This is arguably the most critical step in matching your sander to the shaped board
Run a board through the shaper(s); check for profile accuracy by placing the template on the wood and hold up to a light (figure 1). No light between the wood and the template
should be seen if profile is correct. If the shape is incorrect, have the knives corrected, do not attempt to sand.
If knives are correct, run a board through the shaper(s), wait until the shaper heads have stopped rotating. Using a soft #2 carpenter’s pencil, evenly mark the profiled board
3 or 4 places from top to bottom of profile (figure 2). It is important to hold the pencil correctly. The correct orientation of the pencil is to have the flat side facing up.
Holding the pencil this way will prevent indenting the board by pressing the narrow side of the pencil into it. When this happens, there will be a tendency to over-sand the board,
resulting in premature wearing of strips.
Start the sander(s) and the feed. After the board exits the machine, check the pencil lines on the board. If sander(s) is properly aligned, the pencil lines should be sanded
lightly over the width of the profile, but should not be completely removed. The goal is to sand the entire profile, while leaving some of the pencil mark.
If there are areas where the line is unchanged or the wood is not sanded or if the line is completely removed, further adjustment of the sander head is necessary.
After correcting adjustment, run a few more boards to ensure that the setup is correct.