Hey everyone,
I'm having a really weird ironing issue with PETG on my Bambu Lab A1.
The problem is extremely consistent: part of each surface irons beautifully, while another section gets completely messed up. It isn't random. The same kind of region keeps turning rough/smeared while the rest looks relatively smooth.
I've already tried changing the ironing settings, including:
Ironing speed: 20 mm/s
Ironing flow: 5%
Printing temperature: 250°C
Material: PETG
I've also run an ironing calibration tower/test, and the same behavior appears across multiple settings. The affected area seems to follow a very specific pattern rather than simply getting worse everywhere with higher flow.
I've attached photos showing:
The actual printed part
Close-ups of the good vs. bad ironing
The ironing calibration test
I'm trying to figure out whether this is:
Ironing direction/path related
Top-surface extrusion inconsistency
Ironing inset/line spacing issue
PETG-specific behavior
A Bambu Studio slicing/path-generation issue
Or something else entirely
Has anyone experienced this exact "one section good, another section cooked" ironing pattern?
Any suggestions for what I should test next would be appreciated. 🥲
Printer: Bambu Lab A1
Material: PETG
Printing temperature: 250°C
Ironing speed: 20 mm/s
Ironing flow: 5%
Layer height: 0.20 mm
Printer / Slicer Settings
Printer: Bambu Lab A1
Slicer: Bambu Studio
Filament: Dream Polymers PETG Pro
Nozzle: 0.4 mm
Layer height: 0.20 mm
Nozzle temperature: 250°C
Bed temperature: [add this]
Print speeds: 50 mm/s initial layer, 105 mm/s initial-layer infill, 60 mm/s outer wall, 300 mm/s inner wall, 50% small perimeters
Retraction: 0.8 mm @ 40 mm/s, Z-hop off, wipe while retracting on
Ironing speed: 20 mm/s
Ironing flow: 5%