How do I stop Studio from removing surfaces between parts?

Hello everyone! I print a lot of raised text on flat surfaces to make plaques and signs and such. I am exporting the model from Fusion as one part with multiple bodies (each letter of text is its own body) and splitting the text into separate parts after I import into Bambu Studio. This gives me granular control over how the text is printed. It works pretty well for the most part except for one major issue. The problem is Bambu Studio removes the top and bottom layers between the text and the object I am printing on like they are one part. It’s inserting solid infill where text will be instead of completing the top surface with the top surface pattern I’ve specified. I want it to print a complete top surface like a sheet of paper before it prints the text.

I have tried everything to get this to work. The best I’ve been able to do is match solid infill pattern and line width to the top surface pattern but this doesn’t fix the core issue which is solid infill and top surfaces are printed at different times which leaves all sorts of surface defects created when the nozzles prints around solid infill.


I’ve tried detect narrow internal solid infill.
I’ve increased minimum sparse infill threshold with limited success. It doesn’t work on solid infill.
I’ve reduced the number of walls which works on thin text but not big text like in the pics.
Modifiers don’t have any effect on top or bottom surfaces between parts.
I have had to scrap so many parts because of this problem. I would appreciate any help or suggestions.

Thanks!

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Have you tried using the Boolean mesh tool? It will composite the STL mesh into one model. This may or may not answer your question, I have not tested it under those circumstances.

The issue here is of course you will have to resort to controlling the colors by layers not by object.

First Create an assembly and position your objects.

Then while the Boolean tool is active, you will have to select the object in the view window, the object menu is buggy and selecting there will often deactivate the tool. You’ll have to repeat this for each letter. Pain in the ass? Yes, but it will allow more control in “some” circumstances and may be worth a try.

The issue here is of course you will have to resort to controlling the colors by layers not by object.

If the backside face of your text is line-to-line with the top face of the underlying surface, you have two intersecting sets of polygons. The slicer can’t slice it that way, it makes a choice of which face to prioritize and apparently the code is written to give the face on the upper-most object the priority. Which kind of makes sense.

Move the text off the underlying surface by something like 1/2 of your layer height and see what happens. The slicer might complain but it’ll should still slice it and it should print just fine. Like when an overhang sticks too well to the underlying support, only more so.

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Hi Olias,
Thanks for the reply, but I don’t want Studio to treat the text and object as one mesh. It’s essentially doing that now. I want it to treat the parts like objects but hold their position and orientation. I want the text to be printed on top of a solid object.


Hi RocketSled,
Thanks for the reply. I will try that now.

It looks like studio fills any gap up to 1 layer height which is odd since I have the resolution set to 0.001mm. Once I get to 0.15mm it leaves the space but it’s too much. I wish studio would allow the objects to hold their relative positions like parts.

Yeah, and the gap will be in the shape of the overlying text. But it should be above the top layer of the underlying surface. It isn’t?

Resolution effects XY but not Z. Z resolution is defined by layer height.

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Maybe make the text a totally separate object and “shim” it. It might be enough to have a really small diameter cylinder extending from the underside of the text to the build plate. That way, Studio won’t snap the text to the build plate surface. Make the “shim” as long as the distance from the build plate to the top of the sign surface plus a teeny bit more. Maybe it’s small enough diameter the slicer ignores it completely, but it should hold the geometry up just the same. If the slicer does want to slice “around” it in spite of an infinitesimal size, at least you’re just looking at a small “dot” and not the larger disturbance you get from having the outline of the entire letter etched in to the top surface. And any defects would be dead center under the letter, completely invisible.

Make sense?

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The defects you mentioned on the top surface under the text is a known issue Bambu is working on. Their recommended workaround for now is to turn off single wall on top surface. It somehow fixes the issue.

If I understand his problem correctly, the overlying text casts a “shadow” on the top surface below it. Instead of the top surface being uniform single lines, it’s interrupted by the imprint of that “shadow”. If the overlying text wasn’t printed at all, the top surface would have a pattern that outlined the text. He wants to get rid of that effect.

As long as the two faces are in direct contact, the slicer has to choose one or the other and it’s picking the one that’s higher in the Z order. Wall count shouldn’t change that… but I’m too lazy to go check for myself so I’ll be anxiously waiting to find out if it does. :slight_smile:

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It does make sense. However small dots can be just as bad as large outlines because the defects aren’t the dots themselves which are covered up. The problem is the top surface pattern is interrupted by the dots and internal solid infill of the text. when using mono tonic line for top surfaces pattern, the nozzles stops the pattern when it hits a dot or any solid infill and causes noticeable differences in surface finish especially when printing with silk. This effect is amplified when the pattern is run detailed text and can really make a mess.


This is what happens when the nozzle has to reverse direction for one of those dots. All patterns are Archimedean chord.

Make the “shim” really, really small (consider increasing your resolution slightly). Below some limit the slicer has to ignore it for slicing. But it can’t ignore it for positioning the geometry on the build plate. Doesn’t matter how small the shim is relative to what it’s holding up since there are no physics involved, just “how far can this vertex be moved before it is below the build plate?”.

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This worked for a while on thin text until I upgraded to 1.9.xx. But now it doesn’t.

Did you try downgrading to the previous version?

I stack text on top of a flat surface with a tiny gap between the text and the surface
0.08 mm usually works.

OK. So if I understand you correctly. You want the following:

  1. A smooth plate with an unblemished solid surface
  2. An object to lay flat on top of the plate that does not interact with the pattern of the plate below.

The whole model. The text was using the Embossed text tool in Orca.

Note that this print was done with two dissimilar filaments which normally I would have never done. Also, this is using 0.28 layer height and the disk is only 60mm.

This was done completely in CAD

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I figured it out!! I should have gone to bed a while ago, so I will post some screenshots and pictures tomorrow and better instructions.

Fusion

  1. Make a sketch on the base part and use the text tool
  2. Right click the text and select Explode Text to convert it to a sketch
  3. Make an internal offset of the letters equal to your line width (0.4mm nozzle : 0.4mm offset)
  4. Extrude the outline to half your layer height. (0.2mm layer height : 0.1mm). Make sure to extrude it as a new component in the Extrude dialog box.
  5. Use the same sketch to Extrude the full letter, but make sure to activate the new letter component before extruding. Also make sure to start the extrusion on top of the outline.

Bambu Studio

  1. In the objects tab, select the color you want for the text
  2. Use Classic, not Arachne. Arachne has defects on the top surface in the slicer preview.
  3. Print it! It will print the top surface perfectly, and the next layer will print the full letter. Since the outline height was less than the layer height, the outline layer is not printed.

Hi SimEyeSee,
Thanks for diving into this so deeply. I didn’t mean to make anyone else lose sleep over this, but your efforts are definitely appreciated. I looked at your recommendations and think I you’ve hit on the primary cause: Classic vs Arachne.
I’ve defaulted to Arachne for text for so long I forgot to consider it as a possibility.

Changing the wall generator to classic does remove the solid infill between the text and subsurface in most cases. I still need Arachne on parts with very small text (smaller than 4mm) but for this particular Item, classic gives me exactly what I am looking for.

Thanks!

I think changing Arachne to Classic is good enough for the text you are dealing with in your later images because they are so thin, but for the thicker, solid text like in the image of your first post, the other steps I mentioned in Fusion about making the outline layer is also needed.

So many people including myself have dealt with this text issue. The issue has been present for years. I was looking into it and trying different things, and then when I started going towards the solution I found, I thought that I was finally on to something so wanted to complete it before going to bed or it probably would have just kept me up thinking about it.

I modified one step in my post above, make the offset width equal to the nozzle line width, don’t add 0.1. When I was originally doing tests, I added the outline without the solid layers on top, and it was too thin for Classic so it was ignored. I must have changed or clicked undo until it was back to 0.4 before I added the solid layers. I noticed this morning that my offset was 0.4, so I tried using 0.5 and it has the disadvantage of actually making the first layer just the outline, whereas 0.4 offset makes the first layer the full solid letter.