Page 43 - Router Boss Manual

With the stop positioned, we’ll use it to position
the bit to cut the other cheek of the tenon. Loosen the
router plate locking knob and slide the plate away from Gauge bars
the stop far enough to insert gauge bars. In our case,
we’re using a 3/8” diameter bit so a 3/8” gauge bar
plus a 1/4” bar for the thickness of the tenon (to match
our mortise) should position the bit correctly to cut the Precision stop
other cheek. You can use one of the green router plate
stops with the knob and a 1/4” oval nut (supplied with Router plate stop
your machine) to act as a stop for this setting. Finally, Router stop rod with oval nut
retighten the router plate locking knob.

Move the stock clear of the bit, turn the router on
and turn the power feed crank so as to cut the front
tenon cheek. Check the fit of the tenon in the mortise,
making sure the tenon fits snugly, but also that the faces
of the rail and stile pieces are flush. If you need to make
minor adjustments, turn the precision stop’s adjusting
barrel in or out to put the tenon cheek further or closer
to the edge respectively. If you move this stop, you’ll
need to reset the other stop by using the gauge bars as
you did before.

When you’ve got the tenon fit fine-tuned, you’ll
need to cut a “haunch” so the tenon will nest in the
groove on the stile. Measure the distance that the mor-
tise is inset from the end of the stile and mark the end
of the tenon. We need to raise the bit by 1/4”, so insert
a 1/4” gauge bar below the depth stop to raise the bit,
loosen the router plate locking knob and cut up to the
line you marked. To cut the tenon on the opposite end
of the rails, cartwheel the workpiece end for end so the
same face is against the machine. Then use the stops
you set previously to repeat the tenon cuts.

Haunch fills and
Haunch hides the groove

Since all the glue strength is in long grain to long grain
(tenon cheeks), and not in the end grain of the stile, it’s OK to
eyeball the haunch cut and make it slightly oversized.
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