Tc 9-524 fundamentals of machine tools

Band Filing Speed
Band files should be run at relatively slow speeds as
compared to speeds used for band sawing. Figure 6-21 lists
recommended speeds for band filing. Note that, in general,
the slower speeds are used for filing harder metals and faster
speeds are used for filing softer metals.
Band Filing Feeds
Work pressure on the band file should not be excessive. A
medium amount of pressure applied against the band file
moving at the proper speed will produce curled chips which
will not clog the file. Heavy pressure will cause clogging
and can cause the file to break or the machine to stall. A
light pressures should be used for finish filing, with a slow,
sideways motion that will not leave vertical file marks on the
workpiece.
6-17

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TC 9-524
POLISHING
Polishing bands and a polishing attachment are provided
with the vertical band saw machine so that light polishing
can be performed. The polishing bands are intended
primarily for removing saw marks on the cut edges of
workpieces.
Polishing Speeds
Move polishing bands at speeds between 75 and 260 FPM,
the faster speeds being used for softer materials and the
slower speeds being used for harder materials.
Polishing Feeds
Feeds should be light for polishing. Use a slow, sideways
motion so that the polishing band will leave no marks on the
workpiece. If the band does not remove the tool marks
quickly, change to a coarser polishing band.
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TC 9-524
Chapter 7
LATHES
The lathe is a machine tool used principally for shaping articles of metal (and sometimes wood or other materials) by causing
the workpiece to be held and rotated by the lathe while a tool bit is advanced into the work causing the cutting action. The basic
lathe that was designed to cut cylindrical metal stock has been developed further to produce screw threads. tapered work. drilled
holes. knurled surfaces, and crankshafts. The typical lathe provides a variety of rotating speeds and a means to manually and
automatically move the cutting tool into the workpiece. Machinists and maintenance shop personnel must be thoroughly familiar
with the lathe and its operations to accomplish the repair and fabrication of needed parts.
TYPES OF LATHES
lathe (Figure 7-1 ) is ideally suited for this purpose. A trained
Lathes can be divided into three types for easy identification:
operator can accomplish more machining jobs with the
engine lathes, turret lathes, and special purpose lathes. Small
engine lathe than with any other machine tool. Turret lathes
lathes can be bench mounted, are lightweight, and can be
and special purpose lathes are usually used in production or
transported in wheeled vehicles easily. The larger lathes are
job shops for mass production or specialized parts. while
floor mounted and may require special transportation if they
basic engine lathes are usually used for any type of lathe
must be moved. Field and maintenance shops generally use a
work. Further reference to lathes in this chapter will be about
lathe that can be adapted to many operations and that is not too
the various engine lathes.
large to be moved from one work site to another. The engine