TM 9-3418-200-14 & P
Lift and turn the pawl so that the arrow points in the direction of the proposed feed, in this case from left to right. Turn the
handwheel making a complete stroke, forward and back, to make sure that everything is clear and in order that the ram
does not strike the work. You are now ready to start the machine and make the first surface cut on the work.
If it becomes necessary at any time during the surfacing or machining of the work to stop the machine while it is still
cutting, first lift the pawl disengaging the automatic feed (fig. 39) before stopping the machine. This will avoid stopping the
ram in the middle of a cutting stroke which could damage the cutting edge of the tool.
THE ROUGHING CUT
A roughing cut is one made primarily to prepare the surface of the work for a final or finishing cut. The appearance of the
surface is of minor importance. Roughing cuts may consist merely of taking one or more cuts in order to remove
irregularities on castings leaving the surface fairly straight and level, or preparing it for a finishing cut. Roughing cuts may
consist of several heavy cuts when excess metal is to be removed from the surface.
The edge at the end of the cut, especially on cast materials, is likely to break off leaving the edge ragged. This condition
can be avoided by beveling the edge, using a file as shown in figure 40. Shaper must not be in operation when this is
done.
THE FINISH CUT
The finishing cut is one made for the purpose of machining the work to size and at the same time giving it a good smooth
surface.
The amount of material which must be removed in a finishing cut is dependent upon the surface left by the last roughing
cut. Ordinarily between ten and fifteen thousandths is left for removal with the finishing cut.
THE VERTICAL CUT
Vertical cuts are used for squaring the ends of long cuts, for squaring shoulders, and for cutting slots in keyways etc. , (fig.
31-A).
There are two ways in which a vertical cut may be shaped. First, and most frequent, the tool is fed to the work in a
downward direction by means of the down feed screw. In the second method, the work is fed to the tool, by means of the
table elevating screw, (fig. 42). When using this second method be sure that the work is not elevated too far so that it is
struck by the ram.
THE BEVEL CUT
The most common method of producing an angular or bevel cut is to swivel the tool head and produce the bevel by
feeding in an angular direction with the down feed crank.
The tool head is swiveled by releasing the lock-screw (fig. 43) and turning the head to the desired angle using the
graduated dial as shown. Retighten the lock-screw. The tool is then fed by turning the feed handle as shown in figure 44.
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