Figure 4-22.--Disk-cutting attachment.
Figure 4-23.--Polish finishing.
be well acquainted with the types of machines and the
cutting attachment in use. The device consists of a
methods and techniques of operation of drill presses
radius arm, a movable pivot point, and a suitable
and drills found in Navy machine shops.
clamp to attach the assembly to the saw guidepost. To
cut a disk using this device, lay out the circle and
A diverse group of people with different training
punch a center point. Clamp the radius arm to the
and experience backgrounds use the drill press.
Because of that some unsafe operating practices have
the saw teeth are tangent to the scribed circle. Adjust
become routine in spite of the possibility of serious
the pivot point radially and vertically so that it seats in
injury. The basic safety precautions for the use of a
the center-punch mark; then clamp the pivot point
drill press are listed below:
securely. Then rotate the work around the pivot point
Always wear goggles or safety glasses, and
to cut the disk.
wear ear protection when warning signs are
FILING AND POLISHING.--In filing and
polish finishing, you will manually feed and guide the
work to the band. Proper installation of the guides
Keep loose clothing clear of rotating parts.
and backup support strips is very important if you
NEVER attempt to hold a piece being drilled
expect good results. A guide fence similar to the one
in your hand. Use a vise, hold-down bolts or
other suitable clamping device.
close tolerances. Be sure to wear goggles or an eye
protection shield to file and polish, and above all, be
Check the twist drill to be sure that it is
careful of your fingers. For proper band speeds and
properly ground and is not damaged or bent.
work pressures, consult the manufacturer's technical
Make sure the cutting tool is held tightly in the
manual for the machine you are using.
drill press spindle.
Use the correct feeds and speeds.
DRILLING MACHINES AND DRILLS
When feeding by hand, take care that the drill
Although drilling machines or drill presses are
does not dig in and take an uncontrolled depth
commonly used by untrained personnel, you cannot
assume that you will operat these machines
proficiently if you simply insert the proper size drill
Do not remove chips by hand. Use a brush.
and start the machine. As a Machinery Repairman,
The two types of drilling machines or drill presses
you will be required to perform drilling operations
common to the Navy machine shop are the upright
with a great degree of accuracy. Therefore you must