Being able to quickly plane boards flat, smooth and to the exact thickness you need makes the thickness planer one of the most important machines in any workshop’s power tool arsenal. But a planer is only useful if it’s kept in good running condition. Some of the regular maintenance tasks you need to do include cleaning and lubricating the planer’s bed and running gear, keeping its knives sharp, and adjusting its extension tables, depth stop and cutting thickness scale.
Set the Depth Stops and Thickness Scale
Every planer has a scale and cursor to show just how thick a board will be after planing. But if the cursor setting is off, then you run the chance of ending up with stock that’s too thick or thin. Many modern portable planers also have a depth stop feature that allows you to easily and accurately set the cut thickness to one of several common sizes: 1/2", 3/4", etc. To check the accuracy of the stop mechanism, set it to one of the middle settings, say 3/4 of an inch, and then plane a board. Use a dial caliper to check the board’s thickness. If it’s greater or less than 3/4", read just the stop’s depth rod. Recheck the stop’s accuracy as before, and tweak it as needed until it’s dead-on.
Now, without changing the planer’s depth of cut, reset the planer’s cursor to read the same thickness on the scale as your planed board (in this case, 3/4"). It’s especially important to check and reset the cursor after changing knives, especially if your planer has older style knives that lack registration pins in the cutterhead.