Powermatic 3520C, Operating Instructions And Parts Manual

 18

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. 

Figure 10-3  

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. 

Figure 10-4 

8. Advance the tailstock spindle with 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.