Spindle Turning; Stock Selection - Powermatic 3520C Instrucciones De Funcionamiento Y Manual De Piezas

For best results, use a slow speed grinder (1800
rpm) fitted with a 60-grit aluminum oxide wheel (for
shaping) and a 100-grit alum. oxide wheel (for final
sharpening and touchup). The grinder should be
located near your lathe and at a comfortable height.
A diamond dresser will keep the wheels true and
eliminate glazing.
Never allow the tool to rest in one place on the
wheel; keep it moving and use a light touch.
Carbon steel tools can overheat easily and should
be cooled frequently. If the edge turns blue, it has
lost its temper and should be ground past the blue
area. High-speed steel tools are not as likely to
overheat, but can be damaged if allowed to get red
hot. High-speed steel tools should not be quenched
for cooling. Honing with a diamond lap or slipstone
will save trips to the grinder and keep the edge
fresh.

10.3 Spindle turning

Spindle turning takes place between the centers of
the lathe. It requires a spur or drive center in the
headstock and a live or dead center in the tailstock.
A cup center rather than a cone center in the
tailstock will often reduce the risk of splitting the
stock.
Figure 10-2 shows the basic profile shapes in
spindle turning.
Figure 10-2

10.3.1 Stock selection

Stock for spindles should be straight grained and
free of checks, cracks, knots and other defects. It
should be cut 1/8" to 1/4" larger than the finished
diameter and may require additional length so the
ends can be removed later. Larger stock should
have the corners removed to produce an octagon
making the piece easier to rough down to a cylinder.
1. With a combination square, or plastic center
finder for round stock, locate and mark center
on each end of the workpiece. Accuracy is not
critical on full rounds but extremely important on
stock where square sections are to remain. Put
a dimple in the stock with an awl or nail, or use
a spring-loaded automatic center punch.
2. Extremely hard woods may require kerfs cut
into the ends of the stock (Figure 10-3) using a
band saw, so the wood will accept the spur
center and the live center.
3. Drive the spur center about 1/4" into the
workpiece, using a wood mallet or dead blow
hammer as shown in Figure 10-4. Be careful
that you do not split the workpiece. Never use
a steel face hammer and never drive the
workpiece onto the spur center while it is
mounted in the Lathe spindle.
4. Make sure the headstock is locked to the Lathe
bed.
5. Clean the tapered end of the spur center and
the inside of the headstock spindle.
6. Insert the tapered end of the spur center (with
the attached workpiece) into the headstock
spindle.
7. Support the workpiece while bringing the
tailstock into position about 1" away from the
end of the workpiece. Lock the tailstock to the
bed.
8. Advance the
handwheel in order to seat the live center into
the workpiece. Use enough pressure to secure
the workpiece between the centers so that it
won't fly off, but do not use excessive pressure.
9. Tighten the spindle locking handle.
18
Figure 10-3
Figure 10-4
tailstock spindle with the