I've been trying to find a solution to a problem I've been having recently whereby the bottom layers of my print (1.2 mm; 12 layers) are either being compressed. over extruded or both. The problem results in the nozzle being dragged through previously extruded filament leaving deep groove marks and the bottom layers being risen/wavy, thus causing (I believe) the print layers to expand horizontally outwards
- Anycubic Chiron
- 0.1 mm layer height
- 200 °C hotends temperature
- 55 °C bed temperature
- 40 mm/s print speed
- eSun black 1.75 mm PLA
- Cura 4.4.1
It's less noticeable on less intrinsic prints but for my latest project, its becoming a real issue. The problem is that for the square holes for the buttons (of which there are a lot), the bottom layers are extruding (essentially elephants foot-ing) which is impacting the tolerances of the build (holes should be 13 mm to accept 12.5 mm square buttons but are coming out at ~12.7 mm only on the bottom layer, I've measured the walls of the square holes and they're coming out perfectly).
I've tried almost everything I can think of/find on Google:
- Levelling the bed (multiple times)
- Tried print temps from 190 °C to 210 °C (even printed a temp tower which confirmed printing at ~200 °C is correct for my filament (eSun black PLA)
- Calibrated the extruder
- Calibrated the Z-axis
- Set different horizontal expansion settings in Cura
- Reduced entire print flow rates (have tried 90 %, 85 % and 80 %); this somewhat worked but produced problems elsewhere in the print due to lack of material (skin overlap etc.)
- Used the 'modify settings for overlap' mesh setting to reduce infill flow & inner wall flow to 45 % and 55 % respectively for the bottom layers (up to 1.2 mm).
The last point in that list is where I've had the most success but it does leave a slight indentation around the outer wall until the full flow rate kicks in (i.e. >1.2 mm) and I'm thinking there may be other things at play that are causing the issue and I shouldn't have to do this reduce bottom layer flow so much if at all.
Has anyone seen this before?