Help with first layer
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Hi,
i am having the proble you can see in photos, and i dont know can cause it
Its not Duet related issue, but post here if you can help me
If you see the images of first layers, its jagged
Any ideas? Its Asa at 240º bed 90
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@peirof, looks like a tad of over-extrusion to me ....
To explain my thinking the first layer here is built from the outside in. Let's say you have a very slight over extrusion and the material is laid down a bit wider because of that. The next circle printed will cover the over extrusion and so it actually would need a bit less material. Since it puts down the same amount of material (slightly too much) plus the overage from the first circle and you get even more over extrusion. When you repeat that many times over then you will see quite a bit of over extrusion on the last circle printed.
Not that all over extrusion will always be forced out on the side of the nozzle that doesn't have anything restraining the material from squishing out - in this case the excess can't be squished out to the outside so it ends up on the inside instead.
Either reduce first layer extrusion a bit or increase the distance between nozzle and build surface by adjusting z=0 calibration. -
@jens55 I think you are right, I have lowered the extrusion multiplier to 96% in the DWC, and it seems that this effect has diminished. I cannot draw a clear conclusion because there was little left of the first layer.
But another fact that I had forgotten to comment on, and that supports that theory, is that in the first lines, it is a circle, that effect is not appreciated, perhaps from what you say, it does not bother the over-extruded material on the sides
What is curious is that in the following layers that effect is not appreciated ... Almost certainly, from what you say, they are not very thick walls, and they can be expanded on the sides.
I will comment on the results of the tests, but it seems that YES that is it.
Thanks @jens55
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@peirof, I don't really understand what you are saying but this effect is only ever present on the first layer because subsequent layers are the appropriate height. Let's say you are trying to print 0.2 mm layers. Layer 2 and up always have the 0.2 mm distance from the previous layer The first layer height is totally dependant on your z=0 calibration and in the majority of cases (at least with me) it is never 100% correct. If the nozzle to bed distance is 0.21 mm everything is fine but if it is 0.19 mm then you are over extruding. I tend to set up for slight under extrusion on the first layer to avoid this issue.
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@jens55 Better, or at least in the beginning, with your advice.
We'll see...