Lots of problems editing / merging complex STL files

[SilverHornet]

I'm trying to import a few high-resolution STL files and tack them together, as they've been chopped up for 3D printing. I've imported them as new files, and imported the lot into one design, but now that I've done the actual work of aligning them with minute overlaps for merging ... I find that I cannot in fact modify, merge, edit, or frankly do anything with them other than move them about. They are too complex to convert to bmesh, I've tried that route. Am I missing something obvious?

I've also tried using Blender to merge them, but I'm unfamiliar with it and the imported STLs are invisible except in 3D view mode, which lacks the object panel so I cannot merge them. That's a different problem entirely and I really don't want to include Blender in the workflow for problems like this if possible.

I also have access to Turbocad, but again I'd rather not involve it. I've tried importing there too and subtracting from a block so I can invert it into a solid object, but I have to do a silly route of TC surface -> smesh -> ACIS and invariably it crashes on one of the stages. Instability and a godawful plane navigation system are the main reasons I'm trying to move to Fusion 360.

My end objective is simply to make one STL file containing one editable object, which I can then make minor adjustments to, and finally set up CAM paths for a CNC router.

Thanks in advance for any advice or insights people can offer.

Edit: I have now found out why the Mesh workspace was unavailable - edit history had to be disabled. I'm currently reducing the triangle counts there and -hopefully- that will be adequate. I'd still very much welcome other's insights and experiences with this common problem though.

[jmc5378ZWDV9]

I use Freecad to convert all stl's to parts then export to step files which fusion360 can handle much better.  Install freecad, simport the stl file, then go to the part workbench.  Next select the stl in the 3D view and then navigate tot he Part drop down menu and select "Create Shape From Mesh",  depending on the complexity of the stl it could take a while.  Once it converts delete the original stl import and select the converted part.  Select export from the file menu and choose the step or file of your choice.

Hope this helps,

Jason

[TrippyLighting]

If the end result is to be used for 3D printing, then you possibly get better results using Autodesk Meshmixer, which is a software designed to work with .stl meshes.

fusion 360 does not handle meshes  well and generally what you are trying to do you should not usually attempt with a CAD software.

[Brady_Fulton]

Yeah, what he said 😉

[TheCADWhisperer]

Ok, let's cut the chase and end all doubt.

Attach image(s) of your geometry, or perhaps better yet - the original stl files.

[SilverHornet]

I did in the end give up and migrate to Meshmixer for the heavy lifting, horses for courses I suppose. It's a shame Fusion hasn't got more mesh features, and the STL import route is bonkers, but this is a viable workflow now I'm used to MM.  Thanks for the replies!