Utilising Leigh D4R to achieve repetitively same distances when building a drawer frame

We achieve the repetitively same distances by avoiding measuring and instead focusing on transferring the distance. How we transfer the distance does not matter that much and there are many good ways to transfer a distance to a set-up. The importance is that it is done in a way where we can easily see or feel if the wanted distance is achieved.

In the picture can be seen how this can be done on the Leigh. It was previously described how to route the mortise at the end, using the vertical wooden stop bit as a reference . In this picture is seen how the very same stop bit is still used as a reference, and as a reference to the very same end on the bit being routed. It is important to keep using the same end of the bit being routed as reference, so errors in measurements do not multiply. Every new measurement starts from the end. Thus, previous errors in measurements do not affect the next.

Previously, the inner side of the stop bit was used as a reference. In this routing setup, the outer side of the stop bit is used when setting up the piece to be routed.

This means that the thickness of the stop bit (④) has to be adjusted for. It can be done mathematically, subtracting the thickness before setting the stop, which works well if you are building from a drawing and using a sliding gauge with a built-in scale. However, that kind of calculation often leads to mistakes (adding instead of subtracting or making an error in the calculation). Thus, a good habit is to use another stop bit (⑤) with the same thickness as the stop bit to adjust the measurement. This is easy. First place one of the test pieces (③) at the intended final location of the piece to route (①). Then place another piece with the same thickness as the stop bit at the side of that (⑤). Now dial in the distance from edge (②) to that "simulated stop bit".