Snipe is that annoying way in which a planer cuts a little deeper on the first and/or last few inches of a board. The reason for snipe is very simple. When the board is only being pressed down by one of the two rollers, one of the ends of the board is lifted off the bed of the planer. The illustrations below show how this occurs. In Figure 1, the board (which is moving from left to right) is no longer being pressed down by the first roller, so the back end rises and contacts the cutterhead. Figure 2 shows the situation when the board is first fed into the planer: Until it contacts the second roller, the front end is up off the planer bed and making too much contact with the knives.

While these drawings are a bit dramatic, they do show the concept rather well.

A lot of planer manufacturers have tackled this problem, and a few have come up with solutions that partly solve the dilemma. The latest trick is to have the four cornerposts of the machine work in a united fashion. It works for a while, and then you have to start making adjustments.

We have used an old shop trick on our planers here at Woodezine for several years. We added a longer bed - an MDF insert - to each machine. The theory is that the factory bed is very short, so a longer bed might give boards less chance to "lean" - to rise up into the cutterhead. It works rather well to reduce snipe, but falls far short of eliminating it.

There is really only one way to guarantee that you won't get snipe. That is to attach some scrap (the same thickness as your board) to either side of the workpiece. The scrap pieces should be at least a foot longer than the board (6" on each end). Hot melt glue works, or you can even just hold them together as you feed the workpiece to the knives.

At right, we see a Delta planer equipped with an MDF bed extension, running a piece of Spanish cedar which is flanked by a couple of scraps of aspen.

Note: Don't use mechanical (metal) fasteners such as finish nails or screws to attach the scraps: if they hit the knives, it could be both expensive and potentially dangerous.