I recently purchased Toon Kit For Cycles from Cogumelo Softworks.This is my review of the product and a tutorial for how I use the shader network.
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Introduction: 00:04
Review: 01:04
Tutorial Easy Toon Shader: 04:03
Tutorial Simplify Normals Toon Shader: 11:10

Toon Kit For Cycles: http://cogumelosoftworks.com/index.php/toonkit/
Blender Market: https://www.blendermarket.com/products/toonkit-for-cycles
Eevee NPR Shaders: https://www.blendernation.com/2017/12/30/npr-for-eevee/
Blender Internal Render News: www.blendernation.com/2018/04/19/blender-internal-renderer-removed-from-2-8/

Here is one of my initial tests using the Vincent model: 

How to build Gears of different sizes in Blender 3D and have them work together.
 
Recently I completed a small modeling project where I needed to create some gears for a catapult. 
 
I’d like to share my method for creating, calculating and driving gears.
 
Please let me know if you have any questions in the comments below, or if there is a section of the video you want me to expand on. 

Below the the original file. This includes the three gears, the drivers and a short animation. ​

​Extra Objects Addon: https://tinyurl.com/y9grygqo
 
Gear Generator: http://geargenerator.com/
 
Gear Math In Detail: https://www.cs.cmu.edu/~rapidproto/mechanisms/chpt7.html