A stop block provides the most accurate and efficient way to crosscut multiple workpieces to the same length on a miter saw. For safety, the “keeper” section of the workpiece is normally held firmly against the stop block and fence, with the “offcut” unrestricted on the opposite side of the blade. However, it’s unsafe to cut short multiples this way because a grip on the keeper piece places your hand dangerously close to the blade.
The solution is to use a stop block and spacer on what would normally be the “off-cut” side of the blade, as shown in the drawing. Set up the cut with a spacer stick placed between the workpiece and the properly positioned stop block. Before making each cut, simply remove the spacer stick while holding the workpiece firmly against the saw fence opposite the keeper piece. This will prevent the “offcut” (which, in this case is actually your keeper piece) from pinching between the blade and the stop block during the cut, which can cause it to be violently thrown. This technique works quite well on a miter saw, and even on a radial arm saw, or a table saw crosscut sled.
– Bob Howard