Snap-on • 7
Starting the Lathe
The toggle switch, above the drum slide handwheel,
turns the lathe ON and OFF.
Slide Travel
The drive motors of the slides are on when the tog-
gle switch is in the ON position. The slides will move
through their full travel with a few turns of the hand-
wheels when the slide engagement knobs are loose.
When the slide engagement knobs are tightened, the
slides will feed in an outward direction until the slide
engagement knobs are loosened or the slides reach
the end of their travel.
Note:
To prevent undue wear, DO NOT allow the
lathe to run for extended periods with the slides at the
end of their travel and the feeds engaged. The slide
engagement knobs are tight. See how-to-use details
under reconditioning disc brake rotors and recondi-
tioning brake drums.
Tool Bar Depth-of-Cut Micrometer Dial
The tool bar depth-of-cut micrometer dial is cali-
brated with both inch and metric scales. The depth-of-
cut dial indicates the amount of material being cut
from one side of a drum or rotor.
Inch Scale:
A cut of .002" (one micrometer division) from an 8"
drum will result in a refinished diameter of 8.004"
Metric Scale:
A cut of .05 mm (one micrometer division) from a
209 mm drum will result in a refinished diameter of
209.1 mm.
Arbor Installation
The 1" arbor shipped with the lathe has been care-
fully matched to the spindle of the lathe during final
assembly and testing. Witness marks have been
etched onto the arbor and spindle for repeatable, pre-
cise alignment.
The witness marks should be carefully aligned when
installing the arbor. A true running arbor is essential to
professional quality brake drum and rotor recondition-
ing.
The drawbar, which can be tightened or loosened at
the rear of the spindle, pulls the hardened and ground
taper of the arbor into the ground taper seat of the
spindle.
Rotor Mounting
Review the descriptions of typical rotor mounting
configurations. The same directions apply when
mounting a brake rotor. Hubbed rotors are mounted
on adapters that fit into the bearing races. Hubless
rotors use a cone in the center hole and a hubless
adapter on each side of the rotor. Spacers are used to
fill out the arbor shaft so that the arbor nut can be
tightened. The setups illustrated in Figure 4 are typical
of the many mounting configurations necessary to
meet the requirements of brake rotor reconditioning.
The adapters, cones, and spacers supplied with the
lathe will allow reconditioning of the majority of the
rotors found on current production vehicles. Optional
adapters, cones, and spacers are available to meet
special needs.
Note:
Adapters may also be used as spacers to fill
out the arbor shaft if care is taken to prevent damage
to their machined surfaces.
The patented self-aligning spacer prevents diagonal
thrust on the adapters. The self-aligning spacer should
always be used adjacent to the arbor nut.
Brake Lathes
