Closed contours become faces, faces become a solid
CADverter reads the DXF into its 2D drawing model — lines, arcs, circles, ellipses, splines and polylines on their layers — then looks for closed contours: chains of entities whose ends meet. Each closed outer contour becomes a face; a closed contour lying inside another becomes a hole in that face rather than a second part, which is how a washer comes out as a ring and a plate with bolt holes comes out with the holes through it. The faces are then swept into a real B-rep solid by the OpenCASCADE kernel.
Extrude a thickness, or revolve around an axis
The panel offers two sweeps. Prism extrudes the profile by a thickness you type, optionally centred on the drawing plane so the sketch sits at mid-height. Revolve spins the profile through an angle — 360° for a turned part, less for a segment — around the drawing’s vertical axis, which is how a half-profile of a bottle or a knob becomes the whole object. Arcs and splines are swept as exact surfaces, so a revolved arc is a true torus patch, not a stack of facets.
When a profile will not close, the panel says exactly why
Drawings drawn for plotting are rarely watertight. Rather than reporting failure, the findings list names the problem so it can be fixed at the source: which chain is open, how wide the gap is and where it sits, or the point at which a contour crosses itself. A gap of 0.02 mm at a known coordinate is a two-minute fix in any CAD tool; “could not build solid” is an afternoon.
CADverter does not silently weld gaps shut or drop the offending chain, because a profile that was quietly changed produces a part that is quietly wrong.
Units come from the DXF, the STL gets millimetres
The reader honours the drawing’s $INSUNITS header — inches, millimetres, metres and the rest — and converts to millimetres internally, so a 2-inch profile extrudes to a 50.8 mm part. STL cannot record a unit, so the file is written in millimetres and the panel says so. A DXF with no $INSUNITS at all is taken as millimetres; check the bounding-box size shown in the viewer before you commit.
STL is one target; STEP is the other
The solid the extrusion builds is exact geometry, so writing it as STEP or IGES loses nothing — curved walls stay curved, and the part opens in CAD as a proper body. Write STL for the printer, STEP for the person who will modify it, or both from the same panel. 3MF, OBJ, GLB and every other 3D target are also available.
Which DXF files work
Any DXF that carries 2D entities: exports from AutoCAD, LibreCAD, QCAD, Inkscape, laser-cutter software and CAM packages. A DXF that contains 3D solids or meshes opens as a model instead, and CADverter decides by looking inside the file rather than at its extension. Text and dimensions are ignored for the extrusion, since neither is a profile. SVG, PDF and Illustrator drawings extrude the same way.
Nothing is uploaded, and you can watch that being true
The DXF reader, the profile analysis, the kernel and the STL writer all execute in this tab. Open the Network panel before dropping the file: after the page assets and the one-time kernel download there are no further requests. The production build is tested for exactly this — zero external requests across an open, convert and download.
DXF to STL questions
My outline is made of many small lines — will it close?
Yes, if the ends meet within tolerance. CADverter chains entities end to end regardless of how many there are; a chain that stays open is reported with the size and position of the gap.
Can I extrude several separate shapes at once?
Yes. Every closed contour becomes its own body (or a hole, if it lies inside another), and all of them are written into the one STL or STEP.
Does it work with SVG or PDF drawings too?
Yes — Make 3D works on any drawing CADverter can open: DXF, SVG, PDF, Illustrator and HP-GL.
Can I extrude a DWG?
Not directly: no DWG reader can legally ship in a browser app. Save the DWG as DXF in AutoCAD or the free ODA File Converter, then drop the DXF here.