Jet JJP-8BT Operating Instructions And Parts Manual page 18

Check the accuracy of the test cut before
working on the finished product.
Precautions
A thickness planer is a precision wood-working
machine and should be used on quality lumber
only.
Do not plane dirty boards; dirt and small
stones are abrasive and will wear out the
blade.
Remove nails and staples. Use the planer to
cut wood only.
Avoid knots. Heavily cross-grained wood
makes knots hard. Knots can come lose and
jam the blade. Any article that encounters
planer blades may be forcibly ejected from the
planer creating a risk of injury.
Preparing the Work
A thickness planer works best when the
lumber has at least one flat surface. Use a
jointer to create a flat surface.
Twisted or severely warped boards can jam
the planer. Rip the lumber in half to reduce the
magnitude of the warp.
The work should be fed into the planer in the
same direction as the grain of the wood.
Sometimes the wood will change directions in
the middle of the board. In such cases, if
possible, cut the board in the middle so the
grain direction is correct.
Do not plane a board that is
less than 6" long. It is recommended that when
planing short boards you butt them end to end
to avoid kickback and reduce snipe.
Feeding the Work
The planer is supplied with planer blades mounted
in the cutterhead. Feed direction is left to right (see
Figure 12). The planer feed is automatic; it will vary
slightly depending on the type of wood.
Preparation:
Feed rate refers to the rate at which the
lumber travels through the planer.
The operator is responsible for aligning the
work so it will feed properly.
Raise or lower the table to get the depth of cut
desired.
The surface that the planer produces will be
smoother if a shallower depth of cut is used.
Stand on the front side of the machine.
Boards longer than 24" should have additional
support from free standing material stands.
These can be purchased from JET – Stock #
709209. See sect. 15.0, Optional Accessories.
Planing
1. Position the workpiece with the face to be
planed on top.
Note: Feed direction is left to right (see
Figure 12).
2. Turn the planer on.
3. Rest the board end on the infeed side of the
table and direct the board into the planer.
4. Slide the workpiece into the infeed side of the
planer until the infeed roller begins to advance
the workpiece.
5. Let go of the workpiece and allow the
automatic feed to advance the workpiece.
6. Do not push or pull on the workpiece. Move to
the rear and receive the planed lumber by
grasping it in the same manner that it was fed.
To avoid the risk of injury due
to kickbacks, do not stand directly in line with
the front or rear of the planer.
7. Do not grasp any portion of the board that has
not gone past the infeed roller.
8. Repeat this operation on all of the boards that
need to be the same thickness.
Avoiding Snipe
Snipe refers to a depression at either end of the
board caused by an uneven force on the
cutterhead when the work is entering or leaving the
planer.
Snipe will occur when the boards are not supported
properly or when only one feed roller is in contact
with the work at the beginning or end of the cut.
Precautions for avoiding snipe:
Push the board up while feeding the work until
the outfeed roller starts advancing it.
Move to the rear and receive the planed board
by pushing it up when the infeed roller loses
contact with the board.
When planing more than one board of the
same thickness, butt the boards together to
avoid snipe.
Make shallow cuts. Snipe is more apparent
when deeper cuts are taken.
Feed the work in the direction of the grain.
Work fed against the grain will have chipped,
splintered edges.
18