Kind of little stairs on z axis, any idea ?

[DzzD]

On the A20m I got non planar wall, look like mini stairs (see pictures), specialy on cube border along z axis, this is a very small default but I have not this problem with my other printer.

Those mini stairs are constant along z axis on the whole height.

Any idea ?

[Jarda3d]

the right side of X axis is too tight. And left side at Z screw possibly not tighten well.

Top side seems over extruded

[DzzD]

thanks, so I should try to lose a little right X axis wheels ? I start a new print with this modification to see if it help.

The top layer is fine, probably the photo give this impression of over extrusion but it's really nice in reality.

[DzzD]

I tight the left x axis wheel and lose the right one but unfortunatly no change , result is the same, little stairs are still there, do you think I should try to tight it even more ? NB: they appear in all the fourth borders along z axis.

I noticed that the default A20m profile on Simplify3D set the jerk to 10, I will try with 9 and see if it help.

[DzzD]

same result with a jerk set to 9 ...

[Jarda3d]

both GT2 and bed wheels are tight?

[DzzD]

Yes they seems to be ok, but I will tigh them a bit more and check if that help.

Also I am wondering if it is not related to retractation because stair seems to be 4 layer height and retractation occur on each corner every 4 layers (according to simplify 3d preview), first layer it retract on border 1, 2nd layer it retract on border 2 etc...

Also in vase mode the stairs completly disapear.

[DzzD]

Some more tests results :
- Trying with the second extruder (a20m) and a different filament doesn't help, same issue.
- Disabling retractation doesn't help

It is maybe something related to slicing (Simplify3D) because I notice that the nozzle go twice at the same location exacly every 4 layers, and stair's are every 4 layers.

I mean there is maybe something wrong on the slicing, because it go on the outer perimeter, draw it, than get back at the same location it started rather than a bit before, so the nozzle print twice at the location it started the outer perimeter.

[William]

Hi, you can check if your institution is loose,
If it is, tighten it.
Try to re-slice the model.

[DzzD]

could be related to the lack of newer features like junction deviation & linear advance being available to use.

Yes maybe, I read a lot about linear advance and my conclusion is that it has also probably a downside, because if not I suppose that all manufacturer will enable it with a default value that works in most case , but maybe they already do that ?

I dont read and dont know a lot on junction deviation but I see that it has something to do with corners, but on this cube corners are nearly perfect with no infill even with multiple outline, I am not sure it will help in this special case.

I really think that this problem may come from the path of the nozzle when using infill. I will investigate more on the generated gcode to see if I am right or wrong. Maybe I missed an option in the slicer but I have done so many tests.

For now here are some results :
Those tests have been performed on two printers a20m, cr10s pro, three differents extruders, three différents filaments, two nozzles 0.4 and 0.6, one slicer Simplify3d.
Layers height : 0.3
Vase mode => render is ok
Two outline + infill 15% overlap infill 15% => render stairs on corner
Two outline + infill 15% overlap infill 0% => render stairs on corner
Two outline + infill 3% overlap infill 15% => render stairs on corner
Two outline + infill 1% overlap infill 15% => RENDER IS ok ! ( I really cant explain this result )
One outline no infill => render is ok
Two outline no infill => render is ok
N outline no infill => render is ok

NB: with layer of 0.1mm all print are ok, with or without infill, at least my vision is not enought accurate to see them...

It is a very small defect, less than half a millimeter, that appear with layers of 0.3mm height, nearly invisible with lower layers height.

StairsMacro.jpg (197.47 KiB) Viewed 19901 times