With that method, founded on a stack of adjustable grooving cutters rather than on a single saw blade, seven cutters enable for a wooden height of 70 mm to be machined in one shot and far over with two passes as described in that paper. The four sides of a box may be shaped without adjustment under condition of sitting two sides on a spacer the same depth than a finger. But forming two sides after two others works well too related to the accuracy of spindle lifting mechanism. In fact the technique is all about precisely piling the stack of adjustable grooving cutters and chippers.

You may read about virtual spindles here and that finger joint technique gives an instance of the use. After sitting the virtual shaft on its wooden base, I start piling a ring spacer as small as I can then follow a printed list detailing spacers and shims thickness as well as cutter parts location. That road sheet is really useful because the three parts of the grooving cutter drawn below are not commutables. It is worth developing and taking care of such material.

It remains to hand over the stack from its base to the spindle moulder shaft then I leave the whole pile gliding along the spindle and finally replace the virtual shaft before locking the cutter pile.

Here is the outcome and you may take a look at the virtual shaft location in the left hand side.