It is damn thorough, providing step-by-step instructions on how to make a variety of different designs, including a robotic hand: ...

Ok, let's get started designing a robotic hand in order to learn some 2D CNC design techniques. Sure we could have made something boring like an acrylic computer case, but let's face it, fake ...

At this point, if you want to learn more about how it actually works, or if you want to make your own robot arm, you should read the creator's complete tutorial.