10.
Back the tool bit off and turn the lathe OFF.
11.
Loosen the arbor nut, rotate the drum 1⁄2 turn
(180°) on the arbor and inner adapter, and retighten the
nut.
12.
Turn the lathe ON.
13.
Turn the spindle feed handwheel 1⁄2 turn in
either direction and make a second scratch cut.
Figure 14 – Second scratch cut
14.
Turn the lathe OFF.
15.
Examine the scratch cuts.
If the first and second cuts are opposite one another
(180° apart), remove the drum from the arbor, check
the mounting adapters and arbor for nicks, burrs, or
chips, remount the drum, and repeat scratch cut
process.
If the scratches are side by side, proceed to step 16.
16.
Turn the spindle feed handwheel until the deep-
est worn groove of the drum lines up with the point of
the tool bit.
17.
Advance the tool bit into the bottom of the
groove by rotating the cross feed handwheel counter-
clockwise.
Note:
These operations may be done with the lathe
running.
The depth of cut dial will show the approximate
reconditioned diameter of the drum. This measure-
ment must be compared with:
A.
The maximum rebore limits cast into the drum.
B.
The measured diameter to determine the best
amount of material to be removed in one pass.
18.
Determine the depth-of-cut by these general
guidelines:
• Roughing cuts should be no deeper than 0.020".
• Finish cuts should be no shallower than 0.004"
deep.
19.
With the lathe running, set the depth-of-cut dial
to the depth desired and lock the cross feed by tight-
ening the lock knob.
20.
Set the spindle feed speed while the lathe is
running by unlocking the feed dial lock screw and turn-
ing the dial. Tighten the lock screw when speed is set.
The rough cut feed range is between 0.006" (0.15
mm) (6 on the dial) to 0.020" (0.50 mm) (20 on the dial).
The finish cut feed range is between 0.002" (0.05
mm) (2 on the dial) and 0.006" (0.15 mm) (6 on the
dial).
21.
Set the feed shut-off by sliding it on the shaft to
a point that approximately equals the depth of the
drum and tightening it in place. The feed will stop
when it reaches this point.
22.
Engage the feed lever to begin drum recondi-
tioning.
Snap-on • 13
Brake Lathes
Second
Scratch Cut