12
Palmgren Operating Manual & Parts List
84315
OPERATION (CONTINUED)
MAKING STANDARD CUTS
THE ROUGHING-OFF CUT
Reducing a square or odd shaped workpiece down to a cylinder of
approximate size for finish turning is called “roughing-off”.
Faceplate turnings and large diameter spindles should first be
partly reduced by sawing, but small spindles are easily turned
down entirely with the large (
3
/
4
″
) gouge.
•
Start the first cut about 2
″
from tail stock end – then run it
toward the tailstock and off the end of the workpiece.
•
Next, start another cut 2
″
nearer the headstock – and run it
back towards the tailstock, to merge with the first cut.
•
Continue cutting in this manner until 2 to 4
″
from the head-
stock is left uncut. Reverse the direction of tool travel and work
one or two cuts in succession toward the headstock and off this
end of the workpiece.
•
Never start a cut directly at the end – if the chisel catches the
end, it will damage the workpiece.
•
Never take long cuts while corners remain on the work, as this
tends to tear long slivers from the corners.
•
The first series of cuts should not be too deep. It is better to
partially reduce the work to a cylinder all along its length. After
that, start a second series of cuts to complete reducing it to a
cylinder.
•
Once a cylinder has been formed, step lathe up to next faster
speed. Further reductions in size can now be accomplished by
cutting as deeply as desired at any spot along the work. At this
stage, long cuts can be made from the center to either end.
•
Generally, roughing off is continued until the cylinder is
approximately
1
/
8
″
larger than the desired finished size.
•
Roundness can be tested by laying the gouge on top of the
work – it will not ride up and down when cylinder is perfectly
round.
ROUGH-CUTTING TO SIZE
The roughing-off cut can be made to accurately size the cylinder
to a given diameter.
Another method is to make a number of sizing cuts at intervals
along the work, then use the gouge to reduce the whole cylinder
down to the diameter indicated by these cuts.
MAKING SIZING CUTS
Sizing cuts are useful to establish approximate finished size diame-
ters at various points along a workpiece. The work can then be
turned down to the diameters indicated and be ready for finishing.
•
Diameters for sizing cuts should be planned to be about
1
/
8
″
greater than the desired finish diameters. A sizing cut is made
with the parting tool.
•
Hold the tool in one hand, and use the other hand to hold an
outside caliper preset to the desired sizing-cut diameter.
•
As the cut nears completion, lower the chisel point more and
more into a scraping position.
•
When the calipers slip over the workpiece at the bottom of the
groove, then the cut is finished.
SMOOTHING A CYLINDER
The final
1
/
8
″
can be removed in two ways. Either use the 1
″
skew,
working from the center toward both ends and taking lighter and
lighter cuts until finished, or use a block plane as illustrated in
Figure 29.
CUTTING A SHOULDER
A shoulder can be the side of a square portion left in the work-
piece, the side of a turned section, or the end of the workpiece.
Most shoulders are perpendicular to the work axis, but a shoulder
can be at any angle.
•
First, mark position of the shoulder with a pencil held to the
revolving workpiece.
•
Second, make a sizing cut with the parting tool, placing this cut
about
1
/
16
″
outside the shoulder position and cutting to within
about
1
/
8
″
of the depth desired for the area outside of the shoulder.
•
If shoulder is shallow, the toe of the skew can be used to make
the sizing cut. Do not go in deeper than
1
/
8
″
with the skew un-
less wider and wider vees are cut to provide clearance for this tool.
•
Use the gouge to remove any waste stock outside of shoulder.
Smooth this section, up to within
1
/
8
″
of shoulder, in the usual
manner. Finishing of the shoulder, unless it is more than 1
″
high, is best done with the
1
/
2
″
skew.
•
The toe of the skew is used to remove the shavings from the
side of the shoulder – down to finished size.
•
Hold skew so the bottom edge of bevel next to the shoulder
will be very nearly parallel to side of shoulder – but with cut-
ting edge turned away at the top so that only the extreme toe
will do the cutting. If cutting edge is flat against shoulder, the
chisel will run.
Figure 39
Figure 41
Figure 40
First Cuts
Testing Roundness
Figure 42
