-16-
Figure 35. Tailstock offset adjustments.
Scale
Left Side
Jack Screw
Centers
Dead Centers
The dead center achieves more accurate results than
a live center, but it requires low spindle speeds and
a small amount of oil to reduce friction heat that may
damage the workpiece.
Use the HSS dead center in the spindle, where the
workpiece does not rotate on the tip and does not
generate friction.
Use the carbide-tipped dead center in the tailstock
where the workpiece will rotate against it and
generate friction. The carbide-tipped dead center can
better withstand the effects of friction; however, the tip
of the center must be lubricated to avoid premature
wear and maximize smooth operation. Also, using
low spindle speeds will also reduce the heat and wear
from friction.
Live Centers
A live center has bearings that allow the center tip and
the workpiece to rotate together, and can be installed
in the spindle and the tailstock quill for higher speeds,
but with a slight bit of accuracy loss.
Mounting Dead Center in Spindle
1. Disconnect Lathe from POWER !
2. Thoroughly clean and dry the tapered mating
surfaces of the spindle bore, tapered sleeve, and
the center.
3. Insert the center into the sleeve, then insert the
sleeve into the spindle bore through the chuck or
faceplate.
Removing Center from Spindle
To remove the sleeve and center from the spindle,
insert a piece of round bar stock or similar tool through
the outboard end (on the left side of the headstock),
then tap the sleeve loose.
Mounting Center in Tailstock
Either a dead center or live center can be mounted
in the tailstock. Mounting instructions are the same
for both.
Figure 36. Jack screw adjustment verses
tailstock movement.
Figure 37. Example of using a dead
center installed in the tailstock.
2. When the offset is achieved, snug the jack screws
so the tailstock position is locked.
To mount a center in the tailstock :
1. Disconnect Lathe from POWER !
2. Thoroughly clean and dry the tapered mating
surfaces of the tailstock quill bore and the carbide-
tipped dead center.
3. Use the tailstock quill handwheel to feed the quill
out from the casting about 25mm.
4. Insert the center into the tailstock quill.
5. Seat the center
fi
rmly into the quill during
workpiece installation by rotating the quill
handwheel clockwise to apply pressure.
Removing Center from Tailstock
To remove the center from the quill, hold onto it with a
rag in one hand, then rotate the tailstock handwheel
counterclockwise to draw the quill back into the
casting until the center released.
