Not sure why this is happening, but it looks burnt and ragedy? what gives here?
How many top shell layers are being used?
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The flow is not correct.
Try to calibrate it using a solid infill test cube with a few sparse infill layers and at least 5 top layers.
The flow ration is good once the top layer comes out smooth and without saw teeth on the wall loops.
Once that works do it again but print the cube solid with 100% rectilinear infill.
Watch the layers…
Build up forming means you have to reduce the flow rate a tiny bit more.
Tiny gaps forming between the infill layers mean you have to go up a tiny bit.
This test works best using low layers heights, e.g. 0.1 or 0.08.
The patterns you see are a combination of vibrations and over-extrusion.
The bridging layer after the sparse infill might not be perfect, resulting in the first solid layer to be rather uneven.
Every time the nozzle hops over these humps and bumps it transfers this to the new layer.
Like a dirt road with a lot of traffic you end up with more and more corrugations…
You can compensate for these defects to some degree by increasing the nozzle temp.
But that is a bad idea if the cause is the flow rate…
Means while you might be able to get smoother layers after a sparse infill you will reach the point where the excess on the yop layer has to go somewhere.
And that only too often means getting a smooth looking surface with lots of teeth around it…
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thank you for the detailed reply, but its going to take me a bit to read through that. Very detailed and thank you. for the most part, im using the default settings in the bambu slicer.
anyway to export my current settings and show them to you?
Top shell layers are 5. That is the default setting in the slicer. i did not change that.
It is not about the amount of layers, it is about the flow ratio…
This looks very similar to a first layer test where the flow ratio is turned too high. To rule that out, change the flow ratio to something lower, like from the typical default of 0.98 to 0.85, and run the test again.
If the print changes significantly, then I would pursue a flow ratio calibration. Even after you’ve done that, you may want to manually run your print and dial back on the flow ratio for this individual model, repeating the test until it comes out to your liking. Then save that filament profile under a name you will remember, describing the special circumstances of that filament profile.
One note though. You may want to create a cube primitive of 100x100x0.2 for this test. This will save a lot of time and filament and will allow you to run multiple tests.
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I know this reply is coming months later, but your advice was spot on. I reduced the flow ratio from the default .98 to .85, per your recommendation and my prints, the ones I have created and sliced, came out perfect! Thank you.
This community is great and I really appreciate your insight!
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Thanks for closing the loop. By confirming this worked, you’re adding valuable knowledge to the community for others facing similar challenges.
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