Modifier question: How to expose infill on sloped top surface?

[ElEsido]

Hi all

I want to print a small loudspeaker in two parts that stack one on top of the other and pour resin into it. For that I will use gyroid infill and don’t want to print the top layer of the bottom part and the bottom layer of the top part, so that the resin can flow through both printed parts.

The mating surface is sloped and I can’t modify it as to have no top layer. Just for testing I flipped the object on its side so that one of the sides now is a horizontal top layer, and it works (first two pictures). But it does not work with a sloped top surface (second pair of pictures).

Would anybody know a setting that solves this, please?

Kind regards,
ElEsido

[JonRaymond]

Can you not simply use the rotate command to align the surface of the modifier to that of the sloped top?

[ElEsido]

Thanks, unfortunately that does not work - I must be doing something wrong…

[ElEsido]

Settings:
Quality:

Strength:

Speed:

Others:

And the modifier has the following different setting:

[JonRaymond]

Try 0 for “Wall loops” on the Modifier. The sloped surface has one wall loop in it.

[ElEsido]

Thanks, that removes some of the layers, but not all.

And is it normal that the modifier cube gets its own wall layers?

Settings of the mod cube:

[ElEsido]

Same with my own modifier shape from Fusion 360 rather than a cube shape from Bambu Studio- That, too, generates its own wall loops and does not remove all top strings.

These extra wall loops from the modifier object should not be there as they will contain the resin in the top part and prevent it from flowing into the side walls.

[Lexi]

Change the “Internal solid infill pattern” to “Gyroid” .

[ElEsido]

Thanks, but that option is unfortunately not available.

Whenever there is a different wall number between the main object and the modifier cube, Bambu Studio inserts a wall around the modifier cube that separates the infill space from the main object from the infill space of the modifier cube. Is that expected behaviour? It’s obviously not ideal for pouring resin into the object.

[Lexi]

You are correct. My apologies.
I thought it was an option.

[Lexi]

I believe I am able to do what you are looking for.
I created a primitive cube and cut it on an angle to represent your model.
I then created a modifier cube and matched the top angle and imbedded into the cut cube.
I only made changes to the modifier object to open the top angled wall:

Is this what you are trying to accomplish?

One more thing of note:
This was all done in Orcaslicer. I haven’t used Bambu studio for quite a long time.

[ElEsido]

Thank you, Lexi!!

The idea is to fill the body with resin, to it should be able to flow through the opening into the entire body. If you fill the orange triangle with gyroid infill you should see what I’m trying to achieve.

I would upload my models, but they are fusion360 files and I can only share images.

[ElEsido]

Orca does a slightly better job and indeed removes the top layer. But, like Bambu Studio, it introduces a wall around the modifier cube hat separates the modifier cube’s internal space from the object’s internal spare, so the resin would not flow from the “open top” part into the side walls.

I guess I’ll just print it without modification and drill a couple of holes into it.

[Lexi]

Maybe I don’t understand the scope of what you’re trying to accomplish.
I don’t have the exact model you are using, but when I slice this, I could pour a liquid into next to the walls:

I just resized the modifier to almost touch the outside walls.

[Lexi]

Oh. Maybe you are talking about the wall toward the back where they interface.

If that’s the case, you could always design a tool (STL) in F360 to use as your modifier.

I just picked a random STL to use as the modifier shape.

But in your case just design the shape you want to be slightly smaller than your walls to expose them.

Does that make sense?

[ElEsido]

Thanks so much, Lexi, for trying to help me.

I think there is a bug in Orca and Bambu Studio that does not let me do what I want to do. Let me explain:

The following is the bottom part of my loudspeaker sliced without any modifications. A part with a matching recessed wall will be stacked on top.

As you can see the internal space of the walls and the upper surface is connected (red hand-drawn lines). I now want to remove the upper surface (blue hand-drawn markings) so that the resin can flow from the part that I will stack on top (which itself will have an open bottom to let the resin out) into the lower part that you can see.

This is the slicing tool; one wall thickness thinner than the part, as you have suggested.

This is the result of slicing with the following settings of the modifier:
Top shell layers = 0
Wal loops = 1 [same as the main part]

You can see that the internal space inside the top and the walls is connected and uninterrupted - this is good - but there still is a top layer (blue hand-drawn markings). According to the orange colour, the slicer considers this as a wall loop. So let’s set the wall lops of the modifier part to 0:

Now the top is open - fantastic - but the slicer has introduced a new “wall” at the lower end of the modifier (red hand drawn markings) that divides the internal space of the side walls in two, which will constrain the flow of the resin.

Adding
Bottom shell layers = 0
Infill/wall overlap = 0
Minimum sparse infill threshold = 0
to the modifier object’s settings does not eliminate the creation of this divider.

I think that this is a bug; the slicer should not create walls at the edge of the modifier object when the number of walls of the modifier and the main object differ.

[JonRaymond]

Have you considered trying to use multiple modifiers instead of trying to do it with just one?

[ElEsido]

Thanks, but I don’t see how I could add another modifier, that option disappears when there already is one:

Also, i assume the second modifier would have its own walls, too.

I guess the solution is the modifier with 0 walls (which divides the internal volume of the main object’s side walls) and a drill or knife to address that divider.

[Lexi]

Right click the main object (the Speaker Bottom) above the one you have selected and you can add as many as you need.

[Lexi]

There won’t be walls where the modifiers overlap each other.

It’s a crude way of doing it, but it could work.

A better way would be to design the modifier tool in F360, using your model as the template.

Design it so it is scaled and the wall thickness (you want) is smaller than your model. Make sure the top pokes out higher to open up the top of your model.

Save the modifier tool as an STL, position it where you need it and set the walls to 0 on the modifier tool.