A CNC router machine is probably the most useful tool a hobbyist can own, but the price for a CNC machine on the market is way more than the average hobbyist is willing to spend. You can build your own CNC with very basic tools, little knowledge of machinery, mechanics, or electronics, but be warned, these machines are inherently dangerous, so wear the proper protection and use common sense. At the very least, read the instructions and precautions on every tool you use.
Now, a CNC stands for Computer Numerical Control, but that is gibberish. It does hint you to the fact that something is controlled, and probably by a computer. It's really a mechanism that interfaces to a computer to control its movements, similar to a robot, but this machine has a specific function. It cuts or shapes things with this control. In essence, a computer precisely controls a cutting tool, like a router for instance, to cut materials such as wood, plastic or metals into shapes only bounded by your imagination.
This video tutorial will show you how to install a heat sink for a CNC router. Yes, you've use heat shrink, but now it's time for a heat sink. No, it's not a hot tub. A heat sink is usually a piece of metal that allows something that gets hot to discipate the heat. It is advised for the three driver chips on the HobbyCNC board. The installation is straight forward. Holes are marked and then drilled. It is important to note that the drill will create many metal shavings. Metal shavings are incompatible to the proper functioning of the driver board. If any of those shavings get on the board, you will risk a blown chip. Before final installation of the heat sink, a white compound should be spread between the component and the metal, like a peanut butter sandwich.
You will also see the insertion of the motor wires into the driver. Very important: the motor wires must be connected while there is no power to the board at all.