I cant get my Anycubic Kobra 2 with Klipper to print correct. The first mm of each layer are faulty, resulting in a bad tooth in gears.
I tried to slow down the print, tried to minimize/deactivate retraction, fiddled with z offset and first layer height, lowered bed temp, altered the extrusion rate. Nothing works. Everything else seems fine, slim z seam, nice walls, no over/underextrusion.
Anyone got a hint how i could fix that?
Edit: I cancelled that Print, the Problem is only in the first tooth:
the tooth in the marking should look like the ones above it.
Try adding a skirt to your print in your slicer. That should ensure that your nozzle is good and primed by the time your printer actually starts printing the first layer of your part.
I don't know in what order that layer was printed, but it looks to me that no material was leaving the nozzle throughout the 7:00 to 3:00 or so portion of it.
In the second photo of the fully printed part it's hard to see the issue.
Looking at that first layer, the first tooth looks very similar to the internal perimeters of the teeth that have had two perimeters printed.
Is it possible the first pass on the first tooth is printing an interior perimeter whereas the first path on the other teeth is printing a different perimeter? What does the first layer look like when you let it finish the layer?
And could you please provide a picture of the first layer as rendered in the slicer?
I can see that your printer is doing some nozzle priming lines on the side of the bed before it starts the actual print.
Does it retract after finishing the priming lines? It may be retracting too far/not recovering far enough before it starts the print moves, and depending on the slicer and printer firmware specifics, that function might not be controlled by normal retraction settings.
I changed every retraction setting ive found. 2x in PrusaSlicer, 1x on Klipper, nothing changes. But with Cura Slicer the problem is gone. So i obviously f*ed up some setting in PrusaSlicer. Will test more today.
That is interesting. Does CuraSlicer do the same priming lines? Have you tried the print with PrusaSlicer without the priming lines?
If you can figure out what Cura is doing differently in that section of the gcode you could put those lines in the custom gcode box in PrusaSlicer and get the same results.
My guess is that is a slicer error because it couldn’t make the shape with a combination of the tooth size on the gear and wall thickness settings. Does it look right in the slicer after it is sliced on the first layer?
It looks correct in the slicer. I changed the slicer btw and with cura everything works fine. So its something in PrusaSlicer. Will test some more today.
Looks like that's a bed leveling problem. You can change the z height all you want but if the bed isn't level to your Z axis, one side will always be too shallow and one side tooDutch? If it gets too close the nozzle it'll put out almost no plastic which I think is what youre seeing.
This was my first guess.
I'd also recommend an initial 1-2 loop skirt if it does this on the skirt it's the level. If it still does it on the gear it's the stl file.
Oh I couldn't even see that tooth at first. I just saw the varying layer width.
That's definitely going to be a slicer or model error. Make sure your input STL doesn't have any missing faces or geometry and that the teeth were generated correctly