the “front outer” layer as viewed and printed doesn’t seem to be sticking to the other layers…I sliced it with a knife as per attached pic and it just fell away, same on the "front / inside of the rear wall
All others seem to stick OK
Looks to me like you’re under extruding. Partial clog, issue with Extruder stepper motor or drive gears…
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3mf file, screenshot of previews, and/or more info about your settings please
This looks like settings of 1 wall 0 infill and a narrow part cavity on the geometry… or it could be underextrusion from various possible sources… or it could be too low of temperature…
hoist control v6.3mf (78.6 KB)
Elegoo PETG, bed temp 80 then 70
print temp 260 then 255
have calibrated the nozzle & flow etc.
All layers are smooth and even
it only appears to be happening on what I am calling the front vertical wall…i.e. the face you would see if standing directly in front of the printer
this is the same issue I reported here
3mf file’s AWS chinese URL can’t be accessed (maybe outside of the great firewall??) Was that your link or did the forum do it to you? lol
That link sends to a .cn url “https://or-cloud-forum-prod.s3.us-west-2.amazonaws.com.cn/original/3X/8/6/868300e369cad460661e726689cf077c54ba0d42.3mf”
Can you try either fixing/rehosting the 3mf link outside of china… or listing out the settings overrides you have enabled from a default 0.20 layer height + “Generic PETG” filament?
I have no idea what is happening…
does this work https://drive.google.com/file/d/1LcPy9JYQAiSJFlTMV_Rid9TGHT8dBMz7/view?usp=sharing
another pic…I ran a knife through the faces and the layers just peeled off…other faces seem OK as do other layers although they can be peeled off rather more easily than I would have expected
Great, thanks
3 things stand out bigtime relevant to the problem:
- This seems very sus. Flow rate really shouldnt need to be adjusted that heavily, something else might be very wrong if that is your real needed flow value. If this flow rate is wildly off, it will WILDLY exacerbate problem #3’s layer squish. Recalibrate before going any further IMO
- I dont have experience with HF PETG but every regular PETG i’ve ever used has had better layer adhesion the slower you print it, and you got yourself a layer adhesion problem, so i would reduce this.
- You have it set to inner/outer/inner and more than 3 walls. Look at your preview (arrows on my pic) to try to understand why these would be sheeting off in layers. There is a literal, real gap being printed (at breakneck speeds, with likely low flow) and then when it comes in to fill that gap, it doesn’t seem to do so well. Try changing to inner/outer, so that the second/third/etc lines will ALWAYS be melted to another wall when they print. Or fix your flow before retrying with inner/outer/inner.
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wow…THANK YOU !!!..as you may have gathered I am quite new to 3D printing.
I have previously used the 0.08 extra fine layering and I dont recall those issues…but I hadn’t printed anything that high.
I moved to the 0.2 layering to drastically reduce the print times on items that dont need to be super fine and smooth
I will address these points and try again…but why would it seemingly only affect the front faces?
Why the front faces only, I’m not so sure. If you follow the preview’s playback you can see that of the 7 total wall lines, 4 of them are printed with air gaps around them, so those (IMO) underextruded lines just don’t connect side-by-side, but definitely connect top-to-bottom
This infographic isn’t quite perfectly applicable since you have more than 3 walls, but I hope you can see what would happen to the overlapping area if the lines were only 84% as fat. not great contact with walls, great contact with layer below, would form as a series of 1-line-thick vertical sheets.
FYI the .3mf download issue is forum related and will hopefully be fixed soon.
…which is EXACTLY the issue I have…hmmm
Now doing a complete everything re-calibration…the flow rate came out at 0.95, the flow dynamics at 0.25, still doing the others!
bl**dy hell…
I have completed all the various calibrations, tests, flow rate adjustments, volumetric speeds, flow dynamics, slowed the print speed down etc. … and it is STILL failing…if anything its worse as none of the outer walls are sticking 
attached link to the latest version with all the new settings and some pics
what AM I doing wrong??
edit… I noticed the top and bottom layers were wrong and have corrected them but I dont think this will affect the original problem of the walls not sticking to each other
…and I am still not getting notifications even though it says I will as I created this post
I dont have the most recent bambustudio installed (see: software lockout security theatre) but when I dump this into orcaslicer I see a few things:
-
The volumetric speed is now set 10x, to 250 mm3/s! While this is functionally similar to when you had it set to 24 (24mm3/s thru a 0.4 nozzle doesn’t become constrained until basically 600 mm/s speed) it probably is better to set it to a reality-based number. This number is measuring how much volume of material is being pushed thru the heater, 250mm3/s is like saying the extruder doing this job is capable of printing a benchy in 63 seconds!
-
Flow precision - because bambu printer profiles regularly make the line width WIDER than the nozzle aperture, means that the layer is squished down, and fills to the edges, like a slightly inflating balloon. That means that every molecule of underextrusion contributes exactly to reducing the width of how inflated that wall got. You also have precise wall selected. See this diagram for what precise wall does:
I said all that to say this - In this last test, are you only able to peel off ONE wall, or do you have many layers of wall flaking off still? If only the outer wall is not adhered - try again with A) more flow or B) precise wall off or C) both. I know your test said 0.95 but try 0.99 or 1.00 for a giggle. Being even EVER So slightly off in volumetric flow will cause those two squished lines to not kiss when precise wall is ON.
- Maybe someone with more experience using PETG-HF specifically can chime in. My wisdom I’m sharing is based off years of using PETG-regular from dodgy suppliers on ebay where slowing down always increases my quality and reliability. For reference, I run bargain dried PETG (kingroon brand) thru my A1’s at 245C/75C/10%fan, Flow ratios between 0.95-0.99 depending on spool, 100% shrinkage, 8mm3s volumetric flow, and in my speed profiles I use 60outer/80inner/100infill as speed limits
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thank you… I am using Oracslicer
yes, it is ONLY the outer layer and always the one nearest the front of the printer…if it was a box then the inside wall of the back of the box would again be affected
I did a smaller test piece (attached test 2) and stopped it before the top layers were printed…and it was the same again
![test 2|690x388]
excellent test setup. I think you’re still underextruding barely, and precise wall is a setting that punishes “under” a hell of a lot more than it is impacted by “over”
I used this…
Example shows
As we see in our test, the issues started at 18 mm from the base, and your starting speed was 5 mm³/s with a step of 1 mm³/s, so the calculation would be:
Volumetric Speed = 5 + (18 * 1) = 23 mm³/s.
And then we can use the previous equation to calculate the suitable speed that we can safely print with:
Print Speed (mm/s) = Volumetric Speed (mm³/s) / (Layer Height (mm) × Line Width (mm))
Print Speed = 23 mm³/s / (0.2 mm * 0.4 mm) = 287.5 mm/s
My defects started at 13mm so 5+(13*1)=18mm³/s
print speed 18mm³/s /(0.2 * 0.4) = 225mm/s which is what I set …I think…
ah… just re-read this and have set volumetric speed to 25 and printing speed to 250…oops
test 3 to follow