Hello! So I am a newbie at this 3d printing stuff but I am having issues with my Elegoo Rapid PETG prints, mainly with the first layer.
I have tuned my flow calibration to 0.966 (up from the original 0.95). Although it could go a bit higher according to the flow calibration, I was getting overextrusion on large flat objects causing the top layers to buckle weirdly.
I have tuned my k-value to 0.042 (Manual calibration showed between 0.040 and 0.045, automatical gave me 0.042, so went with that).
Classic wall generator. I have a very slow first layer (50mm/s first layer with 105mm/s first layer infill) along with slowed down outer and inner walls. I have one wall on first layer, rolling with 3 walls using inner/outer/inner. Monotonic surface pattern on top and bottom, standard 0.20 profile wall widths except for the top surface is set at 0.25 because I tend to like the way that looks. Speaking of the top surface, it looks much better except for small pin holes & possible some overextrusion…?
Should I crank up the initial layer flow a bit maybe? Or is this some kind of PA k-value issue?
Thanks for your time!
Calibrating means just that but not to play with values 
And your k-factor seems quite high, even for PETG.
But if the flow ratio is off the k-factor can’t be properly established anyway.
Take your time, use a magnifying glass and good light.
The flow ratio patches should be judged by the best overall look.
No gaps between the infill lines, nor build up where the join either, a nice, flat surface.
After that do the k-factor and don’t by shy to check both pattern and line calibration options.
Did I mention to take your time?
This goes for the first layer as well.
Better to go slow then to rush things with PETG.
Well… I tried. Did a flow calibration on the PETG again. Ran the Orca YOLO test based on my current flow of 0.966 (so 0 would be that flow rate, 01 would be 0.976, 02 would be 0.986, -02 would be 0.946, etc.)
I went with 03 as that one felt the smoothest - 02 still had very minor gapping in the center which light leaks through, 03 and 04 both looked good. So I set my flow ratio to 0.996 for the PETG filament.
Next I did the PA calibration:
I choose a k-value of 0.029. 0.030 still seemed to have slight gaps on the corner that aren’t visible in the picture, but maybe I should’ve went with 0.028?
Either way, I can’t say I noticed much of an improvement. Slightly better gaps on the first layer between infill and walls, but I also see more gaps in the infill now for some reason
Top surface looks better I think:
Anything that I messed up with the calibration that you can see? In PLA, this shape prints with none of these issues with largely the same settings (of course different flow rates, PA values, etc, but the actual slicer settings are pretty similar - classic walls, one layer on top/bottom, etc)
I did use a 0.20 elephant foot compensation on both of these prints, but I’ve been using that with PETG with no other issues like this. Although I haven’t really printed that much in PETG yet
It is odd that you have visible gaps on the first layer.
Sure you have the textured PEI plate selected and not a smooth one?
0.2 for the compensation? I have around 0.05…
A bit further down in those advanced settings you can adjust the flow ratio for the first layer.
Maybe setting that to 1.0 or above helps but should not be required.
Yep, definitely have the textured PEI plate selected in Orca
This stuff can be so frustrating sometimes…
Just wanted to reply to let everyone know that this was figured out.
That elephant foot compensation seemed to be the culprit. I just turned it off for this print since it has chamfered edges there anyways. A reply on my Reddit post pointed this out along with this article explaining, but you were right on:
Perimeter Separation | Ellis’ Print Tuning Guide
I’m still seeing very slight gaps in the infill on the first layer, but I can probably just play with the flow ratio or the initial layer flow ratio slightly to fix that.
Thank you kindly for your suggestions for calibrating properly & that I should stop trying to outsmart the calibration
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You worked it out and learned something along the way, I call that a success 
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Remove the K factors on the filament settings and do it in Bambu Studio using the auto calibration instead as this will store the settings in the device,
Flow Calibration is the same as PA calibration so if you establish both it will cause issues during your prints,
