Issue link: http://metalfinishing.epubxp.com/i/49721
stop rotating. On an indexing rotary machine, because of the stop, dwell, and start cycle, production is lower. Parts that have surfaces that are difficult to reach and require more dwell time in certain areas may be finished on an indexing rotary machine to obtain the dwell time necessary. On each table there are rotating spin- dles on which the parts are fixtured for the finishing sequence. Rotary tables may have a greater number of fixtures than indexing tables, since the production and simple configuration make it more appropriate to be run on a continuous machine due to the ease of reaching all surfaces. Straight Line Machines There are various types of straight-line automatic finishing machines. Normally, linear workpieces are finished on straight-line machines. Straight-line machines also can be used to finish round parts if extremely high production is required. There is less limitation on workpiece size as with rotary equipment. With straight-line automatic machines, finishing heads can be placed on both sides of the machine. In addition, various heads can be incorporated into the system for buffing and polishing. With rotary equipment, the outside periph- ery of a rotary table is used. Various types of straight line machines include: Horizontal return straight line Narrow universal straight line Over and under universal straight line Reciprocating straight line Open-center universal The size or length of these straight-line machines can be designed and built to accommodate the desired end result; floor space is the only major limitation. Each machine normally requires only one operator for load/unload. All operations of these machines are controlled from a push-button panel located near the oper- ator for starting, stopping, and controlling various functions. COMPUTER NUMERICAL CONTROL BUFFING MACHINES Buffing machine manufacturers can build equipment offering the same levels of control and flexibility available from computer numerical control (CNC) metal- cutting machines. Separate CNC workcells can be designed to combine buffing with deburring operations within a given and limited series of process steps. It also is possible to integrate a complete sequence of manufacturing operations through a universal, plant-wide parts handling system to combine fabricating, machining, deburring, polishing, buffing, painting, plating, and packaging. Such systems have a significant impact on material handling costs, daily in-process inventory levels, direct labor costs, plant floor space requirements, safety, and over- all productivity. CNC buffing systems offer a number of significant advantages. Equipment is programmed on the shop floor for reduced setup time. Buffing cycles can be reprogrammed to accommodate changing production requirements. Production data are automatically collected to support statistical process control require- ments. Most important, quality is improved because part-to-part tolerances are consistent and repeatable. WORKPIECE HANDLING Significant advancements have been made in materials handling technology as it relates to buffing. A broad range of application-specific options is offered. These include pick-and-place workpiece load/unload systems, "blue steel" roller conveyor systems, lift-and-carry and shuttle-type in-line part transfer systems, trunnion- 43