Most of everything around you likely started as a 3D model in the computer of some professional engineer, architect, industrial designer, or inventors, and was built with expensive Computer Aided Design (CAD) software. Generating 3D models is a fundamental first step in 3DPrinting. Using CAD, you can generate precisely dimensioned products, parts, trinkets, and anything you need. 3D Modeling is different from CAD, in that 3D modeling is kind of like digital sculpting with clay; it's great for creating characters, animations, textures, and otherwise organic shapes. However, when it comes to creating a replacement knob, or bracket for a table CAD is usually the go-to tool.
Here are some CAD resources that are free and run in the browser:
- 3D Orchard is a free platform for crowdsourced design. The CAD is free, fully-featured, and built into the browser.
- Tinkercad is a basic CAD that uses drag/drop blocks and primitive shapes.