STL to Lathe-Ready STEP

I have a set of medium-sized parts (each roughly 10–50 cm) that currently exist only as triangulated STL meshes. They need to be machined on a CNC lathe for a series of custom projects, so I must receive a single, watertight STEP file for each part—free of faceting, noise, or broken edges.

Automatic mesh-to-BREP tools have already proven inadequate; the geometry has to be redrawn with smooth, continuous NURBS surfaces suitable for precise turning operations. Dimensional fidelity to the original STL is important, but the surface finish takes priority: basic, perfectly smooth contours without unnecessary micro-facets or decorative detail are all that’s required.

I will supply:
• The original STL files
• Reference dimensions where critical

You will:
• Rebuild the parts from scratch when necessary, rather than relying on direct conversion
• Produce clean, overlap-free solids that import into Fusion 360 / SolidWorks without errors
• Return a separate STEP (or STP) file for each part, ready for immediate CAM tool-path creation on a lathe

Acceptance criteria (reviewed on delivery):
1. Opens in Fusion 360 with no healing prompts
2. Surfaces show as analytic (cylinders, planes, etc.)—no mesh bodies remain
3. Key dimensions match the STL within ±0.05 mm
4. File is a single closed solid body

If this is within your wheelhouse, let’s get started—I can send the first STL right away.