3D-modeling tools help turn individual ideas into beautiful models and prototypes for a variety of fields. These Free tools allow building and customising models from the ground up.
Thingiverse
Thingiverse Education provides over a hundred free lessons that make teaching with a 3D printer easier and more effective for a variety of grade levels and subjects. It also provides a community where educators can exchange best practices or remix projects. With nearly a half-million 3D models available to print for free, Thingiverse is the biggest online repository for 3D printable content.
Difficulty: Easy Type: Customize, remix and inspire
Platforms: Web Cost: Free
http://www.thingiverse.com/education
PrintShop
Create 3D models from your own drawings or use easy tools to customize bracelets, medals, and signs, right from your iPad
Difficulty: Easy Type: Tap and drag
Platforms: iPad Cost: Free
https://itunes.apple.com/us/app/makerbot-printshop/id884304128?mt=8
Tinkercad
Construct 3D designs from simple shapes and combine, move, resize, and manipulate them using your mouse.
Difficulty: Easy Type: Drag and drop, solid modeling
Platforms: Web Cost: Free
https://www.tinkercad.com/
Sculptris
Use your mouse to sculpt life-like characters and other organic shapes from a virtual
ball of clay.
Difficulty: Intermediate Type: Digital Sculpting
Platforms: Mac, Windows Cost: Free
http://pixologic.com/sculptris/
OpenSCAD
Write simple code to generate 3D printable designs that can include geometric objects, text, and modifiable dimensions.
Difficulty: Intermediate Type: Design with code
Platforms: Mac, Windows, Linux, Web Cost: Free
http://www.openscad.org/
Blender
Blender is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing and motion tracking, even video editing and game creation.
Difficulty: Advanced Type: Modelling, animation, sculpting
Platforms: Windows, Mac, Linux Cost: Free
https://www.blender.org/
Clara.io
Clara.io is a full-featured cloud-based 3D modeling, animation and rendering software tool that runs in your web browser. With Clara.io you can make complex 3D models, create beautiful photorealistic renderings, and share them without installing any software programs.
Difficulty: Intermediate Type: Modelling, animation, sculpting
Platforms: Web Cost: Free
https://clara.io
SketchUp
SketchUp is synonymous with friendly and easy to use 3D modeling software. One of their plus point is that they don’t sacrifice usability for the sake of functionality. You can start by drawing lines and shapes. Push and pull surfaces to turn them into 3D forms. Stretch, copy, rotate and paint to make anything you like.
Difficulty: Easy Type: Drag and Drop, Modelling, sculpting
Platforms: Web Cost: Free
https://www.sketchup.com/
Image courtesy – Thingiverse