This is a fun book if you like building things. It documents the building of a machine that can cut wood to shape under the control of a computer.

It uses stepper motors to provided three axis control and a standard router is mounted on a carrier driven by the computer. The construction uses MDF and lots of bolts and a surprisingly small number of metal parts. Just about everything is off the shelf and you really only have to master the art of cutting and drilling wood to build the machine.

Sometimes the instructions might strike you as a little basic. There is a lot of time devoted to talking about drilling, cutting and assembling. So much that you might well have trouble seeing the overall plan of the machine you are building. If you have any woodworking or practical skills than you will probably want to skim over large chunks of the descriptions. There are lots of pictures of tools and parts of the machine in development. The book isn't a complete step-by-step guide to building a CNC more an outline of a project that you need to take hold of and implement yourself.

If you are an electronics enthusiast or a programmer than you might be disappointed by the "off the shelf" aspects of the design. Not only do you have to buy standard stepper motors rather than recover units from scrap disk drives say, but the motor drivers and computer interfaces are off the shelf modules. This does simplify things in that all you have to do is wire them up using screw terminals and it does make the project more accessible. However, if you do know how to build electronics then there is no reason why you couldn't construct your own drivers and interface. The same, off the shelf approach is applied to the CNC software which only makes an appearance at the end of the book. There is virtually no programming for you to do other than enter co-ordinates to the CNC application.

At the end of the day you have your CNC machine - what do you do with it? Well one answer would be to use it to build a better CNC machine - but that's the programmer in me talking.

If you like this sort of constructional project then the book is a fun read even if you never actually get around to starting to implement the project.