Oddly, since the latest firmware update, I’m having trouble with top layers.I’d been printing this filament for weeks with no issues.
Everything else is printing fine, just top layers are showing this (which I think is called pillowing?).
Any suggestions to try and dial it in? It’s Qidi Tech PETCF. (.6 nozzle)
Your infill is pressing through.
Try increasing the number of top shell layers.
Also try changing the infill to gyroid or some other infill pattern.
Both of these remedies should fix the issue.
You can also try turning on ironing that they will significantly slow down your print but it will ensure really nice smooth surfaces.
Thanks for the reply. I had previously tried both of those suggestions, and they made no difference at all. I increased top shell layers from 3 to 5, with no change, but also tried both Grid and Gyroid for the same results.
I’ve never needed Ironing in over 100 of these prints, and given the time that would add to each print don’t wish to start using it now - but I appreciate your suggestion.
Then in that case, the only other option is to slow the print and decrease the extrusion temp. This will cause the filament to harden quicker.
Have you tried enabling the new beta feature in the slicer called “don’t filter out internal bridges”? It’s specifically meant to help with pillowing. Caveat: not sure if it’s in BBL slicer, but it’s in orca slicer for sure.
I literally just switched to Orca and running a test print with essentially the same previously known working settings (just to see if anything different).
I’ll try that feature, along with @Olias’ suggestion above.
Thanks and will report back. Frustrating when you’ve literally nailed hundreds of prints and then something unknown changes.
Someone mentioned that a recent config update caused a quality drop and I thought it was in their head… Then I used some ASA, and the quality was significantly worsened (mostly cooling settings). When I look back on a different PC that I haven’t updated the profile configs on, they are different. So, unfortunately, we are going to have to troubleshoot some bad profiles for at least a little while. Not sure if the profiles are the only thing changed though. The problems I’ve been dealing with seem a little deeper than the settings I found updated. But the slicer settings can be used to fix the issues I’ve found so far. Hopefully they get things cleaned up and we can get back to “Easy Button” printing. The good news, PLA seems fine. I haven’t seen any issues with it.
You can avoid that effect by always copying the profile and then giving it your own unique name. Then nothing will change underneath you without you knowing it.
BTW… thanks for this thread. I hadn’t heard of the term “Pillowing”. But it seems to share similarities in the problem I was having with the ASA.
Pillowing - This 3D printing problem mainly arises when the top layers don’t have enough time to cool properly and insufficient materials on top , resulting in gaps and voids resembling a pillow.
For me the layer cooling time was way, way off. The profiles were different but they didn’t seem to make sense. What I found to fix the problem was slowing the Minimum layer time down along with the Minimum Print Speed in the filament’s cooling tab. The second was the setting that did the most good. With the current profile, the Minimum layer time is being overridden by the Minimum print speed. So having a 12 sec minimum layer time is absolutely useless if you have a minimum print speed of 20mm/sec. The minimum print speed is the floor, so if you have a small feature on the layer you can be depositing filament layers in 1 or 2 seconds when the filament needs more time to cool.
OK so switched to Orca, default Bambu PET-CF profile (which is producing the same results as my original modified profile). Increased top shell layers to 4. No different.
Will now try again with “Don’t filter out internal bridges” checked. No other changes.
I thought Minimum Layer Time slowed everything down proportionately, including speed. From what I’ve seen, it doesn’t finish early and then wait before starting the next layer. It’s all continuous, but it takes longer because of the minimum layer time (assuming it’s applicable, of course).
Wow, that does look terrible! I have to ask: have you re-calibrated the flow rate? It looks way off. Or temperature? Something looks very wrong there.
It depends on the features of that layer. The way it works is the minimum layer speed has a “minimum print speed” too. So if the minimum print speed is too high to meet the minimum layer time, the minimum print speed wins and overrides the layer time.
On something like a Benchy’s chimney where its only got 8mm to travel around the chimney, if you have a filament that needs 6 seconds to cool between layers, at 20mm/sec its going to be done in .4 seconds (meaning it will travel 8mm in .4 second at 20mm/sec).
This Bambu tutorial explains it well.
When the fan speed reaches the max threshold, and layer time is still shorter than the minimum layer time threshold, that means cooling is still not enough. So the last improving cooling method is slowing down to make single-layer print time longer.
You can enable “Slowing printing down for better layer cooling” and it will lower the printing speed automatically when reprocessing G-code to make the layer time not shorter than the minimum layer time threshold. However, after the print speed is reduced to “min print speed”, if it still exceeds the “minimum layer time threshold”, it will not continue to slow down. In other words, it can reduce the print speed to “min print speed” at most.
Ohh… for the record, I don’t think this is the OP issues. Just has similarities. I think NeverDie’s suggestion is a good place to start.
I have. But what’s odd is the “non top surfaces” are exceptional in quality/finish. Zero layer lines and deep black consistent colour. I would have thought that if calibration was off it would affect all surfaces, not just top?
Temperature has not changed since hundreds of successful prints, but I tried going +/- 10degrees C while printing which also made no difference.
I was focused on the top because of your pillowing title, but when I look back at your very first photo, it looks terrible even before it gets near the top. No offense. Just trying to be objective here. Interlayer bonding is bad. The holes look awful. Just a wreck.
I was about to say something similar. I use the System presets only as a starting point for my own calibrations. I calibrate every one of my filaments, so everything I use has its own User preset. They may be only a tiny bit different than the system presets, but they give me reliable results and they only change when I change them.
The system presets are replaced with every new version of Studio and sometimes just because Bambu wants to update the defaults.
This is part of the reason I avoid the “Custom” presets, besides the fact Bambu never really explained how they work or what their advantage might be. The Custom presets all “inherit” values from the System presets. If your Custom preset only changes one or two parameters, but then other parameters in the System preset change, I think your Custom preset will also inherit those changes. I really don’t want an “update” to change settings I’ve already fine tuned for successful prints.
Yeah, your issue is something weird with the cooling. You can see the top surface literally contouring the infill. So a 80-100% infill will fix the problem, but that’s wasteful. If NeverDie’s suggestion doesn’t work you can try a tighter infill pattern like Rectilinear, and bump up the infill to like 30-40%.
From what I see Rectilinear at 30% should do it. At least as a band aid.
One other trick, so you don’t waste all of your PET CF testing. In the slicer, before sending it to the printer, simply sink the model in to the bed so that it only slices 1-3mm under that top surface. That way you can test the setting and only use a little bit of the filament for each test. You could also just do two cuts and only print the section you want to test.
No offence taken! I’m just at a loss at what changed and trying to work through it objectively also. All input is appreciated. I’ll let this print finish and if no improvement (with previously mentioned changes) I’ll then throw everything out the window and start again - machine cal, flow cal, etc. The basics.
I’m especially interested because your filament in the one I want to try next.
Have you thoroughly dried it at high temperature? The directions are very clear about that. I just recently acquired a blast oven to do it correctly, especially for this filament.
