AMMCO 6950 Twin Cutter Tool - Manual (Page 2)

2 • 6950 Twin Cutter Tool
The 6950 Twin Cutter Tool mounts on the lathe in
place of the boring bar. It resurfaces both faces of
a brake rotor simultaneously. Each tool holder is
individually adjustable (in thousandths of an inch
or millimeters) to facilitate precise depth-of-cut
settings (Figure 1).
Figure 1 – Depth-of-cut adjustment knobs
Installation
1. Remove the nut and self-aligning washers
from the boring bar mount on the lathe.
2. Lift off the upper and lower clamp and
remove the boring bar (on models 4000 and
4100 only). Only the stud remains.
Figure 2 – Lathe set up for drum turning
3. Place the twin cutter on the stud.
4. Place the self-aligning washers on the stud,
followed by the nut. Hand tighten the nut.
Figure 3 – Remove boring bar and install twin cutter
5. Visually align the slot in the top of the twin
cutter so it is parallel to the lathe arbor.
Operation
A brake rotor is machined from its center
outward, cutting both faces at the same time.
1. Measure the rotor thickness with a
micrometer and determine the depth of cut
necessary to machine both surfaces.
2. Determine the minimum allowable thickness
(cast into the rotor, or from manufacturers
specifications) and do not machine down past
this minimum.
NOTE: When machining single piston or
floating caliper rotors, more metal may be
taken off one face than the other provided the
minimum overall thickness specification is
maintained.
3. Loosen the cross slide lock and turn the
crossfeed handwheel to back the twin cutter
out far enough to clear a mounted rotor.
4. Mount the rotor on the lathe arbor using the
appropriate adapters.
NOTE: The mounted rotor illustrated in Figure
4 is a non-vented type. Both vented and non-
vented rotors up to 1.75" (44.5 mm) thick may
be resurfaced with the 6950 twin cutter.
Figure 4 – Lathe set up for rotor turning
5. Center the rotor between the tool bits by
positioning the twin cutter to the left or right
along the cast slot (or by adjusting the spindle
feed handwheel).
6. Install a rotor silencer to dampen machining
vibrations.
7. Set the lathe V-belt to the correct groove for
optimum speed and finish. Refer to the lathe
operations manual for proper speeds and
feeds. Generally, slow speeds give a better
finish and longer life.
Dial set to cut 4/1000
of an inch(0.004")
Dial set to cut 1/10
mm (0.1 mm)
Micrometer
Inner
Sleeve
Tool Bit Holder
Nut
Self-Aligning Washers
Crossfeed
Handwheel
Upper Clamp
Lower Clamp
Spindle Lock
Boring Bar
Remove Clamps and Bar Install Twin Cutter
Rotor
Tool Holder
Lock Knobs
Slot Centers Twin
Cutter to Rotor
Cross Slide
Lock Knob
Safety Shield
Must Be Used