Porter Cable 3812 Manuel D'instructions page 18

Pay attention to grain direction. Make all cuts in the same direction as the grain whenever possible.
Always install the blade guard after the operation is complete.
ACCESSORY DADO HEAD
The blade guard and splitter assembly cannot be used when dadoing or moulding. It must be removed
or moved to the rear of the saw.
Use auxiliary jigs, fixtures, push sticks, and feather boards with this operation.
1. Dadoing is cutting a rabbet or wide groove into the workpiece. Most dado head sets are made up of two outside saws
and four or five inside cutters (Fig. 40). You can use various combinations of saws and cutters to cut grooves from 1/8"
to 13/16" for use in shelving, making joints, tenoning, grooving, etc. The cutters are heavily swaged. Arrange them so
that this heavy portion falls in the gullets of the outside saws (Fig. 41). The saw and cutter overlap is shown in Fig. 42 -
(A) being the outside saw, (B) an inside cutter, and (C) a paper washer or washers, used as needed to control the exact
width of groove. The two outside saws cut a 1/4" groove. Position the teeth of the saws so that the raker on one saw is
beside the cutting teeth on the other saw.
2. Attach the dado head set (D) Fig. 43 to the saw arbor.
NOTE: DO NOT USE the outside arbor flange with the dado-head set. Tighten the arbor nut against the dado-head set body.
Do not lose the outside arbor flange. It will ne needed when re-attaching a blade to the arbor.
Use the accessory dado head-set table insert (E) FIG. 43 in place of the standard table insert.
3. Fig. 44 shows a typical dado operation using the miter gauge as a guide.
D
Never use the dado head in a bevel position.
Always install the blade guard after the operation is complete.
Fig. 40 Fig. 41
E
Fig. 43 Fig. 44
18
A B
C
Fig. 42