11
Palmgren Operating Manual & Parts List
84315
OPERATION (CONTINUED)
Such knives make it possible to scrape many interesting shapes
into the workpiece surface using one or two operations instead of
the many operations required with standard chisels. It is generally
not practical to use cutting methods with special shape tools.
Scraping methods should be used instead.
•
The holder should provide a shoulder against which the butt
end of the knife can be firmly seated.The knife must be secure-
ly mounted, either by means of a screw threaded into the hold-
er, or by compressing it between two prongs bolted together.
USING A BLOCK PLANE
Clear, glass-smooth finishes (especially on softwoods) can be
obtained by using a block plane set to take a fine shaving.
•
The tool rest should be raised up approximately to the top of the
workpiece – and the plane should be horizontal, but turned
slightly in the direction of travel so that it will take a shearing cut.
•
Two tool rests, one in front and the other behind the work, can
be used to advantage in positioning the plane so as to exactly
limit the depth of cut (and finished size of the workpiece).
USING WOOD RASPS AND FILES
•
A wood rasp will remove stock quickly when held against the
revolving workpiece. Care should be taken to support the rasp
firmly against the tool rest. An improperly held rasp, when used
on a rough surface, can kick back and cause operator injury.
•
The rasp will leave a very rough finish.
•
Finer finishes (similar to those produced by scraping) can be
obtained by using files in the same manner. Various types of
files can be used for shaping vees, beads, coves, etc. If pressed
too hard into the wood, some files can burn the workpiece.
•
Keep the file clean to keep it cutting uniformly. Files work best
on hardwoods.
HAND POSITIONS
When using any of the chisels, the hand takes a natural position on
the tool handle.This position may be near the middle of the handle
or towards the end, depending upon the amount of leverage
required. The position of the hand near the tool rest is a matter of
individual preference, but there are three generally accepted posi-
tions, each best for certain types of operations.
Roughing Off
Roughing off and other heavy work requires a firm grip and solid
positioning of the chisel against the rest. This is best obtained by
the tool-rest hand positioned illustrated. The wrist is dropped down
so that the heel of the hand below the little finger acts as a sliding
guide against the rest. The handle hand controls chisel position.
Finish Cutting
Finish cutting requires more control – with less force. Finish cutting
is better done with the palm of the tool rest hand turned up. The
wrist is still held down, and the side of the index finger acts as a
guide along the rest. In this position, control of the chisel is shared
by both hands. The fingers of the tool-rest hand are free to assist in
positioning the tool.
Intricate Cutting
Intricate, delicate cutting requires extreme control with practically
no force. This is best accomplished by guiding the chisel with the
fingers of the tool-rest hand. The hand is held palm up with the
wrist high. The little finger is placed against the rest to steady the
hand. The chisel does not touch the rest and the handle hand is
completely secondary to the tool-rest hand.
NOTE:
The first and second positions are equally good for scraping
operations, but the third position is practically never used for
scraping.
Cutting to Depth
Many scraping operations and cutting to depth with the parting
tool can be easily accomplished with the one hand. The chisel is
grasped firmly with the index finger on top to press it down
against the rest. It is thrust straight into the work. Holding the tool
in this manner leaves the other hand free to hold a pattern or
calipers, etc., to check work in progress.
Figure 32
Figure 33
Figure 34 – Using a Rasp
Figure 35 – Roughing
Figure 36 – Finish Cutting
Figure 37
Figure 38
