Hello,
I have an issue for a few days and I finally discovered that the slicer is the main perpetrator for me.
I’m trying to print something that has overhangs which should be fine, however, the printer speed is way too high for these areas, especially when compared to an overhang test print.
Adding screenshots below.
I tried a bunch of stuff, nothing seems to fix this. I even went ahead and modified the volumetric speed of the filament to 3mm/s from the default of 13 thining that most likely it will print the overhangs with 1mm/s. It didnt. Other than a painful slow base, it still failed.
Print part:
Overhang test:
Filament cooling settings:
For me this difference looks like a bug - should I report this on github?
– LE
After checking this in Orca Slicer, I’m quite sure it’s a slicer issue. The same project file imported looks like this on the Speed view:
It could be a bug…
Like the slicer thinking those connected parts are close enough to not cause any overhand issues.
I might be mistaken here but based on my experience with weird bugs I might say this:
Bambu is all about speed with quality often second best in terms of consideration for print profiles.
IF Bambu made this mistake I suspect than there might be a fix after all - or a workaround to be precise…
Could it be that the slicer won’t recognise those overhangs because the LAYER TIME is higher than what it takes to make the filament curl up ?
In the filament setting check the LAYER TIME against your slicer preview 
If the problematic overhangs take longer to print per layer than the set layer time you found your problem/bug.
Let’s say the layer time is at 4 seconds.
Increase the layer time to just over what it takes to print a layer of these overhangs.
If that makes a big difference you might have a workaround until Bambu fixes things properly.
You can also play with the Cooling Overhang Threshold, default is I think 50%.
If you reduce that to less than what the layer overhang of new layer is the forced cooling shall kick in.
Meaning the fan speeds up and unless Bambu created two bugs the print speed should also go down a little bit.
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This did the trick. Increasing both values for min and max by 100% added ~3 hours extra to the initial 7 hours print time and in the speed graph things look like this now.
Also, I increased the filament max fan from 40% to 90%, hoping to get less sag.
The Cooling Overhang Threshold is 90% but i’m not sure it kicks in correctly. While watching it print this section I’ve never seen it over 40%.
Fingers crossed for no spaghetti. Thanks !!!
Glad to be of help 
Even more that you managed to get the print coming out the way you want it.
I had a similar issue. Changing the wall generator from Classic to Arachne fixed my issue, it allowed the overhangs to be detected, printed and cooled properly. I also changed this
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If anyone is still having this issue, I use Orcaslicer and have been beating my head against a wall for a while that the filament setting for cooling overhangs did not seem to do anything. I just discovered that if you turn on slow down for overhangs in the print settings and then just set all the ones you don’t want to slow down to 99% it causes the settings you put in the filament for overhang angle cooling to all of a sudden work. I don’t know if that exactly fixes the issues here, but I know that Orca is based on Bambu, and I hope it helps.
