Andy Rae: Snipe is most common in the thickness planer, and occurs when an unsupported end of the board, either at the front or at the back and usually about four inches long, lifts into the cutterhead during the cut. A small amount of wood is removed in these areas, leaving you with thinner wood at both ends of the board. The why goes like this: When you push the board into the planer, for a brief moment it's in contact with only the pressure feed roller in front of the cutterhead, at which time it can and often does tip upwards slightly due to the pressure from the roller, and thus into the knives. During exit, the same thing happens in reverse: The board is in contact with only the exit roller, and again the board is pressured up and into the cut. To counteract the pressure from the rollers and minimize snipe, I lever the far end of the board up slightly as its opposite end enters, then I walk around to the back of the planer and lift again as it exits. When planing multiple pieces, you can remove all snipe except for the start and end boards by feeding the workpieces end to end in a continuous run.