MAHLE RTI BRC450 - Manual (Page 15)

Page 13
G. Setting up for cutting. With the auto feed dis-engaged (See Figure 1) manually turn the wheel,
moving the cutting tool slide and the cutting tips to a position almost touching the rotor’s largest
diameter. Note that there are two locking levers, one on the top of each cutting tool holder along with
a graduated adjusting knobs. Move each tool holder so that the cutting tips are very close, but not
touching each side of the rotor--then move the tool slide and cutting tips so that they are approximately
1/4" (6 mm) inside the rotor’s largest diameter braking surface.
H. Initial surface cut. With the cutting tips approximately 1/4" (6 mm) inside the rotor’s largest diameter
braking surface, with each tip close but not touching the rotor’s surfaces, start the lathe by pushing the
green start switch. With the rotor now rotating, unlock the lever and turn the adjusting knob to move
the tool holder with the lever loosened until the cutting tip just “kisses” the rotor surface. This can be
determined by sound and sight. Lock down the lever and loosen the other tool holder lever, moving the
cutting tip with the adjusting knob similarly until the second cutting tip also just “kisses” the other rotor
surface. Lock down the lever. Now, manually move the tool slide outward by turning the hand wheel
very slowly. This will remove any “ridge” on the outside edge of the rotor. (If the ridge is particularly
large, this may require that the cutting tips be moved outward and then inward with several passes.
In this case, after removing the ridge, stop the lathe rotation and repeat the initial surface cut set up.)
I. Checking rotor surface. Once the initial surface cut set-up is complete and the ridge is removed,
manually move the tool slide inward by turning the hand wheel very slowly. (If the depth of cut
increases significantly as the cutting tip moves inward, the rotor is warped or tapered. In this case, stop
and move the cutting tool outward to compensate.) When both cuttings tips reach past the smallest
diameter of the braking surfaces, stop the manual rotation of the hand wheel. (Note that it is common
for one cutting tip to reach this point before the other. As long as one tip does not touch the rotor hat,
continue until the manual rotation of the hand wheel until both tools are inside the edge of the braking
surfaces on both sides of the rotor. If one tip hits the rotor hat before this is accomplished, it will be
necessary to slide that cutting tip’s tip holder outward by loosening the two Allen locking screws.)
J. Setting Depth of Cut. Note that the adjusting knob is calibrated with numbered “large” graduations.
These long lines denote 0.004" (0.10 mm) of tool holder and tip movement. The shorter lines half way
in between therefore denote 0.002" (0.05 mm). At this point, the operator has the choice of a “one
pass” or a “multi-pass” technique. In order to perform a “one pass” cut, the operator must estimate the
depth of cut that will remove run out, taper, and grooves noted during the rotor surface checked during
manual hand wheel rotation, and to determine if that cut will or will not result in the rotor being too thin
(Less than manufacturer’s discard thickness.) Since this is a complex procedure to estimate the exact
depth, without cutting more than is needed and wasting valuable rotor thickness, it is recommended
that the a “multi-pass” technique be used. To perform the first pass of a “multi-pass” technique, move
each cutting tip inward 0.004" (0.10 mm) or one large graduation by unlocking one lever, rotating the
adjusting knob, locking that lever and repeating the procedure for the other tool holder. Now engage
the auto feed. The tools will move outward while cutting. Note that the BRC450 can cut much deeper
than 0.004" (0.10 mm) on each side. The depth of cut is limited only by the drive motor’s torque and
the condition of the rotor. It is suggested that the maximum cut on each side be limited to 0.008" (0.20
mm) particularly for the first pass. If this first “rough cut” does not cut the entire surface of the rotor
and remove all grooves, then move the tool slide inward manually and repeat the procedure as
required. Once there is a rough cut surface over the entire rotor surface and all grooves are removed,
now check to see if the rotor is too thin.