Guides
Longer write-ups on getting a drawing from the screen onto a machine: why a part comes out the wrong size, what a cutting service actually needs in the file, and how to fix the DXF or SVG that another program refuses to read. Newest first.
Are the Sydney Opera House shells really cut from one sphere? I checked with LiDAR
I traced the Opera House roof in FlatCad from open map data, then fitted spheres to a NSW LiDAR scan. The two biggest shells fit 75.17 m and 74.47 m.
Choosing between SVG, DXF and PDF for laser cutting and CNC
Each format stores curves, units and text in its own way. Here is what survives converting from one to another, and what to look at before you cut.
Should you print from STL or 3MF? What each file keeps and loses
An STL is only triangles, with no units or colours; a 3MF carries both. Why inch files print 25.4 times too small, and the mesh errors slicers flag.
Designing a print-in-place gear bearing that actually turns
A 66 mm planetary bearing designed to print in one piece: why 18, 12 and 42 teeth with a 25° pressure angle, and why 0.8 mm backlash is a 0.31 mm gap.
A print-in-place cryptex: how the lock works, and the numbers behind it
How a 5-ring print-in-place cryptex locks, with every clearance in millimetres, a geometric lock test run before printing, and the weak points to watch.
How to measure laser kerf and offset parts so they fit
Kerf is the width the beam or bit removes. Measure it to 0.01 mm with a 10-piece gauge, then size slots and finger joints so they press-fit.
From a 2D floor plan to a 3D house you can walk through
Two houses taken from a FlatCad 2D plan to a rendered 3D model: drawing the plan for 3D, wall and opening sizes, storeys, and how the walk-through works.
Why DXF and SVG files import at the wrong size, and how to tell which mistake it was
Why DXF and SVG parts arrive 25.4, 3.78 or 1.333 times too big or small: $INSUNITS, 72 vs 96 ppi, px vs mm. Diagnose it from one known dimension.
Tool pages
Each free tool also has its own page with instructions next to it. The ones people use most:
- SVG to DXF, Illustrator to DXF and PDF to DXF for moving vector artwork into CAD and CAM software with real arcs.
- Kerf offset and the laser test card for parts that have to fit.
- Box, drawer, living hinge and gear generators.
- Floor plans to scale, printed at 1:50 or 1:100.
- FlatCad 3D for parts to 3D print, with STL viewing and conversion.
The full list is on the free tools page, and every button in the 2D editor is explained in the manual. Something missing or wrong in a guide? Tell us.