A surface planer is a type of tool that can adjust the thickness of a board and make that surface completely flat, assuming the other side of the board is completely even already. This machine features a motor that rotates a cutting head at a high speed, and since the machine is quite large and heavy, it usually sits on a dedicated surface such as a plane bench or table. The size of the surface planer can vary, and the size of the boards that can be planed in the machine will vary according to the machine's size.
Planing a board using a surface planer starts with adjusting the machine so it cuts the board at the proper depth. This is done by adjusting the controls on the machine, which is usually a manual control or an electronic control for more accuracy. The surface planer can then be turned on if it has not been already, and the board can be fed into the opening on one side of the machine. The board will then be engaged by the in-feed roller, which will guide the board deeper into the machine toward the cutting head.
Once the board reaches the cutting head, the surface of the board will be planed, or essentially flattened evenly. As the board moves under the cutting head, the out-feed roller will come in contact with the board, further pulling it along through the surface planer until the entire board as been cut. The person operating the machine will need to support the board as it exits the machine to prevent it from falling and potentially causing damage to the board and to the machine.
One of the common problems associated with the surface planer is a condition called snipe. This occurs when the board is planed at a different thickness at the beginning or end of the planing process because of the board being fed into the machine incorrectly. It can be prevented by properly feeding the board into the machine and supporting it adequately as it leaves the machine, thereby providing a clean plane that is even all the way down the course of the board. Another common problem with a surface planer is the machine's inability to make a straight cut if the opposite side of the board is not even or very close to even. If the opposite side is not even, the planer will plane the board in accordance with any imperfections on the opposite side.