Combine stl files?

[Karel]

I was trying to print two overlapping stll files in Simplify3D, but only one file came out the slicer.
Did I do something wrong or is it not possible to combine stl files within Simplify3D?
If not, any suggestion how it could be done is welcome.

[CompoundCarl]

Well, the best way to do this is the boolean the 2 parts together in the original CAD package. But if you can't do that, then yes, S3D normally works fine assuming you set it up correctly.

If you have 2 separate STL files that you want to overlap, they just need to be 2 separate items on the models list. What you cannot do is have 2 meshes that are shoved together into the SAME single STL file with lots of overlapping and self-intersecting surfaces. That won't work, because you have told the software that is a single model, but in reality, it is not.

So just make sure each part is a separate item on the models list. You can use the Mesh > Separate Connected Surfaces option if you need to break up a larger STL file.

If you're still having trouble, post your factory file (File > Save Factory File)

[dkightley]

What you cannot do is have 2 meshes that are shoved together into the SAME single STL file with lots of overlapping and self-intersecting surfaces. That won't work, because you have told the software that is a single model, but in reality, it is not.

This is not strictly true, and I think Carl has forgotten the new Separate Connected Surfaces option (on Mesh dropdown) that was introduced in v3. I have the issue of separate meshes in the same stl file all the time as my 3D CAD package is not that good at Boolean logic. Using the option actually separates the meshes out and creates multiple models from them. And S3D does the rest by merging the meshes before slicing.

Take a look at this thread: viewtopic.php?f=9&t=4986&p=21599#p21599

[TylonHH]

Hi,
I have two object overlapping. Both should have different infill. But S3D is printing them seperat into the model.
You can see in the preview that the print is overlapping.

Check my FFF

[dkightley]

What you're seeing is exactly what you have asked for! The two models overlap and are printed by different profiles. The slicing will overlap!!

If you want the included part to have a totally independent infill, then you will need to create two separate shapes that do not overlap....ie in your example, one tall block and one smaller block with a hole in it where the tall block fits! Then, using separate profiles, you'll get the two different infills. This is exactly the same way that you set up a part to get two-colour prints.

[MartianAndy]

If you want to merge 2 STLs into a new STL, and then print that, try atomiccompiler.com (upload the STLs, use a UNION method, then download the result).

OpenSCAD can also be used for this but I've noticed that larger STL files often cause it to crash.