Is there an existing issue for this problem?
Snapmaker_Orca Version
2.3.5
Operating System (OS)
macOS
OS Version
MacOS Tahoe 26.6.2
Additional system information
Printer
Snapmaker U1
How to reproduce
Open 3MF file.
Click “Slice plate”.
After the file slices, open the dropdown menu titled “Filament” and select “Fan Speed”. Or just print the file and notice the unevenly cooled layer lines marring your print.
Actual results
Certain layers of the print end up being cooled much faster than the rest of the print, resulting in unsightly surface quality.
Expected results
The Fan Cooling Speed overview (as seen in Preview) should look more like the Layer Time overview (pictured), with the speed of the fan corresponding to the time it takes for a given layer to print. Namely, for this print, the fan should not run at 100% speed for any layers.
Project file & Debug log uploads
2026-08-26-14-51-58.log.0.zip
Isopod, Dairy Cow (50%) x12 by Layers In Green — RECOLOR.3mf.zip
Checklist of files to include
Anything else?
I found while attempting to slice a different print that unchecking “Keep fan always on” eliminates the issue of the fan running at 100% on certain layers (at the expense of the print not receiving proper cooling over much of its surface), except then the fan speed will inexplicably drop to 0% on certain layers even though they fall below the minimum layer time for the fan to be activated. So I’m damned if I do, damned if I don’t.
UPDATE: Turns out that depending on the “Minimum layer time” setting, even turning off “Keep fan always on” doesn’t guarantee an absence of 100% fan speed layers. Note that in the screenshot below, only one of the objects has such a layer. I can’t fathom what the flying festering filament flakes is going on with these settings to cause such f***ery.
UPDATE 2 (8/27/26 20:54): I just upgraded to Snapmaker Orca 2.3.6, and if anything the fan speed glitches have become even more extreme and nonsensical.
Note how all four objects have layers where the fan runs at 100%, but one of them has a whole series of layers (beginning well below the others’) where the fan alternately runs at 100% and 20% speed, but only on three of the object’s four tallest parts.
By the way, here is the 3MF and log for this file, plus the gcode:
3mf, gcode, log – Seal, Harp Pup (35%) x4 by Kekreations.zip
Is there an existing issue for this problem?
Snapmaker_Orca Version
2.3.5
Operating System (OS)
macOS
OS Version
MacOS Tahoe 26.6.2
Additional system information
Printer
Snapmaker U1
How to reproduce
Open 3MF file.
Click “Slice plate”.
After the file slices, open the dropdown menu titled “Filament” and select “Fan Speed”. Or just print the file and notice the unevenly cooled layer lines marring your print.
Actual results
Certain layers of the print end up being cooled much faster than the rest of the print, resulting in unsightly surface quality.
Expected results
The Fan Cooling Speed overview (as seen in Preview) should look more like the Layer Time overview (pictured), with the speed of the fan corresponding to the time it takes for a given layer to print. Namely, for this print, the fan should not run at 100% speed for any layers.
Project file & Debug log uploads
2026-08-26-14-51-58.log.0.zip
Isopod, Dairy Cow (50%) x12 by Layers In Green — RECOLOR.3mf.zip
Checklist of files to include
Anything else?
I found while attempting to slice a different print that unchecking “Keep fan always on” eliminates the issue of the fan running at 100% on certain layers (at the expense of the print not receiving proper cooling over much of its surface), except then the fan speed will inexplicably drop to 0% on certain layers even though they fall below the minimum layer time for the fan to be activated. So I’m damned if I do, damned if I don’t.
UPDATE: Turns out that depending on the “Minimum layer time” setting, even turning off “Keep fan always on” doesn’t guarantee an absence of 100% fan speed layers. Note that in the screenshot below, only one of the objects has such a layer. I can’t fathom what the flying festering filament flakes is going on with these settings to cause such f***ery.
UPDATE 2 (8/27/26 20:54): I just upgraded to Snapmaker Orca 2.3.6, and if anything the fan speed glitches have become even more extreme and nonsensical.
Note how all four objects have layers where the fan runs at 100%, but one of them has a whole series of layers (beginning well below the others’) where the fan alternately runs at 100% and 20% speed, but only on three of the object’s four tallest parts.
By the way, here is the 3MF and log for this file, plus the gcode:
3mf, gcode, log – Seal, Harp Pup (35%) x4 by Kekreations.zip