OO-M-340 Milling, Grinding, Drilling, And Slotting AttachmentThis specification covers an electric motor driven attachment for milling, grinding, drilling, slotting, boring, gear cutting, thread milling, and keyseating operations. The attachment is adaptable for mounting on a lathe, planer, or boring mill. This attachment may also be used as a portable self-contained unit suitable for bench mounting when provided with a feed table.

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OO-M-340F

more than 30 minutes.  Surface finish shall not be rougher than 16 microinches aa.  A minimum of six spindle speeds shall be provided.  A grinding wheel shall be furnished that will allow this requirement to be accomplished.

3.8.6  Dividing head.  The dividing head shall be adaptable to fit 1-3/8 inch diameter lathe spindle bores.  The head shall be furnished with one machined adapter for a 1-3/8 inch bore spindle and three unfinished adapters to cover a range of 1-1/8 inches to 3-1/2 inches.  The dividing head shall be capable of indexing all divisions from 1 to 50, inclusive, and divisions 55 to 120 by multiples of five.  The dividing head shall be indexed by degrees (360 equal divisions), 1/2 degree (720 equal divisions), and 1/3 degree (1,080 equal divisions).  Positioning error shall be not greater than

1/2 minute of one degree (30 seconds).

3.8.7  Internal keyseater and slotter.  The internal keyseater shall be capable of cutting a standard internal keyway as listed in table V in the bore size for which it is standard, for a length up to

1-1/2 times the bore diameter as listed in ASME B17.1.  Sizes 1 and 2 shall have a stroke adjustable from 0 to 4 inches.  The keyseater and slotter shall be capable of being securely mounted on the basic attachment and of being locked in position to provide strokes of any angle in relation to the base mounting surface.  The necessary cutters and tool bits shall be included to cut each of the internal keyways specified below in table V for both sizes 1 and 2.  The keyseater and slotter shall be capable of cutting the keyseats specified in table IV in the specified bores of 1020 steel in not more than five minutes.  The surface finish shall not exceed 125 microinches aa.

TABLE V.  Internal keyway dimensions.

3.8.8  Feed table.  The feed table shall be capable of being mounted to the basic attachment to create a portable machining unit.  The feed table shall consist of a base, a lower carriage that shall travel longitudinally in relation to the base, an upper carriage that shall travel across the base, and the necessary screws, screw blocks, anti-backlash nuts, and gibs to equip it to meet the accuracy and performance specified herein.  The base shall be capable of being rigidly bolted or clamped to a supporting surface without interfering with the movement of either carriage.  The lower carriage shall provide travel of not less than 3 inches at 90 degrees to the direction of

travel of the lower carriage.  A means of locking at any point in either direction of travel shall be provided.  Locking either carriage shall not deflect the basic attachment more than 0.001 inch. Feed shall be provided with a graduated collar or dial similar in form and marking to that specified for vertical travel of the basic unit.  Each collar shall be capable of being set at 0 at any point of the carriage travel.  Travel, as indicated by either collar, shall be accurate within 0.005 inch per inch of travel.  The basic head, when mounted on the feed table, shall permit cutting the

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