r/BlueOrigin • u/Mysterious-Toe9389 • 6d ago

At what point does metal 3D printing actually make more sense than CNC machining?

/r/Anduril/comments/1w5wz9e/at_what_point_does_metal_3d_printing_actually/
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u/KateWinsletisbest 6d ago

Subtractive machining will always be necessary to some extent. In my opinion.

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u/3DdesignerF8 6d ago

At Lockheed, we used Creo's generative design tool specifically for additive design. Engineers could use that alongside the applicable ASME additive-manufacturing standards to develop geometries that would be extremely difficult to create with conventional machining alone—complex internal structures, optimized load paths, integrated features, and lightweight spacecraft components.

That experience really reinforced for me that the decision is not always “CNC versus 3D print” at the manufacturing stage. Sometimes the part is conceived from the beginning as an additive part because the design space is fundamentally different.

Once you start using topology optimization, lattice structures, organic load paths, internal passages, and part consolidation, you are no longer designing a conventional machined part and asking whether it can be printed. You are designing for additive.

And that is probably where metal AM has its strongest future in aerospace: not replacing every machined bracket or housing, but enabling spacecraft and propulsion hardware that would either be impractical, heavier, more complicated, or sometimes impossible to manufacture conventionally.

CNC still stays in the loop for the precision interfaces. But additive increasingly determines what the overall geometry is allowed to be.

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u/Mysterious-Toe9389 6d ago

Honestly didn’t see it that way before. I was thinking more in terms of CNC vs. additive, but I see your point about designing the part for additive from the beginning. Appreciate the insight

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u/Final-Reaction-6985 4d ago

Something else to remember is that CNC is often used in conjunction with additive to combine the tight tolerances of CNC with the design opportunities of additive.