Adjustments; Coplanar Alignment - Jet JJP-12 Operating Instructions And Parts Manual

Adjustments

Table and Knife Adjustments
For accurate jointing, at least three things must be
true:
1. Infeed and outfeed tables must be coplanar.
2. Knives or knife inserts must be set in the
cutterhead so that the highest point of their arc
is level with the outfeed table.
3. On the standard cutterhead, knives must be
parallel with the outfeed table across the entire
length of the knives.
These alignments are explained below.
Disconnect
power source before making any adjustments.
Failure to comply may cause serious injury.

Coplanar Alignment

Definition of coplanar
When the infeed table is set to the same level as
the outfeed table and together both tables form a
"perfect" flat surface, the tables are said to be
coplanar.
For optimum performance of the jointer, the infeed
and outfeed tables must be coplanar. If they are
not, the finished workpiece may have a slight taper
or twist across jointed its width or length.
Determining if tables are coplanar
The tables have been set coplanar at the factory,
but they should be double-checked by the
operator. Also, as the machine undergoes use, the
tables should be checked occasionally and
adjusted if necessary.
The procedure described below uses a steel
straight edge to set the tables, which should be
accurate enough for most purposes.
Important: The tables must be locked in position
when performing the following test.
Referring to Figures 8 and 9:
1. Disconnect jointer from power source.
2. Loosen the lock knob (A) and slide the
cutterhead guard (B, C) to clear the table.
3. Slide the fence assembly back (H, E) as far as
it will go, or remove it from the machine
entirely.
4. Rotate the cutterhead
interference.
machine from
5. Place a straight edge (D) across the front of the
6. Raise the infeed table (G) until it contacts the
The straight edge should lie level across both
tables. Move the straight edge to the back of the
outfeed table as shown in Figure 7 and perform the
same test.
If the straight edge does not lie level, the front or
back of one of the tables must be adjusted to make
the tables coplanar. Proceed as described in
to avoid knife
Performing the Coplanar Alignment (following
page).
12
Figure 8
Figure 9
outfeed table (F) and extending over the infeed
table (G). Note the position of the infeed table
(G). Note the position of the straight edge in
Figure 6 with respect to the fence (H).
straight edge (D).