Convert, Repair & Prepare
Engineering Files

Diagnosis-first mesh repair with a full defect report.

See what is actually wrong before anything changes: open edges, non-manifold geometry, flipped normals, duplicates, debris — with before/after dimensions and volume. Check-only mode inspects without touching your file; repair mode delivers a watertight STL and shows every step it took.

Convert mesh to editable CAD geometry, with analytic reconstruction for mechanical parts.

STL files are triangles approximating a shape; STEP files are mathematical surfaces CAD software can actually edit. Simple prismatic parts come back with true planes and cylinders you can re-dimension (checked against the mesh, never guessed); everything else gets a clean faceted solid. Works best on brackets, enclosures, mounts, and machined shapes.

Material, mass, cost, and time from mesh volume.

A shell-plus-infill model turns the enclosed volume into grams, dollars, and hours, with presets for PLA, PETG, ABS, TPU, Nylon, and resin, and your own filament price. Every assumption is printed in the report. An estimate for planning, never a quote.

Wall thickness and overhang analysis before you print.

Rays are cast into the solid to measure wall thickness across the surface, and every face is checked against your support angle. You set the process limits; the report shows the thinnest walls, the unsupported area, and a verdict. Analysis only — your file is not modified.

Find the orientation that needs the least support.

Tries every stable resting face of your part, ranks the candidates by unsupported area, bed contact, and height, and returns the STL already rotated into the winner. The full ranking streams to the console so you can overrule it.

Quadric decimation to cut triangle count and file size.

Shrink a heavy STL or OBJ so it slices and loads faster, by a percentage or to a target triangle count. Flat areas thin out first, curved detail is kept, and a watertight mesh stays watertight — with before/after triangle count, file size, and volume drift shown.

Tessellate CAD geometry to a triangle mesh for 3D printing.

Got a CAD file from an engineer or downloaded a model from GrabCAD? Slicers like Bambu Studio, PrusaSlicer, and Cura only accept mesh formats. Drop your STEP file in and get a print-ready STL back. You control the mesh resolution — higher detail for small parts, lower for large prints where file size matters.

STL vs STEP

Full format comparison — when to use each, what they store, and how they differ.

The most common source of confusion in 3D workflows. Explains what each format actually stores, why you can't just rename the file extension, and when each format is the right choice.

STEP vs STL for Manufacturing

What to send a machine shop, and why an STL slows down your quote.

What a CNC shop does with your file, what an STL throws away that matters for quoting and machining, how tolerances and GD&T fit in, and how to get a mesh back to a manufacturable STEP.

How to Convert CAD for 3D Printing

From a STEP solid to a clean printable STL, at the right resolution.

Why you convert through STEP, how the deflection setting trades smoothness against file size, choosing STL vs 3MF, and the unit and watertightness pitfalls that ruin a print.

How to Reduce STL File Size

Three ways to shrink a heavy STL, and how far you can push each.

Why STL files get huge, mesh decimation vs re-exporting from CAD vs switching format, how much you can safely reduce by source type, and the mistakes that cost you detail or a clean master.

How to Repair an STL File

Check first, then fix — the eight mesh defects and the tools that handle them.

What breaks STL files, how to diagnose each defect before repairing, where automatic repair can distort geometry, and downloadable broken test files to try any repair tool against.

STL Mesh Defects, Illustrated

Every common defect shown in the 3D viewer, next to its real check report.

Non-manifold edges, holes, flipped normals, debris shells, open surfaces and hairline cracks — what each one looks like, why it happens, and how repair handles it.

3D File Formats Explained

STL, STEP, OBJ, FBX, GLTF — what each format is designed for.

Covers what each format stores, what software opens it, and which to use for printing, CAD, game engines, and web viewers.

How Thick Should 3D Print Walls Be?

Real minimums by process, and how to measure the walls of an STL.

Why 0.8 mm is the FDM floor with a 0.4 mm nozzle, what resin and SLS tolerate, where thin walls sneak into models, and how to check a mesh before the printer finds the problem for you.

How Much Does a 3D Print Cost?

The material math with a worked example, and why quotes are 3–10x that.

From mesh volume to grams to dollars, what the material math leaves out (labour, failures, machine wear), and the levers that actually make a print cheaper.

Print Orientation Explained

The free lever that changes support, strength, finish, and time.

The 45° rule, why layer lines are the weak direction, when to overrule the least-support orientation, and how to rank every candidate automatically.

How to Convert STL to STEP

The hard direction, honestly: what converts well and what cannot.

What the conversion actually does (and does not recover), when a part comes back with true analytic planes and cylinders versus faceted curves, why organic shapes stay thousands of tiny faces, and the repair-first workflow that prevents most failed conversions.

How to Check if an STL Is Watertight

What watertight means precisely, and three ways to check in under a minute.

Boundary edges, non-manifold edges, and shells — how to read the numbers in a mesh report, and why watertight alone does not make a file printable.

3D Scan to Printable Model

Repair, then simplify, then print — or convert, with honest limits.

The full pipeline from noisy scanner output to a usable model: closing holes, dropping debris, decimating 90% of the triangles, and what scan-to-CAD can and cannot deliver.

OBJ vs STL

What you lose converting between them — and when it doesn't matter.

Color, textures, and UVs versus bare geometry: why OBJ→STL is safe for printing, why the reverse buys nothing, and the scale surprise that shrinks parts a thousandfold.

What STL Export Tolerance Should I Use?

The one export setting that matters, with values that work.

How deflection trades accuracy against file size, why 0.05–0.1 mm suits most printing, and the failure modes at both extremes — faceted holes and 400 MB brackets.

Fixing "Non-Manifold" Slicer Errors

What Cura and PrusaSlicer actually mean, and the two-minute fix.

Translates each slicer's wording, says when the warning is safely ignorable, and walks the check → repair → re-slice path with before/after numbers.

3MF vs STL

Should you switch? What 3MF fixes, and what keeps STL alive.

Units, compression, colors, and slicer projects versus universal acceptance — with converters both directions and a when-each-wins table.

Preparing an STL for CNC Machining

The shop asked for "a real model" and the STL is all you have.

Repair → convert to STEP → correct the nominals in CAD — including the skipped dimension check that scraps parts, and when remodeling beats converting.