How wood planers work
As most everyone knows, a 2 x 4 is not two inches by four inches, it is about 1 ¾ x 3 ½ inches. They were not always this way; a century ago they actually were 2” x 4”. When boards are first cut from a log, they are rough sawn; years ago if you wanted a smooth surface on the wood the carpenter used hand wood planers. As the woodworking industry became more modern and mechanized, mechanical devices were developed, one of which was a power planer. With the advent powered woodworking planers, the mill was now in a position to prepare fully finished lumber for use in construction. But as the rough cut boards were 2” x 4”, after they were planed, they obviously became smaller.
Powered woodworking planers are now a must in every woodworking shop, most certainly industrial shops and in many cases, even home craftsmen have one.
Basically, a planer is simply a tool that makes the sides of a wooden board flat and the board a specified thickness. There are handheld wood planers that are more designed for the hobbyist, the industrial version is somewhat different, it is called a thickness planer and they are manufactured in a host of different sizes in terms of board length, board thickness and power.
Smaller machines are fed by hand whereas the larger designs drive the board through the planer with a powered roller. Regardless of how the board gets through the machine, as it passes through, the board is surfaced with a very sharp, rotating cutter blade. The larger the machine, the larger the board can be. Once the board comes out the other side, the surface is smooth and parallel with the opposite side. All of this is well if the opposite side is acceptable, if it is not and both sides must be finished, the board is turned over and fed through again.
Although the powered woodworking planers are most often used to make boards smooth, flat and with parallel surfaces, it is possible to prepare the board in different manners. The cutter of a powered planer consists of blades which are held in position in a mandrel, as the cutter rotates at high speed, the board is treated. If the contours of the blades are nothing other than a flat surface, then of course the finished board will be flat. There are also planer blades which can create different effects on the wood surface; uneven, distressed and antiqued surfaces are commonly creations for the furniture industry.