CAD for 3D printing: what to design in and what to export
CAD is computer-aided design, that is software for creating precise 2D and 3D models. A model from CAD is exported to STL or 3MF and sent to print.
No model? No problem, pick a ready one
These sites have thousands of free models. Download an STL or 3MF and upload it here. If you sell it or use it for business, check the model licence. How to pick a model and licence
What CAD is
The abbreviation CAD stands for computer-aided design. In 3D printing it means programs where you draw a part with exact dimensions, holes and tolerances. Other options are digital sculpting for organic shapes and parametric modelling for parts you need to change later.
The difference from sculpting programs is that CAD works with exact dimensions in millimetres, while sculpting shapes a surface freely.
Programs you can try
What to export
Export STL or 3MF from CAD, in millimetres. For multicolour printing use 3MF with colours assigned. We also accept STEP, which carries exact surfaces and is converted to a mesh before printing. The file can be up to 50 MB.
The largest part we can print in one go is 246 × 246 × 256 mm. Bigger things have to be split, see splitting a model.
What to think about when designing for print
- Design with the wall thickness for a 0.4 mm nozzle in mind.
- Allow for tolerances on parts that fit together.
- Chamfer the bottom edges and fillet the inside corners.
- Limit overhangs beyond 45 degrees.
Common questions
What should I start with?
For simple parts, Tinkercad in your browser. For precise, editable models, a program such as Fusion, Onshape or FreeCAD.
Which format should I send from CAD?
STL or 3MF in millimetres. 3MF if you want several colours. We accept STEP too.
What if I need to change the part later?
Keep the original CAD file. You can change a dimension quickly and export the model again.
Related terms
Parametric modelling
Parametric modelling is a way of designing where the shape is defined by dimensions and rules, so you change it by editing a number instead of redrawing.
Digital sculpting
Digital sculpting is shaping a 3D model much like clay. It suits characters, animals and organic shapes that would be hard to draw in CAD.
STL
STL is the most common file format for 3D printing. It describes only the surface of a model as a mesh of triangles, with no colours, material or units.
3MF
3MF is a 3D printing file format that carries units, colours, materials and several parts as well as the shape of the model. It succeeds STL and is the best choice for multicolour printing.
STEP
STEP is the standard format for exchanging 3D models between CAD programs, defined by ISO 10303. Unlike STL it describes exact geometry with curves and surfaces, not a mesh of triangles.
Tinkercad
Tinkercad is a free 3D editor that runs in your browser and builds models from basic shapes. It suits simple parts, stands, boxes or lettering, not complex shapes.
SourcesSources checked 1 November 2026, 1
- Computer-aided design, Wikipedia, checked 2026-11-01
We will print it for you
Upload a model and see the price per piece, the total with shipping and the date at once. We print in Košice, Slovakia, from PLA and PETG.
No model? No problem, pick a ready one
These sites have thousands of free models. Download an STL or 3MF and upload it here. If you sell it or use it for business, check the model licence. How to pick a model and licence