I’m printing PETG on my P2S with AMS. I have two of them. I’ve used both printers with PETG and PLA and cannot get my flush text to come out right. And the weird thing is… on one occasion it actually came out great (the 0.12 one). I’ve made a sale if I can get them done in the next day or so. All of them were printed with 1.2 layer height and everything else default. I’ve tried some ChatGPT advise which had me going down rabbit holes for hours with setting changes that did nothing. I’ve tried different colors to no avail. See all the little holes around the letters? Any help will be appreciated.
Looks like your Flow Dynamics calibration is off. Did you dry and calibrate the Filament?
Once done, further thoughts concern the bottom surface pattern where you could have a look at a concentric pattern and of course, fine detail (such as text) and its surrounding perimeter are usually much better on a bottom surface when using the Arachne wall generator.
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I did dry the filament. Flow cal sounds promising. I’ll try that right now and let you know. Will be a while of course.
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The top layer infill pulled back from the walls is usually a calibration issue.
Thanks, checking that now.
Run a real calibration from Studio. Manual is much better.
Takes some time, but gives you the best result.
You get 9 samples, then you choose the one that looks the best. (You can go even farther as well)
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Flow rate is not it what you want to adjust, flow dynamics is what controls the point the extruder stops extruding during a linear move. Also know as pressure advance.
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IMO this is a Pressure Advance issue, not a flow issue. The printhead has to slow down to change direction. So extrusion has to be slowed down, too. But when the direction has changed and the printhead is accelerating again, the extrusion flow rate isn’t speeding up quickly enough and you end up with a small gap until the extruder catches up.
The calibration you want to do is the Pressure Advance calibration.
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Well, that sounds promising. I don’t know how to do it, but I’ll start looking. Thank you.
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The machine does its own PA calibration if you tell it to run the flow calibrations at the start of the print. But the automatic calibrations can have some variability. Might be good one time and not so good the next time. Which is why Studio also has a “Calibration” tab where you can manually do these same calibrations. If you calibrate by hand and don’t let the printer run its calibration each time, you will get more consistent results (provided you maintain the same level of filament dryness between prints).
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You can also set your bottom layers to monotonic, instead of monotonic line. I think it will help.
I’m not sure about this one but it’s possible turning on embed walls into infill may help. It’s another thing to try if nothing else is working.
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Hi @BillByrd ,
Did you do the Flow or the Flow Dynamics calibration?
If you have completed the Flow Dynamics calibration but holes still appear, have a look at the comment from @Alex25 .
Finally, a concentric bottom layer pattern will not address the root cause, but it has far fewer sharp corners.
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PS: Bambu states ±10% for auto-calibration but in my case (X1 & H2) it is much better than that. And much better than what I can achieve manually.
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IMO I agree, the printed bottom shows flow dynamics / pressure advance problem. The automatic calibrations are sometimes not good enough, run the test yourself and plug in the value to the saved filament.
Everyone seems to agree on the manual cal. Maybe I’m doing it wrong, but when I ran it, the printer printed a bunch of lines and ask me to judge when one was best. And apparently the best translates to a number which is the k factor. My 80 year old eyes couldn’t tell the difference, so I sent it up to Chat GPT which gave me its opinion. At any rate, my problem is only worse. I’m dead in the water because good text is an important part of the product. I’ll keep trying, and thanks for all the responses.
Before you try too many things – Did you turn off the prime tower? If you did, turn it back on and print one to see the result.
No, I never got around to it and decided it was there for a reason. I just drove 60 miles in the dark to get some PETG from a friend on the unlikely case it was my Sunlu PETG. Before I got to his house, I knew it was a waste of time because I get the same result with PLA. Several of you suggested pressure advance, so that’s what I’m looking into at the moment. If anyone knows how to tell me exactly how to do that, it would be great. I did a manual cal last night and it laid down some lines for me, but I could tell the difference. It wanted a K factor. I’m not sure, but I think I plugged in 1.0 or whatever ChatGPG thought looked the best. Back at it. Gonna be an all nighter again for sure.
the k factor is usually between 0.010 → 0.060 , the leading .0 is important for scale, its a small number. if you put a huge number like 1.0 it would explain flow problems. That number is measuring seconds
You could send a pic of the test here, and we could try to highlight our opinions.
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That’d be wrong. That number might be OK for “Flow” but not for “Pressure Advance”.
That ^^^^
