PRECISION GRINDING MACHINES
CHAPTER LEARNING OBJECTIVES
Upon completing this chapter, you should be able to do the following:
Describe speeds, feeds, and coolants used while grinding.
Describe and explain the use of surface grinders.
Describe and explain the use of cylindrical grinders.
Describe and explain the use of tool and cutter grinders.
up the work in the machine. The setup procedures will
Modern grinding machines are versatile and are
vary with the different models and types of machines.
used to perform work of extreme accuracy. They are
Study the manufacturer's technical manual to learn
used primarily to finish surfaces that have been
specific procedures for a particular model of machine.
machined in other machine tool operations. Surface
grinders, cylindrical grinders, and tool and cutter
As with any shop equipment you must observe all
grinders can perform practically all of the grinding
posted safety precautions. Review your equipment
operations required in Navy repair work.
operators manual for safety precautions and any
chapters of Navy Occupational Safety and Health
To perform these operations, you must know the
(NAVOSH) Program Manual for Forces Afloat,
construction and principles of operation of commonly
OPNAV Instruction 5100.19B, that apply to the
used grinding machines. You gain proficiency in
grinding through practical experience. Therefore, you
should take every opportunity to watch or perform
grinding operations from setup to completion.
GRAIN DEPTH OF CUT
There are several classes of each type of grinder.
The SURFACE grinder may have either a rotary or a
reciprocating table and either a horizontal or a vertical
On most ships, stowage space is limited. Con-
spindle. CYLINDRICAL grinders may be classified as
sequently, the inventory of grinding wheels must be
plain, centerless, or internal grinders; the TOOL AND
kept to a minimum. It would be impractical and
CUTTER grinder is basically a cylindrical grinder.
unnecessary to keep on hand a wheel for every grinding
Those generally found in Navy machine shops are the
job. With a knowledge of the theory of grain depth of
reciprocating table grinder, the horizontal spindle
cut you can vary the cutting action of the various wheels
(planer type) surface grinder, the plain cylindrical
and with a small inventory can perform practically any
grinder, and the tool and cutter grinder. Shops also may
grinding operation that may be necessary.
have a universal grinder, which is similar to a tool and
For ease in understanding this theory, assume that
cutter grinder except that it is designed for heavier work
a grinding wheel has a single grain. When the grain
and usually has a power feed system and a coolant
reaches the point of contact with the work, the depth of
cut is zero. As the wheel and the work revolve, the grain
Before operating a grinding machine, you must
understand the underlying principles of grinding and
until it reaches a maximum depth at some point along
the purpose and operation of the various controls and
the arc of contact. This greatest depth is called the grain
depth of cut.
parts of the machine. You also must know how to set