Import multiple stl files in different positions with the same absolute reference system

[IValdivielso 0]

Hello,

I would like to be able to import multiples STL files to the same session keeping their position with respect to the absolute reference system of the CAD.

Thanks a lot.

[Cuq 198]

Import every STL file in MeshMixer, export under 3MF format and load it into cura ?

Edited March 3, 2021 by Cuq

[tinkergnome 927]

13 hours ago, IValdivielso said:

I would like to be able to import multiples STL files to the same session keeping their position with respect to the absolute reference system of the CAD.

 

I think you're looking for "Merge Models" - this function aligns multiple loaded models in respect to their origin.

The way this works is: first load all separate parts, then select all (STRG + A) and "merge" their position (STRG + ALT + G).

 

https://support.ultimaker.com/hc/en-us/articles/360011738340-How-to-merge-and-group-models-in-Ultimaker-Cura

 

 

[GregValiant 1,248]

Typically each model is brought into Cura by Center-of-Geometry and each model would need the same Center-of-Geometry in order to locate them correctly relative to each other.  It is possible to use programs like Blender or 3D Builder to impart location data into the STL or 3mf.  I haven't played with that very much.

 

To fool Cura into becoming an assembly modeler I do the following.

My build plate is 230 X 230.  I create a build plate in the Cad program up to 230 x 230 x 5 with the top at Z=0.  My real models are above it and oriented the way I want.  The build plate gets merged with EACH model individually and then the model is exported as an STL.  The build plate now determines the Center-of-Geometry for each model so the 0,0,0 of each model is identical no matter what angle the real model is at, nor what any models Z height might be.

As in Tinkergnome's image, parts that are symmetrical about the Center-of-Geometry don't need a trick to fool Cura.  Assemblies often do.

 

These models were exported from AutoCAD as STL files and imported into Cura.  There isn't any location data in the STL's.  The flat rectangle was brought in first and occupies Cura 0,0.  Cura placed the others where they wouldn't interfere.  If each was moved to 0,0 they would overlap.

 

These are  the same models but each merged with a build plate.  They are spatially correct when each is moved to Cura 0,0.  The 5mm plates are now 5mm below the Cura Z=0.  They will print in their correct positions relative to each other.  In this example, because I chose to make the build plate the same size as the Cura build surface there is no room for a skirt or brim.  Adjustments in the size of the plate would need to be made to accommodate a skirt or brim.

 

 

An alternative to the above would be to simply merge the models before creating the STL file.  In AutoCAD, the models don't have to be touching in order to merge them.  The above models would have come in as you see them above but without the build plates.  Their center of geometry would be some random point - but it would work well enough to print the parts in their proper relation to each other.

 

As CUQ points out, it isn't always easy.

Edited March 3, 2021 by GregValiant