Jointer Operations - Jet JJP-8BT Operating Instructions And Parts Manual

12.4 Jointer operations

Correct operating position
The operator must be positioned offset to the
infeed table (Figure 20).
Figure 20
Hand placement
Never pass hands directly over
the cutterhead.
Referring to Figure 21:
At the start of the cut, the left hand holds the
workpiece firmly against the infeed table and fence
while the right hand pushes the workpiece in a
smooth, even motion toward the cutterhead. After
the cut is under way, the new surface rests firmly
on the outfeed table. The left hand is transferred to
the outfeed side (Figure 21) and presses down on
this part of the workpiece, at the same time
maintaining flat contact with the fence. The right
hand presses the workpiece forward and before
the right hand reaches the cutterhead it should be
moved to the work on the outfeed table.
Surfacing
The purpose of surfacing on a jointer is to produce
one flat surface (Figure 21). The other side can
then be milled to precise, final dimensions on a
thickness planer resulting in a board that is smooth
and flat on both sides and each side parallel to the
other.
If the wood to be jointed is cupped or bowed,
place the concave side down, and take light
cuts until the surface is flat.
Never surface pieces shorter than 12 inches or
thinner than 3/8 inch without the use of a
special work holding fixture.
Never surface pieces thinner than 3 inches
without the use of a push block.
Cuts of approximately 1/16" or less at a time
are recommended, which provides for better
control over the material being surfaced. More
passes can then be made to reach the desired
depth.
Direction of Grain
Avoid feeding work into the jointer against the grain
(Figure 22). This may result in chipped and
splintered edges.
Feed with the grain to obtain a smooth surface, as
shown in Figure 23.
Edge Jointing
Jointing (or edging) is the process of creating a
finished, flat edge surface that is suitable for joinery
or finishing (Figure 24). It is also a necessary step
prior to ripping stock to width on a table saw.
Never edge a board that is less than 3 inches
wide, less than 1/4 inch thick, or 12 inches
long, without using a push block.
When edging wood wider than 3 inches lap the
fingers over the top of the wood, extending
them back over the fence such that they will
act as a stop for the hands in the event of a
kickback.
When workpiece is twice the
length of the jointer infeed or outfeed table use
an infeed or outfeed support.
16
Figure 21
Figure 22
Figure 23