How I built a tool that converts SVG files into 3D letter fabrication files (STL + DXF)

The problem

Every time a client wanted dimensional letters — for a sign, an
installation, a storefront — I hit the same wall.

Either I had to hire a 3D modeler, or spend hours in Blender
manually extruding paths, fixing normals, and setting up tolerances
for the acrylic slot.

Neither option was good. Hiring someone adds cost and back-and-forth.
Blender works, but it's slow and overkill for something that's
essentially a parametric operation on a 2D shape.

So I built FacLet3D.

What it does

You upload any SVG file — a typeface, a logo, any vector shape — and
the app generates:

• STL files for the shell and base (ready for 3D printing or CNC)
• DXF file for the acrylic face

You control:

• Wall thickness
• Base structure (outer wall, inner wall, heights)
• Acrylic slot dimensions
• General tolerances
• Live 3D preview in the browser

No CAD knowledge needed. No Blender. No modeler.

How it works under the hood

The core challenge was parsing arbitrary SVG paths — including
compound paths, holes, and nested shapes — and turning them into
watertight solids with consistent normals.

SVG paths can be messy: overlapping subpaths, mixed winding orders,
self-intersections. Getting clean geometry out of arbitrary user input
required a lot of edge case handling.

The base and shell are generated as separate STL files so they can be
printed independently or assembled. The acrylic DXF is offset inward
by a configurable amount to account for laser kerf.

Who it's for

• Graphic designers who want to hand off production-ready files without learning CAD
• Signage makers and print shops
• Makers with 3D printers who want to fabricate dimensional lettering

Try it

Free tier available at: https://faclet3d.factorgrafico.com

Built solo. Feedback very welcome — especially from anyone who works
with signage or fabrication.