17
Note:
most often, the discard diameter is cast into the brake drum, not the
maximum machining diameter.
3. Inspect brake drum. do not attempt to machine a drum that is damaged or in
poor condition.
Mounting Drums
1. Loosen the boring bar clamp nut and push the boring bar all the way into
the clamp.
2. Mount the drum on the arbor using the proper adapters, cones, and
spacers. Use examples in Figure 15 for guidance.
3. Wrap the drum silencer band
snugly around the drum. Be sure
it covers up to the right-hand
edge.
Figure 12-Attach silencer band
4. Position the cross slide and spindle by turning the cross feed handwheel to
maximum clockwise position. Then back off the cross feed handwheel 2
complete turns.
5. Position the boring bar by loosening the boring bar clamp nut and sliding the
boring bar inward toward the drum until the tool bit is close to the drum .
The boring bar position is changed whenever a drum of different diameter is
machined.
The entire boring bar clamp may
also be swiveled to achieve the best
cutting position.
Figure 13 - Positioning the boring bar
