Pattern Pressure Advance Calibration
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I think the print it so small that it doesn't really have much opportunity to curl and cause problematic nozzle strikes
No overhangs either -
a) firmware retract is the only way you get proper retract on mixing hotends (2-in-1 like the relatively new tai chi, 3/5-in-1 like the venerable diamond, or 6-in-1 like @deckingmans). Maybe that's not relevant for your PA test.
b) I tend to stick with firmware retract because it's simple to adjust during a print if necessary.different unretract length is not often needed, but it helped me with weird filaments and with large diameter nozzles.
I'd agree that both are ... rare use cases that don't necessarily need to be reflected. But I personally could use them.
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@oliof I'll consider putting them under expert mode
For some background, I went into the 3d printing discord and showed it to some new folks, and they were really confused and overwhelmed, basically. Got a lot of screenshots with "what should I change"?, haha.
That's part of what lead to me trimming the fat like this
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@Ellis I absolutely understand and commend the goal of making this accessible to newcomers. I also do not expect any issue I file to be followed up with (-:
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@oliof
I am curious if the lack of an unretract distance setting causes issue with the test in your case.If so, that seems a valid reason to add it - so let me know how it goes
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@Ellis I've been setting it to 4mm. Should I print taller to look for any particular Z artifacts?
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@mrehorstdmd I think only 3-4 layers are needed, just to ensure that it's decoupled from first layer squish, but you can also print it tall to look at the sides of the walls too!
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New version is printing much better, thanks!
I do wish we could get line width % back though.
You might also consider printing the PA labels at the first layer speed and/or with a thicker line width for readability.
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@CCS86 It's still there! Tick "expert mode" up top
I will reduce glyph speed to first layer speed and see how they print for me -
@Ellis said in Pattern Pressure Advance Calibration:
@CCS86 It's still there! Tick "expert mode" up top
I will reduce glyph speed to first layer speed and see how they print for meAhh, missed that! Didn't notice it added settings to the other categories. Thanks.
Interestingly, testing at 70mm/s I see the sweet spot around 0.037
But at 120mm/s, the best value actually drops to around 0.028
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@CCS86 PA seems to change at different speeds, same story with Klipper - unfortunately nothing can ever be simple, hah.
That's why I usually recommend to tune at your perim speeds, as that's where you will see it most
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Ok, added firmware retracts and slowed the numbering down to first layer speed. They are looking cleaner for me now without having to bump flow
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@Ellis
Ran it a couple times after those changes and it works sweet👌EDIT:
Based on the results it looks like 0.08-0.09 is where i should be, isn't that on the higher side for a direct drive setup(Voron Stealthburner loaded with a Revo Micro and a LGX Lite) ?🤔 -
@Exerqtor that does seem very high. With my LGX lite and Revo on a v0.1 I'm looking around 0.05
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@Exerqtor PETG by chance? If so I've found it to need around double that of ABS/PLA. Abnormally high also can point to a sneaky partial clogs, even though it's still printing
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@Ellis
ABS Pluss (Fiberlogy) actually
@255c i haven't done a coldpull in a while so i could try that and run a new test ofc. -
@jay_s_uk I made a few runs, tweaking some of the printing parameters and settled at 50mm/sec, 1.2 mm line width, accel 1000, PETG, 130C nozzle, 70C bed, 0.5 layer thickness, retraction, and z hop.
I shot some pictures of the result with PA stepped from 0.05 to 0.15 by 0.005 steps.
I don't really see much in the way of blobbing at the corners at the low value settings, but there are definite gaps that get bigger as PA increases.
After the first two steps, I don't see much change at the ends of the lines throughout the rest of the range. -
@mrehorstdmd The blobbing gets worse at higher speeds or lower accels, 50mm/s may just be a bit harder to read - though I imagine flow rate is a limitation here
This was with a 1mm nozzle? I'm also curious if the numbering printed okay, if you had that enabled. The preview freaks out a bit at such line widths since it renders the extrusions as cylinders instead of flattened ones.
My best real world results have been to pick the higher value a little before gapping, inversely to the usual recommendation of erring lower.
Looking at your results, it's certainly subtle. I'd hazard to guess around 0.055-0.06.
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@Ellis Yes, 1mm nozzle. I didn't print the numbering- previous attempts resulted in illegible blobs- now that PA is "tuned" I need to check retraction- that may be why the text came out so poorly. I have struggled to get retraction tuned well with the 1 mm nozzle- you tune it up using test "posts" and get it working, but then you run a print and it doesn't look right, and after messing around, realize that the tuning worked because of the spacing of the test posts, and when the spacing changes, retraction gets ugly again.
A few years back someone wrote an add-on for Cura (IRIC) that varied retraction based on travel distance. I never got it working well, but maybe it needed PA, too. I'll be tweaking retraction later today.
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@mrehorstdmd Currently the numbers are a static size, so the illegible blobs doesn't surprise me. I would need to figure out how to make them scale, I think.
Maybe I will disable numbering for >0.8mm nozzles for now.
Was hoping it would surprise me, but I'm not surprised
The retraction is an interesting idea. You could theoretically do that in a macro - in Klipper, at least, but I believe RRF3 macros aren't too far removed
