An NC drill press drills four 10.0mm diameter boles at four locations on a flat aluminum plate In a production work cycle. Although the plate is only 12 mm thick, the drill must travel a full 20 mm vertically at each hole location to allow for clearance above the plate and breakthrough of the drill on the underside of the plate. Cutting conditions: speed "" 0.4 m/sec and feed = 0.10 mm/rev. Hole locations are indicated in the following table:
The drill starts out at point (0.0) and returns to the same position after the work cycle is completed. Travel rate of the table in moving from one coordinate position to another is 500 mm/min. Owing to effects of acceleration and deceleration and the time required for the control system to achieve final positioning, a time loss of 3 seize patience at each stopping position of the table, Assume that al1ll1ove~are made to minimize the total cycle time If loading and unloading the plate take 20 sec (total handling time. determent the time required for the work cycle.