Calibrating the Sight Gauge
The horizontal position gauge (also called the sight gauge) is used for aligning Domino tenons to a pencil mark on the workpiece. If the gauge is not perfectly centered over the mortising slot, the two workpieces will not be aligned when the joint is assembled.
Calibration Procedure
1.Take two pieces of scrap wood, and draw a thin line on each piece where a tenon is to be placed. You do not need to be concerned with how the edges line up.
4.Join the two pieces of wood together without glue, and examine the alignment of the original pencil lines.
5.If the pencil lines are not aligned, loosen the two screws on the sight gauge and slide the gauge sideways as noted in the upper image.
Note: The distance between the lines is twice the actual error. When adjusting the sight gauge, move it only 1/2 the distance between the lines.
Move Sight
Gauge Left
Alignment
OK
Fine Line
Sight Gauge
Center Line 
2. Set the mortise slot width to the narrow setting (page 8).
3. With the middle line of the sight gauge lined up on the
pencil line, plunge a mortise slot into each piece of wood. (Do not use the stop pins.)
Screws
Move Sight
Gauge Right
20 | Domino XL DF700 |