Poor quality of overhang areas

Bambu Lab A1 Series Troubleshooting
1

Hi all,

I am relatively beginner und I a habe been using my new A1 with AMS-Lite over the last 2 months. I have learned much and I create and print some simple models myself.
My problem is the poor quality of overhang areas. Over the last months I have been using Elegoo PLA filamen and I was satisfied with the print quality except for overhangs. I have decided to use Bambu PLA Basic filament hopping that the quality will be better, but the result with Bambu filament was wors.
Please refer to the attached photos (white is Elegoo / gray is Bambu).

Note: Both prints in the photos were made exactly with the same settings (default profile 0.2 mm with tree supports).

Thanks in advance for your suggestions.

1

20250206_142001
20250206_1420011920Ă—1081 124 KB

20250206_122509
20250206_1225091920Ă—1081 104 KB

2

Try printing the model “upside down”

3

That would work for that print, but that was only test print for demonstration. With other prints hangovers are sometimes unavoidable

4

that’s just physics and the nature of FDM printing, you will never get a pristine underside of free hanging structures. You either need to reduce Z distance, then you get object scarring or live with those “strings”. Best is to solve this with the model itself, avoid those overhangs, turn it, print in multiple parts.

You can use dissolvable support filament, that allows you to use Z distance of 0 and 100% interface density. but its expensive, uses up much more time and filament an will still not be as pretty as the top side.

there are other 3D printer types than FDM that don’t suffer from this limitation, e.g. SLS

1 Like
5

I didn’t realize it was a test model.

6

Horizontal overhangs require proper settings and calibrations if you want acceptable results.
And acceptable here is still far away from perfect.

Create a solid support interface, not a grid pattern.
Adjust the z-gap distance to match until the first free hanging layer prints right on the support interface and not above it.
Use a compatible filament…
E.g.: PETG for PLA or if in doubt disolvable filament.
Set the bridging speed LOW - in almost all cases you get a bridging layer right on the interface layer.
Unless you go wild on the settings to make sure no bridging will be used you have to adjust the bridging as good as possible.

1 Like
7

Thank you all. I think I have now a good basis to build on for optimizing the overhangs