Reduce STL Wall Thickness

I have an STL whose walls sit somewhere between 1 mm and 5 mm, and I need the entire model uniformly brought down to about 1 mm without touching the outside scale, overall footprint, or fine details. In other words, I’m after an inward offset of the geometry rather than a global resize.

You’re free to use Meshmixer, Blender, Fusion 360, Netfabb—or any tool you’re comfortable with—as long as the result is:

• A clean, manifold, error-free STL
• External dimensions, hole spacing, and mounting points untouched
• Internal walls and cavities reduced as close to 1 mm as the geometry reasonably allows

I’ll run the finished file through Cura/PrusaSlicer to confirm the new wall report, so please keep the model orientation and origin identical to the original. If you see spots where 1 mm just isn’t viable (structural ribs, thin decorative edges, etc.), flag them and propose a workaround rather than scaling anything.

The task should be quick for someone experienced in surface offsets and mesh repair. Once I verify the slice preview shows consistent 1 mm thickness, we’re done. Looking forward to your expertise and a fast turnaround.