the entire retraction in a single line of gcode.  That doesn't happen until the nozzle has reached the end of the extrusion.  In theory, what you are getting there can't happen because the extruder is turning right up to the end of the move.

 

The project file shows that you have "Wall Order" set to "Outside to Inside" and "Retract before outer wall" is enabled.

As an experiment I would suggest changing the order to "Inside to Outside" (to move the problem to a non-visible location), and then turn off "Retract before outer wall" (which admittedly has never worked well for me and so I simply don't like it).

 

 

[OnCor 0]

I tried your suggestions @GregValiant. Unfortunately the small gaps in the circles persist. On my old Bowden style printer I would get some drip from the nozzle if I didn't retract before the outer wall. Doesn't seem to be an issue on this new Direct Drive machine though. I suppose I can probably leave that off going forward.