Bambu Slicer won't bridge painted surfaces, instead creates overhangs

[ErieQuiet]

I’m trying to paint a negative feature on the bottom of my models,
letters\numbers etc because I need text on both sides…
should be no issue but instead it turns what should be an easy bridge into a pure overhang…

to demonstrate, take a standard 20mm xyz cube… flip it upside down, and paint the Z

if I remove the painted surface it bridges the small gap just like anything else no problems

[SENTNTTOILET]

I also have this issue using 1.10.1.50.

Did you ever find a fix?

[ErieQuiet]

Only fix I found was to make a completely seperate part and position it where the bridge would be and paint it

Very broken

[SENTNTTOILET]

That is what I have found too. But this results in 3x as many filament changes for me.I tried painting just the surface that shows on the bottom, but it did the same thing.

[SENTNTTOILET]

Nevermind. I just have to tune how big it is and the location to the main model

Thanks! Hopefully they get this fixed.

[user_2502538637]

Hey Everyone. I posted this on another forum, but I will post here as well.

Pretty sure I found a decent solution. Bambu definitely has an issue in their slicing logic when changing color on a bridge. This needs to be fixed as this is a very common use case for the AMS in my opinion. Here is the solution I have found:

1. Create a cube modifier and scale it to cover the area you wish to paint. Adjust the height so that it is about 3 layers high. For me that would be 0.6mm since I am using 0.2mm layer height.
2. Move the modifier so that the bottom face intersects the area you wish to paint. My text is debossed 1mm and the height of the modifier is 0.6mm, so I moved the rectangle to 1.3mm on the world coordinates.
3. In the parts browser on the left side of the slicer, right click the modifier and change the filament to the color you wish to paint your deboss.
4. Change the slicer settings for the modifier to be 100% sparse infill. You may need to change the sparse infill type to rectilinear because some types are not compatible with 100% infill.
5. Slice the model, and this should generate a bridge instead of attempting to print walls over the gap.

I have included some photos below. The top photo is how Bambu slicer approaches the bridge without a color change (Works as expected). The following 2 photos are after the fix I described above. Let me know if this helps anyone and if I can further clarify above.

[AeonJoey]

First off, thanks both User above and ErieQuiet for your solutions, there still exists a huge caveat that neither workaround works if the model causing the non-bridging is painted. Nothing will work to make it bridge in the underside crevices and I’m baffled as to why.

I do have one tidbit to add however, if you extend the painting to the outer wall perimeter e.g. as in when doing layer color shifts, it will bridge regardless or any modifiers, if you cut the perimeter in half by painting and removing half of it, it will bridge about 1/4 of the side of the art with he perimeter extending to the wall. Bonkers logic happening. I’m honestly confused how I’ve gone this long printing multi color prints and haven’t run into this until now, but if the model is painted, NOTHING works. There is very messy workaround though using a hybrid of the two above:

1. erase the painting of the main model entirely so that it is a single solid color

2. Re-create the painted areas using modifiers as mentioned above, do this for ALL of the art in the entire piece (may be impossible for intricate designs, but for designs with indentations where they were painted with the fill bucket, those can be replaced with floating panels of changed color)

3. Performing these steps at first did nothing, even with the colors selected with numbers showing in the Objects tree - you must change the color away to something else and then back for each different element at least once for them to register, you’ll see the prime tower grow each time.

4. Once recreated, completely, the bridging will work.

   
   

   (edit: updated screenshots with easier to see colors)

[Virtality]

Yeah I love how this still remains a problem