Merge items Bambu Studio automatically drops to bed

[ansonl]

I have a 3MF file that has multiple object prepositioned at the exact printing heights and some objects are above the bed.

When I import the file and I choose not to import as 1 object with multiple sub parts, Bambu Studio automatically drops the pieces to the bed which makes the objects unprintable since I cannot restore the exact heights they should print at.

When the file is imported a 1 object with multiple parts, I cannot Split the object into multiple objects without Bambu Studio automatically dropping the objects to bed before I can Merge certain items together since the object is large enough that I need to split it into two beds.

How can I Merge my objects into collections before Bambu Studio drops them to bed? Bambu Studio seems to not support nested collections so I cannot merge parts while they are in the single imported object with multiple parts.

An example:
I have 4 objects
A
B
C
D

I want to group them like
Object 1 >
** A**
** B**
Object 2 >
** C**
** D**
So Object 1 and Object 2 can be on different buildplates

Bambu Studio imports them as
Object 1 >
A
B
C
D

I cannot achieve the grouping I want by splitting Object 1 and regrouping correctly before BS automatically drops the floating parts to buildplate.

[Olias]

I’m having a tough time visualizing what your objective is. Can you kindly post an annotated screengrab of what your model looks like and exactly how you want it to look? If you don’t know how to do screengrab annotation, there are 1,000 of tutorials on YouTube. However, if you care to upload the 3MF file, I can take a look at the actual model and maybe help you there.

If I were to guess. Based on your description, you are missing the critical step of adding these objects into an assembly. This is important step to creating a geometry that the slicer will treat as a solid object. I say that because if you are picking up an object and it is falling, that means it is not anchored to the bed. Using the assembly feature is how to do this correctly.

[ansonl]

Hi Olias!

I attached a few screenshots showing the issue.

In the model shown the green pieces are two separate objects that are positioned next to each other and each green object has a blue object that is positioned at a specific height in the 3MF. Making 4 objects total where 2 objects should be grouped together.

The first screenshot is what happens when I choose to not import as a single group with multiple parts. In the next screenshot I moved one of the green objects so you can see that there is a blue object hidden inside it that was dropped down to the build plate when imported (which is not what I want)

In the third screenshot, I import the same single 3MF file with 4 objects and select Yes to import as a grouped object. The blue objects are now kept at the correct height and not dropped to the bed. However I cannot separate and regroup the bottom green and blue objects without using the Split feature. Once the the single group is split I cannot regroup them at the correct position because the pieces are dropped to bed. Splitting leads to screenshot 1 instantly.

Ideally the final objected get grouped like the below so that I can print each group of green and blue objects separately and scale them, etc.

The sample 3MF file is in the issue I opened on github https://github.com/user-attachments/files/18548800/CA-sqrt-dual-transparent-v2-hex200scale-test.zip

My current workaround is the create multiple original 3MFs one for each grouping and then individually import them and click Yes multiple times (20+ times since there are a lot of pieces).

In Cura there is a feature to disable auto drop to bed so the user has a chance to Group objects together before doing anything else.

[Olias]

Ok. Thank you for posting this level of detail. It will drastically reduce the back and forth guesswork and allow for a more concise illustration.

Simplified illustration

Here is an animation that shows what is happening. The yellow model are two objects inside an assembly. The second two are the same objects as independent models. You can see how they behave differently when using the (M)ove command one tries to pick up one vs the other. In the yellow example, because the cylinder is part of an assembly, the lowest object(cube) in that assembly acts as an anchor to the build plate. In the green model, the cylinder just falls to the plate.

___________________________________________

What you appear to be experiencing is that you are caught between the automated function upon import of importing as a group versus independent objects. As you’ve seen firsthand, neither yes or no option works well if you want to get more granular control.

So the method I suspected you may not be employing, assemblies, is the better method to achieve what you described.

---

There are many other methods but this is probably the easiest to explain in a forum post. If this does not work, please let me know why and we can try another approach.

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To restate what I believe your objective is, you want the rivers to lay on top of the topographic maps. If I misunderstand that, please correct me.

The first thing we have to do is repair any non-manifold objects. Look for the error symbol

This happens when the 3D mesh does not convert cleanly leaving holes in the model. This will break a print in unpredictable manner. Do not be surprised if this takes several minutes of computing time to fix.

Separating the models.

If I understand you correctly, you want to essentially create two interlocking “puzzle” pieces that will print separately and then snap together after print. For this you want a consistent bottom layer height. Your current options are interfering with that.

TL;DR – This is the briefest way I can explain one approach.

There are probably five or six different ways to achieve this. As stated above, I believe this option is the easiest to explain.

1. Clone the model.(CTRL-K)

2. Delete the parts of the model in each clone assembly which are not wanted thus isolating the mating land mass and river system to each puzzle piece. So 004 becomes one assembly and 005 another.
   

   

3. This will create this problem. The two pieces are now at different heights:

Note: Color changed for illustration purposes only to provide contrast.

Since this is now part of an assembly, you can independently move the elevation using the (M)ove tool.

While I admit that this method is tricky and it requires some ninja mouse skills, it is the most straight-forward way to manipulate the model. Make friends with the CTRL-Z hotkey(undo), this will become your best friend during trial and error(CTRL-Y is redo if you change your mind).

An alternative, if the mouse movements are too tricky or god-forbid you’re a glutton for punishment and are attempting this on a a MAC with trackpad😉, you can use move tool and dial-in the layer heights manually. Painful? Yes, but an alternative to the mouse.

Here is the completed exercise file. I’ve never used this site so good luck and use at your own risk, there may be tons of tracking cookies but your file is too large to upload here. (37MB)

Download CA-sqrt-dual-transparent-v2-hex200scale-test- Example #1 - final.3mf...

[Olias]

BTW: I should have stated at the onset. DEM mapping using the USGS website has been a hobby of mine since the USGS started publishing models for download in in 1995.

There are ton of better resources on the web which will allow one to enter latitude and longitude and generate an STL file. I’m not sure where your model originates from but unless you are working for a company that is providing detailed hydrography and topographic mapping services, if all you want is a 3D model, here is just one site that will let you dial in the part of the globe you’re interested in. if it’s in North America, pretty much most of the land mass has been mapped.

Try it out.

Create 3d printable STL models from any place on Earth - map2stl.com

If not, try out this site where you can upload the DEM files directly and it will rasterize them into an STL although it may require more refinement of the model itself such as stretching the elevation to create more vivid details.

Heightmap to STL Generator — Dom Riccobene - Official Site

[ansonl]

Thank you for showing an alternative method with Cloning to copy of the assembly quickly in memory instead of reimporting each time. That will probably save me some import time (although I then need to delete all the other pieces each clone if there are lots of pieces)!

Do you know if there is a way to group objects into an assembly (3MF collection) in other 3d software prior to importing into Bambu Studio? I think that may be a way to quickly rearrange the object groups so that the correctly grouped model can be imported only once.

I tried to use Collections in Blender but the 3MF addon doesn’t seem support putting the grouped objects in an actual 3MF collection at this time.

[Olias]

@ansonl

Do you know if there is a way to group objects into an assembly

If you happened to have Windows 10 and if you loaded 3D Builder(free utility) when it was available(prior to Microsoft removing it from their store) it will still be on your system. 3D builder is a utility that will allow one to edit STL files and among other things, arrange them on a surface. You can then export to a 3MF file. It is arguably the easiest program to use.

Outside of that free program, TinkerCAD is the next program that could help but it does have a small learning curve.

From there, you’re now into a steeper learning curve with programs such as Fusion360, OnShape–both CAD programs–and to a lesser extend, Blender can also do the job. But these last three have steep learning curves.

[ansonl]

I figured out how to group (assemble) objects together before importing to Bambu Studio/OrcaSlicer. In Blender you can create an Empty object and either

• Drag your objects into the Empty to group them together.
• Select the objects to group together and select the Empty last. Then Ctrl+P > Parent under Object.

Now you only need to import a single 3MF file with all your pregrouped objects together and they are in multiple assemblies. Not the solution to the original question of disabling drop to bed but it’s an acceptable work around that saves time.